Battery longevity
02-15-2006, 12:35 AM
#26
RE: Battery longevity
I guess we do have it better than others out here in the crazy state as far as flying goes. Sometimes I guess I forget that. Even so, just curious as to how well the batteries fared last season with those who flew electric.
Before I got into electric flying I heard a lot of claims about how long they should last, but I haven't seen much proof yet. It's not that I'm not satisfied with how my batteries are doing, but I am wondering if mine are the exception or the rule.
Before I got into electric flying I heard a lot of claims about how long they should last, but I haven't seen much proof yet. It's not that I'm not satisfied with how my batteries are doing, but I am wondering if mine are the exception or the rule.
02-15-2006, 08:04 AM
#27
Senior Member
My Feedback: (6)
Join Date: Jul 2002
Location: Nineveh,
IN
Posts: 574
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
Actually this is the main reason some haven't tried to go EP because of the fear of short battery life but from what we're seeing is unjustified. I had heard last year that they only expected to have life cycles of 100-150 for these big batteries, but I feel that was a misleading statement. The biggest problem as I see it was that most flyers last year had so many packs (4-6 sets of 10S) that they didn't put many cycles on each pack, most only having in that season about 90-100 cycles which equaled 400-600 flights, with this many packs it could take 2,3 or even 4 seasons to get any real #'s on battery life. Which would then even put another factor in the mix, being the # years the packs could last (and winter storage). What I expect to see this year is more people using only 2 sets, making less batteries with more cycles per set. We're in a little different situation than most Lipo users, most are using 2sand 3s pack's in smaller foamy's and such, 95% of lipo business. What I've read is that if you keep the temps down, use a standard setup that is proven to work, amps in the right #'s, and short flights (not over 80% capacity, my thought is we could see maybe 400-500 cycles and maybe more. Reason for this is even flyer's that fly alot will be hard pressed to fly more than 600-1000 flights a season.
I'm sure that your reason for asking the question is to compare the price of EP to glow.
So the big question is will the $'s even out or possibly be cheaper in the long run for EP, I think once this is answered we will see most if not all going EP in pattern.
For me break even # would be about 2 seasons with 2 sets of batteries= fuels cost only, not any maintance. I would be very happy with buying 2 sets of batteries every other year.
Sorry for being so long.
Steve Maxwell
I'm sure that your reason for asking the question is to compare the price of EP to glow.
So the big question is will the $'s even out or possibly be cheaper in the long run for EP, I think once this is answered we will see most if not all going EP in pattern.
For me break even # would be about 2 seasons with 2 sets of batteries= fuels cost only, not any maintance. I would be very happy with buying 2 sets of batteries every other year.
Sorry for being so long.
Steve Maxwell
02-15-2006, 09:18 AM
#28
Senior Member
RE: Battery longevity
ExFokkerFlyer,
I agree with you also. I must have interpreted your post wrong since it came after my post #12 where I stated that the 3200mAh cell was not a good solution for pattern flying. Adam from Dragonfly tends to tout ThunderPower solutions without any real data to back up the claims. The truth is that we never had a 5AH pack solution before. The Saehan cells used in the ThunderPower packs are good cells. In fact, we plan to release a new Cellpro Slimline series using these cells because the thin shape will work in places the Kokam or PolyQuest cells cannot fit. The new Slimline series should have been released in January but the U.S. owner of Saehan, Emerging Power, cannot produce the handmade cells in sufficient quantities, and, R/C is not their primary business.
To date, I am only aware of one plane in Europe that was built so light from carbon (as an e-pattern plane) that the 2p 6400mAh (using 3200 cells) pack worked for him. Personally, I don't consider this a mainstream solution and I didn't like the look of the custom-made e-pattern plane. A 5AH capacity seems to be the right choice so I am anxious to get these new packs tested this spring.
In the last post above, Steve seems to state what I believe is the mainstream problem with flying electric pattern planes. Unless you are a sponsored pilot, or have money to burn, the cost of flying electric pattern is far greater than flying a glow-powered plane. We feel that the new Kokam 4800mAh cell combined with the Cellpro or BalancePro systems will change that advantage. Educating users about cell temperature and true cell discharge ratings is also key to increasing pack longevity.
I agree with you also. I must have interpreted your post wrong since it came after my post #12 where I stated that the 3200mAh cell was not a good solution for pattern flying. Adam from Dragonfly tends to tout ThunderPower solutions without any real data to back up the claims. The truth is that we never had a 5AH pack solution before. The Saehan cells used in the ThunderPower packs are good cells. In fact, we plan to release a new Cellpro Slimline series using these cells because the thin shape will work in places the Kokam or PolyQuest cells cannot fit. The new Slimline series should have been released in January but the U.S. owner of Saehan, Emerging Power, cannot produce the handmade cells in sufficient quantities, and, R/C is not their primary business.
To date, I am only aware of one plane in Europe that was built so light from carbon (as an e-pattern plane) that the 2p 6400mAh (using 3200 cells) pack worked for him. Personally, I don't consider this a mainstream solution and I didn't like the look of the custom-made e-pattern plane. A 5AH capacity seems to be the right choice so I am anxious to get these new packs tested this spring.
In the last post above, Steve seems to state what I believe is the mainstream problem with flying electric pattern planes. Unless you are a sponsored pilot, or have money to burn, the cost of flying electric pattern is far greater than flying a glow-powered plane. We feel that the new Kokam 4800mAh cell combined with the Cellpro or BalancePro systems will change that advantage. Educating users about cell temperature and true cell discharge ratings is also key to increasing pack longevity.
02-18-2006, 01:46 AM
#29
My Feedback: (11)
Join Date: Jul 2003
Location: Tracy,
CA
Posts: 2,080
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
The cheapest place at this point for the Tp 5300's is www.dynamoelectrics.com
At 287.95 a pack.
As for the Kokam's, I have always found, in the smaller packs, that their ratings are off. They overstate things in my opinion.
Not that they aren't decent packs and don't have potential.
All battery manufacturers state bench tested ratings though and aren't accurate in the real world.
Hope to get more useful info on what this thread is about in the long run, not who think's their packs are better because of ratings.
Great idea for a thread Tom..
Chris
At 287.95 a pack.
As for the Kokam's, I have always found, in the smaller packs, that their ratings are off. They overstate things in my opinion.
Not that they aren't decent packs and don't have potential.
All battery manufacturers state bench tested ratings though and aren't accurate in the real world.
Hope to get more useful info on what this thread is about in the long run, not who think's their packs are better because of ratings.
Great idea for a thread Tom..
Chris
02-18-2006, 02:41 AM
#30
RE: Battery longevity
ORIGINAL: Greg Covey
ExFokkerFlyer,
I agree with you also. I must have interpreted your post wrong since it came after my post #12 where I stated that the 3200mAh cell was not a good solution for pattern flying. Adam from Dragonfly tends to tout ThunderPower solutions without any real data to back up the claims. The truth is that we never had a 5AH pack solution before. The Saehan cells used in the ThunderPower packs are good cells. In fact, we plan to release a new Cellpro Slimline series using these cells because the thin shape will work in places the Kokam or PolyQuest cells cannot fit. The new Slimline series should have been released in January but the U.S. owner of Saehan, Emerging Power, cannot produce the handmade cells in sufficient quantities, and, R/C is not their primary business.
To date, I am only aware of one plane in Europe that was built so light from carbon (as an e-pattern plane) that the 2p 6400mAh (using 3200 cells) pack worked for him. Personally, I don't consider this a mainstream solution and I didn't like the look of the custom-made e-pattern plane. A 5AH capacity seems to be the right choice so I am anxious to get these new packs tested this spring.
In the last post above, Steve seems to state what I believe is the mainstream problem with flying electric pattern planes. Unless you are a sponsored pilot, or have money to burn, the cost of flying electric pattern is far greater than flying a glow-powered plane. We feel that the new Kokam 4800mAh cell combined with the Cellpro or BalancePro systems will change that advantage. Educating users about cell temperature and true cell discharge ratings is also key to increasing pack longevity.
ExFokkerFlyer,
I agree with you also. I must have interpreted your post wrong since it came after my post #12 where I stated that the 3200mAh cell was not a good solution for pattern flying. Adam from Dragonfly tends to tout ThunderPower solutions without any real data to back up the claims. The truth is that we never had a 5AH pack solution before. The Saehan cells used in the ThunderPower packs are good cells. In fact, we plan to release a new Cellpro Slimline series using these cells because the thin shape will work in places the Kokam or PolyQuest cells cannot fit. The new Slimline series should have been released in January but the U.S. owner of Saehan, Emerging Power, cannot produce the handmade cells in sufficient quantities, and, R/C is not their primary business.
To date, I am only aware of one plane in Europe that was built so light from carbon (as an e-pattern plane) that the 2p 6400mAh (using 3200 cells) pack worked for him. Personally, I don't consider this a mainstream solution and I didn't like the look of the custom-made e-pattern plane. A 5AH capacity seems to be the right choice so I am anxious to get these new packs tested this spring.
In the last post above, Steve seems to state what I believe is the mainstream problem with flying electric pattern planes. Unless you are a sponsored pilot, or have money to burn, the cost of flying electric pattern is far greater than flying a glow-powered plane. We feel that the new Kokam 4800mAh cell combined with the Cellpro or BalancePro systems will change that advantage. Educating users about cell temperature and true cell discharge ratings is also key to increasing pack longevity.
You obviously missed a few of Adam's posts.....he was was of the first to post CBA plots of cycled packs (6000's Prolite cells) vs new packs back in September. If I remember correctly (I know he is planning on posting them shortly...but he is at my house building new planes....) it was around 3% after 50 cycles or so.....so your comments are a bit off base.
I just finished capacity testing my 5300's vs new packs yesterday and will post the results here shortly as well, but it appears to be about 3-5% loss in 50-70 cycles.
The tests we do are on real packs, use in the Worlds, US Nats and dozens of other events....well travelled well abused packs (I have discharged mine to 90%+ more than once by accident) so its not some hand picked company performed test.
If you have data like we do to back up your claims from people in the field please provide it.
Unless you come up with new tech in cell chemistry the cycle life of current cells is not going to improve much with chargers/balancers......my packs have always remained within 0.010V balance during their life (checked with a calibrated Fluke DVM)....and I have yet to see them reach beyond about 120-130F after a flight. Average 5-6C and burst to maybe 12C.
02-18-2006, 11:59 AM
#31
Senior Member
Join Date: Apr 2003
Location: Saskatoon,
SK, CANADA
Posts: 722
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
Greg, now that RCgroups' search function is back, I can educate you. Here is the degradation of the Thunder Power Pro Lite 5s3pV 6000mAh pack used in F3A flights in an F3A airplane in F3A competition (Muncie heat, French wind, Calgary altitude...) - THE most demanding use of a battery. A lot more demanding than a 90-size plane flown in a non-F3A class.
http://www.rcgroups.com/forums/showthread.php?t=404452
Am I biased? I work for Draganfly Innovations, and we are the Canadian distributor of Thunder Power. I am sponsored by Thunder Power. Obviously I'm going to choose Thunder Power packs for my airplanes, and for others'. But I also own a CBA and put cycles on batteries, and brought useful data to help answer the question on every pattern pilot's mind.
Danny Landis is having success with his Tanic batteries: http://www.rcgroups.com/forums/showthread.php?t=479695 (post #16).
Adam Glatt
http://www.rcgroups.com/forums/showthread.php?t=404452
Am I biased? I work for Draganfly Innovations, and we are the Canadian distributor of Thunder Power. I am sponsored by Thunder Power. Obviously I'm going to choose Thunder Power packs for my airplanes, and for others'. But I also own a CBA and put cycles on batteries, and brought useful data to help answer the question on every pattern pilot's mind.
Danny Landis is having success with his Tanic batteries: http://www.rcgroups.com/forums/showthread.php?t=479695 (post #16).
Adam Glatt
02-18-2006, 05:56 PM
#33
Senior Member
RE: Battery longevity
I think we may be talking "apple and oranges" here which is why we have some disagreement.
If you don't stress the pack through high temperature and rated current draw, they will last much longer. When going head-to-head, the ThunderPower cells produce more heat at their rated current delivery, if they can even meet that deliver without bloating. There are some Kokam cells that also do not meet their rated delivery, but they do not bloat. When you parallel enough cells together, you can create a pack that meets (or exceeds) your needs, but the weight advantage of the so-called lighter cell is lost.
Here is a single link to the Wattflyer [link=http://www.wattflyer.com/forums/showthread.php?t=1661]Battery Vault[/link]. Look at not just the discharge currents but also the temperatures and summary comparison links. Soon, cycle life data will be posted here and you may be quite shocked.
Lastly, reguardless of the cell chosen, monitoring each cell on both discharge and charge balancing is the best way to protect the pack. Adapters will soon be available to utilize this technique on ThunderPower and PolyQuest cells. Any one pack or few packs can stay in balance depending upon the use, abuse, handling, and manufacturing lot. The cells all age differently as they are exposed to different criteria like outside handling abuses and inside temperatures. Once this happens, it becomes even more important to safely operate the pack within the limits of the weakest cell.
If you don't stress the pack through high temperature and rated current draw, they will last much longer. When going head-to-head, the ThunderPower cells produce more heat at their rated current delivery, if they can even meet that deliver without bloating. There are some Kokam cells that also do not meet their rated delivery, but they do not bloat. When you parallel enough cells together, you can create a pack that meets (or exceeds) your needs, but the weight advantage of the so-called lighter cell is lost.
Here is a single link to the Wattflyer [link=http://www.wattflyer.com/forums/showthread.php?t=1661]Battery Vault[/link]. Look at not just the discharge currents but also the temperatures and summary comparison links. Soon, cycle life data will be posted here and you may be quite shocked.
Lastly, reguardless of the cell chosen, monitoring each cell on both discharge and charge balancing is the best way to protect the pack. Adapters will soon be available to utilize this technique on ThunderPower and PolyQuest cells. Any one pack or few packs can stay in balance depending upon the use, abuse, handling, and manufacturing lot. The cells all age differently as they are exposed to different criteria like outside handling abuses and inside temperatures. Once this happens, it becomes even more important to safely operate the pack within the limits of the weakest cell.
02-18-2006, 06:22 PM
#34
RE: Battery longevity
Greg,
One thing to keep in mind is that unlike some of our RC bretheren, most pattern EP set ups require extensive use of throttle management techniques. Max current discharge is generally only reached when testing the system. My last set up was propped at 85 amps WOT, but the only time I ever hit that was testing prior to the first flight with the wattmeter. After that, the most I ever hit in flight was closer to 60-65 amps for short (2-5 seconds) bursts. My TPs 5s3p 6000s are rated in the area of 67 max cont... for level flight I was well under that, only in the verticals did I even approach that number and likely was never close due to the throttle curve.
My point is, batteries bloating at max current draw... which batteries do or don't, is of little importance for our purposes here. I understand what you are saying, touting that FMA's batteries stoutness beats TPs in those tests. But as has been said before, it really matters very little if we can't use your batteries because they are either too small in capacity or to heavy in weight on the other end of the scale. It will be interesting how the 5000's you mentioned will come out. Will they not have the same cells as the TPs?
As far as the TPs giving off more heat, that very well may be true. All I can say about that is during my flights this summer, I never had a pack go over 125 F... and that is in OAT of up to 105 F or so... so again, at least for me, not a problem.
I am looking forward to seeing those adapters you mentioned though. Will there be an airborne unit monitoring the discharge? If so, how much will it weigh?
Thanks for the info.
One thing to keep in mind is that unlike some of our RC bretheren, most pattern EP set ups require extensive use of throttle management techniques. Max current discharge is generally only reached when testing the system. My last set up was propped at 85 amps WOT, but the only time I ever hit that was testing prior to the first flight with the wattmeter. After that, the most I ever hit in flight was closer to 60-65 amps for short (2-5 seconds) bursts. My TPs 5s3p 6000s are rated in the area of 67 max cont... for level flight I was well under that, only in the verticals did I even approach that number and likely was never close due to the throttle curve.
My point is, batteries bloating at max current draw... which batteries do or don't, is of little importance for our purposes here. I understand what you are saying, touting that FMA's batteries stoutness beats TPs in those tests. But as has been said before, it really matters very little if we can't use your batteries because they are either too small in capacity or to heavy in weight on the other end of the scale. It will be interesting how the 5000's you mentioned will come out. Will they not have the same cells as the TPs?
As far as the TPs giving off more heat, that very well may be true. All I can say about that is during my flights this summer, I never had a pack go over 125 F... and that is in OAT of up to 105 F or so... so again, at least for me, not a problem.
I am looking forward to seeing those adapters you mentioned though. Will there be an airborne unit monitoring the discharge? If so, how much will it weigh?
Thanks for the info.
02-18-2006, 06:34 PM
#35
RE: Battery longevity
Oh and one other thing...
I keep reading that only sponsored guys are going electric, and that the costs otherwise are prohibitive for electric pattern. I really take exception to that. It is expensive, I'll grant you that... but have you ever tried to buy, mount, maintain, and feed a big YS 140 or 160? Great motors, don't get me wrong loved most of mine
, but they are expensive too! I would put my set up against a new YS set up and when you include the fuel for the year, I'm cheaper... I can't touch a OS 140, I agree... but there are other costs that most people do not take into consideration.
How long do airframes last with vibration? Servos? How much damage can fuel and oil soaking do? I have an Eclipse that has to undergo a rebuild due to vibration after 200 or so flights because of the YS... that won't happen with an electric. Provided no midaires, dumb thumbs, or forgetting to plug in the ailerons (wonder who would do that???)... the things will last forever!
Anyhoo... I just don't agree that all electric set ups are prohibitively expensive or that you have to be a sponsored guy or independently wealthy to afford it. To me, it can pay for itself over a couple of seasons... particularly if the batteries last 2-300 cycles... which was the whole point of this thread anyway.
Sincerely,
Tom
I keep reading that only sponsored guys are going electric, and that the costs otherwise are prohibitive for electric pattern. I really take exception to that. It is expensive, I'll grant you that... but have you ever tried to buy, mount, maintain, and feed a big YS 140 or 160? Great motors, don't get me wrong loved most of mine
, but they are expensive too! I would put my set up against a new YS set up and when you include the fuel for the year, I'm cheaper... I can't touch a OS 140, I agree... but there are other costs that most people do not take into consideration.How long do airframes last with vibration? Servos? How much damage can fuel and oil soaking do? I have an Eclipse that has to undergo a rebuild due to vibration after 200 or so flights because of the YS... that won't happen with an electric. Provided no midaires, dumb thumbs, or forgetting to plug in the ailerons (wonder who would do that???)... the things will last forever!
Anyhoo... I just don't agree that all electric set ups are prohibitively expensive or that you have to be a sponsored guy or independently wealthy to afford it. To me, it can pay for itself over a couple of seasons... particularly if the batteries last 2-300 cycles... which was the whole point of this thread anyway.
Sincerely,
Tom
02-18-2006, 06:44 PM
#36
Senior Member
My Feedback: (6)
Join Date: Jul 2002
Location: Nineveh,
IN
Posts: 574
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
Tom there is a good discussion on this subject on the NSRCA mailing list right now arckives and joining the list [link]http://www.nsrca.org/discussionA.htm[/link]
Steve Maxwell
Steve Maxwell
02-19-2006, 09:51 AM
#37
Member
Join Date: Sep 2003
Location: WHEATON,
MD
Posts: 43
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
While I don't fly models that require high current from their power plants, I have three Thunder Power packs that have failed me @ less than 4C discharge rate on take off and less than 3C their rated discharge rate while in flight.
Mind you, these packs have been pampered all throughout their life as my method of charging is to do so @ 70% of 1C and discharge them at less than 50% their stated "safe" discharge rated as specified by its manufacturer. All my Li-Pos have been treated the same way since first purchased almost three years ago.
While Kokams, TPEs, and others are still serving me well, only the ones failing me are the Thunder Powers. I have three of their packs that refuse to take a charge, and three that are following the same path. No bloating has been observed on any of the failed packs or the ones on their way there.
One more thing, one that to me is of paramount importance. The treatment I received from Thunder Power when I e-mailed them to find a solution to this problem was appaling at best. Their reply simply was "Our product is guaranteed for 60 days, if your packs are older than 60 days they are not covered by the warranty". That reply was typed in ALL CAPS, without regards for grammar, punctuation or spelling. It made the reading a rather annoying experience based on that fact alone, the substance of the message just added to my annoyance.
Calling them over the telephone was worse than reading their reply. It got me nowhere. What I demand from a manufacturer that is willing to print claims on their packs regarding continuous as well as burst discharge rate for their Li-Po packs is HONESTY, not hype. I base my decision to buy a battery pack on the needs for the particular aircraft it will be used in. This particular manufacturer chose to print "Made in U.S.A." on their packs knowing full well the cells are made in Asia not the U.S.A. What other things am I being misled about their Li-Po packs?
I trusted what was printed on the label implicitly. I also trusted their C rating as printed on the labels, and based on that information I chose Thunder Power for some of my models. Those models are now being re-fitted with better battery packs. I can assure everyone that I will never purchase a product from a manufacturer that chooses to non chalantly mislead their clients.
I will never patronize Thunder Power products ever again. My experience with that company and its products has left better than 80% of the electric flyers at the two e-clubs I belong to with as bad a taste in their mouths as mine. It's the very reason I have taken the time to post on this particular thread. There are many of us out there that have had the same experience with that company.
I closing I will emphatically state that HYPE won't make a product do what it can't.
Mind you, these packs have been pampered all throughout their life as my method of charging is to do so @ 70% of 1C and discharge them at less than 50% their stated "safe" discharge rated as specified by its manufacturer. All my Li-Pos have been treated the same way since first purchased almost three years ago.
While Kokams, TPEs, and others are still serving me well, only the ones failing me are the Thunder Powers. I have three of their packs that refuse to take a charge, and three that are following the same path. No bloating has been observed on any of the failed packs or the ones on their way there.
One more thing, one that to me is of paramount importance. The treatment I received from Thunder Power when I e-mailed them to find a solution to this problem was appaling at best. Their reply simply was "Our product is guaranteed for 60 days, if your packs are older than 60 days they are not covered by the warranty". That reply was typed in ALL CAPS, without regards for grammar, punctuation or spelling. It made the reading a rather annoying experience based on that fact alone, the substance of the message just added to my annoyance.
Calling them over the telephone was worse than reading their reply. It got me nowhere. What I demand from a manufacturer that is willing to print claims on their packs regarding continuous as well as burst discharge rate for their Li-Po packs is HONESTY, not hype. I base my decision to buy a battery pack on the needs for the particular aircraft it will be used in. This particular manufacturer chose to print "Made in U.S.A." on their packs knowing full well the cells are made in Asia not the U.S.A. What other things am I being misled about their Li-Po packs?
I trusted what was printed on the label implicitly. I also trusted their C rating as printed on the labels, and based on that information I chose Thunder Power for some of my models. Those models are now being re-fitted with better battery packs. I can assure everyone that I will never purchase a product from a manufacturer that chooses to non chalantly mislead their clients.
I will never patronize Thunder Power products ever again. My experience with that company and its products has left better than 80% of the electric flyers at the two e-clubs I belong to with as bad a taste in their mouths as mine. It's the very reason I have taken the time to post on this particular thread. There are many of us out there that have had the same experience with that company.
I closing I will emphatically state that HYPE won't make a product do what it can't.
02-19-2006, 11:59 AM
#38
RE: Battery longevity
Qban,
Having read the entire thread of your troubles with TP on RC Groups, I dont really think it applies here and doubt you will find many that have had problems with TP Prolites in our application.
Greg,
CBA plots done by many on RCG and Wattflyer are not all terribly meaningful in this case....first we dont run the pack continuously at 15C...we run it at 5-6C with 10-12C bursts. Second, we dont run them in an enviornment where they will get hot, they are in open airflow in a plane travelling up into 100+ kph. Its a completely unfair test to CBA a pack and allow it to acheive rediculously high temperatures causing failure. All the test indicates is that cooling is going to be required in that case.
Its a well known fact that mass correlates to temperature during discharge, when Kokam releases a 10s 5300 mAh pack that weighs 1000-1100 grams, it will be interesting to compare temps of the cells. My guess is they wont do any better temp wise....not that its a problem in the first place
Well my lot is holding up well, I often check the packs after a discharge just for kicks....usually they are in the 3.780V voltage range and typically the imbalance is <0.005....very often I see my packs with 0.001V imbalance. After a charge the imblance is typically slightly worse than after a discharge.
Produce a light 5000 mAh pack in a nice small package for F3A Right now TP and maybe the new Evo20 packs are about the only real option, everything else is either too small, or too heavy.
Whats even more interesting to me is that you blasted Adam for "touting Thunder Power solutions without any real data" while you are doing the same for Kokam....yet Adam has real data...and you dont.
Having read the entire thread of your troubles with TP on RC Groups, I dont really think it applies here and doubt you will find many that have had problems with TP Prolites in our application.
Here is a single link to the Wattflyer Battery Vault. Look at not just the discharge currents but also the temperatures and summary comparison links. Soon, cycle life data will be posted here and you may be quite shocked.
CBA plots done by many on RCG and Wattflyer are not all terribly meaningful in this case....first we dont run the pack continuously at 15C...we run it at 5-6C with 10-12C bursts. Second, we dont run them in an enviornment where they will get hot, they are in open airflow in a plane travelling up into 100+ kph. Its a completely unfair test to CBA a pack and allow it to acheive rediculously high temperatures causing failure. All the test indicates is that cooling is going to be required in that case.
Its a well known fact that mass correlates to temperature during discharge, when Kokam releases a 10s 5300 mAh pack that weighs 1000-1100 grams, it will be interesting to compare temps of the cells. My guess is they wont do any better temp wise....not that its a problem in the first place
Any one pack or few packs can stay in balance depending upon the use, abuse, handling, and manufacturing lot. The cells all age differently as they are exposed to different criteria like outside handling abuses and inside temperatures. Once this happens, it becomes even more important to safely operate the pack within the limits of the weakest cell
Produce a light 5000 mAh pack in a nice small package for F3A
Right now TP and maybe the new Evo20 packs are about the only real option, everything else is either too small, or too heavy.Whats even more interesting to me is that you blasted Adam for "touting Thunder Power solutions without any real data" while you are doing the same for Kokam....yet Adam has real data...and you dont.
02-19-2006, 06:45 PM
#39
Member
Join Date: Sep 2003
Location: WHEATON,
MD
Posts: 43
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
ORIGINAL: can773
Qban,
Having read the entire thread of your troubles with TP on RC Groups, I dont really think it applies here and doubt you will find many that have had problems with TP Prolites in our application.
Qban,
Having read the entire thread of your troubles with TP on RC Groups, I dont really think it applies here and doubt you will find many that have had problems with TP Prolites in our application.
Whether it happens to deal with high current demands or not makes absolutely no difference, they failed me while they were being pampered.
BTW, I assume the Ignore User option is available here as well as on RCG. You, as well as any others who may wish not to read the truth I have to tell about that company are free to use it and put my user ID in yours. I am as free to post about my woes with Thunder Power products and its management. Especially when they begin by misleading us all about their country of origin. I wonder what other "facts" are we being misled about by Thunder Power on their labels.
I am pleased that you have had such good luck with Thunder Power products and hope you continue to do so. On the other hand I, as well as many others, can't say the same thing for their products, its CEO and customer service department.
02-19-2006, 08:07 PM
#40
My Feedback: (46)
Join Date: Sep 2003
Location: Bridgewater,
NJ
Posts: 948
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
This forum is about peoples experience in pattern, not your personal vendetta. Please refrain from posting your crap on here anymore. I have seen more than my share of it on the other forums, as well, and so have many of the people on this forum, as well. You've made your point now go away.
02-19-2006, 08:41 PM
#41
Member
Join Date: Sep 2003
Location: WHEATON,
MD
Posts: 43
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
Nice try, a failed one, but a try anyway. Title of the thread is: Battery longevity. [8D]
If telling the truth about Thunder Power, its CEO and customer service department is considered a vendetta, then I have a vendetta going against them. BTW, I am not going anywhere anytime soon either.
Title of the thread is: Battery longevity. [8D] If telling the truth about Thunder Power, its CEO and customer service department is considered a vendetta, then I have a vendetta going against them. BTW, I am not going anywhere anytime soon either.
ORIGINAL: jlachow
This forum is about peoples experience in pattern, not your personal vendetta. Please refrain from posting your crap on here anymore. I have seen more than my share of it on the other forums, as well, and so have many of the people on this forum, as well. You've made your point now go away.
This forum is about peoples experience in pattern, not your personal vendetta. Please refrain from posting your crap on here anymore. I have seen more than my share of it on the other forums, as well, and so have many of the people on this forum, as well. You've made your point now go away.
02-19-2006, 08:47 PM
#42
My Feedback: (11)
Join Date: Jul 2003
Location: Tracy,
CA
Posts: 2,080
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
I second that.
Sorry you have had problems with the TP's. That really sucks. I feel for ya. But, this is an electric pattern forum. Yes the thread is about batteries. But it's not in the general electric forum. This thread is for the purpose of pattern folk to learn about what other pattern folk are getting out of their batteries.
Yes, you can post where you want. Just keep to the subject of the thread and all will be fine.
Anyhow, keep em coming. My new Eclipse should test fly tomorrow with tp 5300's. Looking forward to seeing some new battery competition come in with lighter packs in the 4000mah range..
Chris
Sorry you have had problems with the TP's. That really sucks. I feel for ya. But, this is an electric pattern forum. Yes the thread is about batteries. But it's not in the general electric forum. This thread is for the purpose of pattern folk to learn about what other pattern folk are getting out of their batteries.
Yes, you can post where you want. Just keep to the subject of the thread and all will be fine.
Anyhow, keep em coming. My new Eclipse should test fly tomorrow with tp 5300's. Looking forward to seeing some new battery competition come in with lighter packs in the 4000mah range..
Chris
02-19-2006, 09:10 PM
#43
RE: Battery longevity
ORIGINAL: patternflyer1
Anyhow, keep em coming. My new Eclipse should test fly tomorrow with tp 5300's. Looking forward to seeing some new battery competition come in with lighter packs in the 4000mah range..
Chris
Anyhow, keep em coming. My new Eclipse should test fly tomorrow with tp 5300's. Looking forward to seeing some new battery competition come in with lighter packs in the 4000mah range..
Chris
Why not try the 5s2p 4200's? They are a fair bit lighter than the 53's if you are trying to save weight
Just dont go flying P-07 with them LOL You will like the 5300's though, smokin power for their weight
I will try and redo my plot of my packs, I noticed that it is almost unreadable as posted...
02-19-2006, 09:13 PM
#44
My Feedback: (11)
Join Date: Jul 2003
Location: Tracy,
CA
Posts: 2,080
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
Thanks Chad,
I'll look into them. Sucks as I need the nose weight, lol. But yeah, it'd be nice to be able to go to a lighter pack if I go to the nats.
P-07, not yet.
Masters this year..
Same setup as Tom. Except the 5300's
Axi-F3A, Jeti 90.
Looking forward to it..
I'll look into them. Sucks as I need the nose weight, lol. But yeah, it'd be nice to be able to go to a lighter pack if I go to the nats.
P-07, not yet.
Masters this year..
Same setup as Tom. Except the 5300's
Axi-F3A, Jeti 90.
Looking forward to it..
02-20-2006, 08:42 AM
#45
Senior Member
RE: Battery longevity
ExFokkerFlyer,
I agree. I am not condemning the Saehan cells. Please keep in mind that ThunderPower is merely a pack maker and many vendors sell the same Saehan cells. For example, Impact which is distributed by RipMax in the UK.
The Kokam 4800mAh cells are new 20C cells that can deliver 100amps of current. Until recently, FMA Direct did not manufacture big packs due to liability issues which have now been resolved through cell monitoring techniques in the Cellpro and BalancePro HD lines. Recall Steve Neu's column in Quiet Flyer a year ago called, "The Good, the Bad, and the Ugly", which was about pack assembly quality. FMA's Kokam packs were the good and ThunderPower's were the ugly. A quality circuit board with proper strain relief on the discharge wires does add weight but it beats tabs soldered together and wrapped by strapping tape any day.
You can view the life cycle testing charts on RCU in this thread called, [link=http://www.rcuniverse.com/forum/m_3559995/tm.htm]FMA Li Po Pack Life of 452 Cycles at Heavy RC Discharge Rates[/link]. It is obvious that the ThunderPower cells are over-rated.
Several units exist to monitor airborn current draw. I recently reviewed one that was easy to use on any system and simply connected to a USB port on your PC to download the data. You can read the review [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=634]here[/link]. I am glad to see your passion for electric flight!
can773,
I agree. If the pack works for you, I cannot dispute that. The point that I seem to be failing to make is that a 1p solution will be superior to a 3p or 4p solution in general. The weight advantages of a 4p solution are negated and cell monitoring techniques are masked with parallel cells. Please review my links again as they are real data from independent sources. The cycle life data is from Nathan Gwozdecki. The independent sources are still setting up for automated cycle life testing. Nathan Gwozdecki has been doing this for many years now.
Running a pack for testing at 1C is no use at all. The data shown in my links makes it clear that the TP and TANIC packs get very hot, much more than a Kokam in either 3200mAh or 2P10S of the 2000mAh size. We already can show that the KOK 2000 goes 450 cycles while the TP 2100 goes 38 cycles at rated C. Adam states a 5S pack for F3A and at 60 amps he quotes that is only about 1250 watts when we know an F3A has to peak at about 2700 watts and run about 1750 watts average. I question whether Adam has ever flown an F3A airplane or equipped one to test it. I have nothing against Adam, I simply don't understand his point of view or justifications.
Some conclusions at this time:
[ul][*] Thunderpower packs in the application at 2700 watts in a 3P config are drawing a peak of 75 amps or 25 amps/parallel pack. Even with cooling, the pack will reach at least 160 degrees and have a short lifespan. [*] If you run a 1P pack of KOK 3200, it will reach 160 Deg F and have a short cycle life of about 50 cycles. [*] If you run a KOK 2000 10S2P, that is about 35 amps and life cycle will be about 60 cycles.[*] If you run a TANIC pack in 2p, it will go over 175 Deg F and fry in one or two runs.[*] The KOK 3200 in 10S2P does not even warm up, delivers all that is needed in duration, and delivers by far the greatest wattage. The airplane has to be light to carry the 3.66 lb weight. [*] The best pack for 2006 will be, without doubt, the KOK 4.8 AH at 2.5 lb. It will provide everything needed and give life cycle of at least 500 cycles.
[/ul]
Further Observations:
The only reasons that ThunderPower had any success at the competition level even at top class level can be summarized as follows:
[ul][*] ThunderPower was giving away packs[*] All the competitors were converting existing IC designs which were heavy airframes which meant that no KOKAM solution could be offered due to the 5 KILO weight restriction. The ThunderPower solutions were under powered on the vertical maneuvers compared to IC machines.[*] The Patternship manufacturers know nothing about electrics or the art of building an electric airframe light enough but strong enough.[*] A world-class F3A pattern plane draws over 90 amps on the pull up vertical maneuvers with a 10S voltage.[*] At least 4Ah is needed to complete a single schedule with all likely wind conditions, 5AH is preferred for a strong finish.[*] The pilot at this level needs the pack to be stiff during the schedule flight so that there is no power fade, remember these guys at top level are watching that plane like a hawk for the smoothness of flight and when he wants power it must be there immediately. They are judged on the presence of the flight .
[/ul]
I agree. I am not condemning the Saehan cells. Please keep in mind that ThunderPower is merely a pack maker and many vendors sell the same Saehan cells. For example, Impact which is distributed by RipMax in the UK.
The Kokam 4800mAh cells are new 20C cells that can deliver 100amps of current. Until recently, FMA Direct did not manufacture big packs due to liability issues which have now been resolved through cell monitoring techniques in the Cellpro and BalancePro HD lines. Recall Steve Neu's column in Quiet Flyer a year ago called, "The Good, the Bad, and the Ugly", which was about pack assembly quality. FMA's Kokam packs were the good and ThunderPower's were the ugly. A quality circuit board with proper strain relief on the discharge wires does add weight but it beats tabs soldered together and wrapped by strapping tape any day.
You can view the life cycle testing charts on RCU in this thread called, [link=http://www.rcuniverse.com/forum/m_3559995/tm.htm]FMA Li Po Pack Life of 452 Cycles at Heavy RC Discharge Rates[/link]. It is obvious that the ThunderPower cells are over-rated.
Several units exist to monitor airborn current draw. I recently reviewed one that was easy to use on any system and simply connected to a USB port on your PC to download the data. You can read the review [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=634]here[/link]. I am glad to see your passion for electric flight!
can773,
I agree. If the pack works for you, I cannot dispute that. The point that I seem to be failing to make is that a 1p solution will be superior to a 3p or 4p solution in general. The weight advantages of a 4p solution are negated and cell monitoring techniques are masked with parallel cells. Please review my links again as they are real data from independent sources. The cycle life data is from Nathan Gwozdecki. The independent sources are still setting up for automated cycle life testing. Nathan Gwozdecki has been doing this for many years now.
Running a pack for testing at 1C is no use at all. The data shown in my links makes it clear that the TP and TANIC packs get very hot, much more than a Kokam in either 3200mAh or 2P10S of the 2000mAh size. We already can show that the KOK 2000 goes 450 cycles while the TP 2100 goes 38 cycles at rated C. Adam states a 5S pack for F3A and at 60 amps he quotes that is only about 1250 watts when we know an F3A has to peak at about 2700 watts and run about 1750 watts average. I question whether Adam has ever flown an F3A airplane or equipped one to test it. I have nothing against Adam, I simply don't understand his point of view or justifications.
Some conclusions at this time:
[ul][*] Thunderpower packs in the application at 2700 watts in a 3P config are drawing a peak of 75 amps or 25 amps/parallel pack. Even with cooling, the pack will reach at least 160 degrees and have a short lifespan. [*] If you run a 1P pack of KOK 3200, it will reach 160 Deg F and have a short cycle life of about 50 cycles. [*] If you run a KOK 2000 10S2P, that is about 35 amps and life cycle will be about 60 cycles.[*] If you run a TANIC pack in 2p, it will go over 175 Deg F and fry in one or two runs.[*] The KOK 3200 in 10S2P does not even warm up, delivers all that is needed in duration, and delivers by far the greatest wattage. The airplane has to be light to carry the 3.66 lb weight. [*] The best pack for 2006 will be, without doubt, the KOK 4.8 AH at 2.5 lb. It will provide everything needed and give life cycle of at least 500 cycles.
[/ul]
Further Observations:
The only reasons that ThunderPower had any success at the competition level even at top class level can be summarized as follows:
[ul][*] ThunderPower was giving away packs[*] All the competitors were converting existing IC designs which were heavy airframes which meant that no KOKAM solution could be offered due to the 5 KILO weight restriction. The ThunderPower solutions were under powered on the vertical maneuvers compared to IC machines.[*] The Patternship manufacturers know nothing about electrics or the art of building an electric airframe light enough but strong enough.[*] A world-class F3A pattern plane draws over 90 amps on the pull up vertical maneuvers with a 10S voltage.[*] At least 4Ah is needed to complete a single schedule with all likely wind conditions, 5AH is preferred for a strong finish.[*] The pilot at this level needs the pack to be stiff during the schedule flight so that there is no power fade, remember these guys at top level are watching that plane like a hawk for the smoothness of flight and when he wants power it must be there immediately. They are judged on the presence of the flight .
[/ul]
02-20-2006, 09:13 AM
#46
My Feedback: (11)
Join Date: Jul 2003
Location: Tracy,
CA
Posts: 2,080
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
I made it this far
1. All done under carefully controlled lab conditions using precision test equipment.
and decided that the info you provide is already not "real world tests"
Correct me if I'm wrong.
Oh, and its a 3s pack. Give us some real world data on a 10s packs, or at least 5s.
1. All done under carefully controlled lab conditions using precision test equipment.
and decided that the info you provide is already not "real world tests"
Correct me if I'm wrong.
Oh, and its a 3s pack. Give us some real world data on a 10s packs, or at least 5s.
02-20-2006, 11:21 AM
#47
Senior Member
Join Date: Aug 2003
Location: Lugano, SWITZERLAND
Posts: 289
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
can773
Average 5-6C and burst to maybe 12C.
Average 5-6C and burst to maybe 12C.
I have been told once that due to principle of brushless electronic speed controllers, where full current is given in short bursts, batteries should always be chosen for peak current, not mean current: we are, in fact, giving short bursts of full current all of the time. In fact, when running at less than 100% output, the ESC is constantly working between the "off" and "full" positions. This is why it gets hot in our application.
This would somehow put things into a different perspective: being over the maximum rated (allowed) current would mean you are stressing the pack beyond its limits most of the time. Which is why I chose to calibrate my packs (Polyquest 3700XP) to the maximum current on my plane (55A), which is barely inside the mean rated current but surely inside peak rated current.
Regards,
-Fabrizio
02-20-2006, 12:00 PM
#48
RE: Battery longevity
ORIGINAL: Neo02
Hello, sorry to hijack this post, but I would like to ask something.
I have been told once that due to principle of brushless electronic speed controllers, where full current is given in short bursts, batteries should always be chosen for peak current, not mean current: we are, in fact, giving short bursts of full current all of the time. In fact, when running at less than 100% output, the ESC is constantly working between the "off" and "full" positions. This is why it gets hot in our application.
This would somehow put things into a different perspective: being over the maximum rated (allowed) current would mean you are stressing the pack beyond its limits most of the time. Which is why I chose to calibrate my packs (Polyquest 3700XP) to the maximum current on my plane (55A), which is barely inside the mean rated current but surely inside peak rated current.
Regards,
-Fabrizio
can773
Average 5-6C and burst to maybe 12C.
Average 5-6C and burst to maybe 12C.
I have been told once that due to principle of brushless electronic speed controllers, where full current is given in short bursts, batteries should always be chosen for peak current, not mean current: we are, in fact, giving short bursts of full current all of the time. In fact, when running at less than 100% output, the ESC is constantly working between the "off" and "full" positions. This is why it gets hot in our application.
This would somehow put things into a different perspective: being over the maximum rated (allowed) current would mean you are stressing the pack beyond its limits most of the time. Which is why I chose to calibrate my packs (Polyquest 3700XP) to the maximum current on my plane (55A), which is barely inside the mean rated current but surely inside peak rated current.
Regards,
-Fabrizio
Yes you should pick a pack that can provide your max current all the time, so if your static is 70A optimally you want a pack that can do 70A (or close to it) continously.
My 5-6C comment was for Greg trying to explain that we dont run our packs at 15C for the duration of their discharge. A lot of testing is done that does that and companies use these tests for marketing...but its not a very realistic test for our application. To fly for 10 minutes thats an average 6C discharge or thereabouts.
02-20-2006, 12:26 PM
#49
Senior Member
Join Date: Aug 2003
Location: Frederick, MD
Posts: 180
Likes: 0
Received 0 Likes
on
0 Posts
RE: Battery longevity
ORIGINAL: patternflyer1
I made it this far
1. All done under carefully controlled lab conditions using precision test equipment.
and decided that the info you provide is already not "real world tests"
Correct me if I'm wrong.
Oh, and its a 3s pack. Give us some real world data on a 10s packs, or at least 5s.
I made it this far
1. All done under carefully controlled lab conditions using precision test equipment.
and decided that the info you provide is already not "real world tests"
Correct me if I'm wrong.
Oh, and its a 3s pack. Give us some real world data on a 10s packs, or at least 5s.
02-20-2006, 02:03 PM
#50
RE: Battery longevity
Greg,
With all due respect, not to turn this into an argument or even a heated discussion, but I think you might want to have some real world experience in electric pattern before you draw any more conclusions like you have. Based on your last few posts on this thread, I myself have come to a couple conclusions.
One, it's obvious that your company has spent a lot of money running tests on batteries. It is also obvious that you have spent a lot of time poring over that data to better understand how your company should market your product to the masses.
Two, you don't know the first thing about flying pattern with electric power. I read your threads on glow to electric conversions and you have done a lot of neat and innovative things there. I followed along with the Icepoint conversion as well, but the batteries that were chosen, and the motor that was used did not let that airplane reach it's full potential. How many actual pattern flights did you put the Icepoint through? Any contests?
A friend of mine as an Icepoint with a Hacker and TP5300s. When my airplane suffered some damage at a contest, he kindly loaned it to me to finish the contest... I flew i think 5 flights with it, three in front of judges. The power was not even an issue, I never hit full stick, maybe 75% stick on the uplines and that was enough for the speed that I wanted. It's a good honest airplane if you have it set up right, and with Scotts power combination it will do anything asked of it. Underpowered? I think not... here's a video to prove it.
[link=http://media.putfile.com/PoeticMasters]Poetic Masters flight[/link]
As far as your bullet points go... there are so many errors and questions about your conclusions, where to begin?
ThunderPower was giving away packs
I never got any... I realize that TP jumped into the game early and either gave away or severely discounted batteries to those who might be good representative. But I never got a free pack, nor did anybody up here in Norcal who is flying TP in their pattern planes get free batteries. The actual number of people who get free stuff in pattern like batteries, motors, radio equipment is pretty small.
All the competitors were converting existing IC designs which were heavy airframes which meant that no KOKAM solution could be offered due to the 5 KILO weight restriction. The ThunderPower solutions were under powered on the vertical maneuvers compared to IC machines.
If you read the threads here, many of the first conversions were initially overweight because the battery technology was just not quite there yet. Many guys were using 8000 mah packs because the C ratings were so low, but that was a couple generations ago. As far as being underpowered... are you saying that TP solutions are underpowered now as well? If so I invite you to come out here and fly a couple of my setups... If you are saying that they used to be underpowered... okay, I don't think so but i'm going to take a pass on that... Whether a system has enough power or not is not soley dependent on which batteries you are running... Besides, if electrics were so underpowered, why are we seeing so many pattern guys convert?
The Patternship manufacturers know nothing about electrics or the art of building an electric airframe light enough but strong enough.
How many have you built? Most pattern kits consist of foam wings (might be sheeted already) and tail, and a fiberglass/composite fuselage. Most airplanes can be made to make weight, whether they do or not is usually up to the experience level of the builder. Before you ask, yeah mine have been overweight to some degree... the next one built from a kit won't be! There does seem to be a need to reevaluate how an electric pattern plane should be built though... the Oxai/Matt Beryll is a great example of starting from a clean sheet of paper. IMHO
A world-class F3A pattern plane draws over 90 amps on the pull up vertical maneuvers with a 10S voltage.
Absolutely false! Again Greg, where are you getting this information??? My Focus, RIP, with a AXI 5330/F3A and TP 6000 batteries in a 10S would climb out of sight vertically at about 40 amps!!! My wot current draw with the 20x13 prop was about 65 amps... I would fly the verticals in the sequence at roughly 60-70% stick... when you take into consideration the throttle curve... my draw was around 40 amps for most verticals... never any more unless I was showing off. In fact, I test flew another Focus a couple weeks ago. The power was outragous and the verticals (accellerating go up mind you) were done at less than half stick WITH a curve. Actual power was probably a bit less than 40 amps as the plane was lighter than mine.
Most pattern set ups that the guys on here are flying don't even draw 70 amps at WOT. Most people's hearts stop when I tell them what my draw is with the 22-12 prop and it's STILL below your number.
At least 4Ah is needed to complete a single schedule with all likely wind conditions, 5AH is preferred for a strong finish.
Are you saying that you need to draw 4 or 5 amps respectively FROM your packs? Or are you saying that you need at least a battery with a 4 or 5 amp capacity? If it's the latter... that's pretty close, but dependant on the motor prop combination as well. I'm going to get different numbers with my AXI than Chad or Adam get with their Plettenbergs... and those will also be different than what a Hacker guy is going to pull. Again, real world testing would illuminate this. My Focus could do the entire Master's schedule IN WIND for 2500 mah. I had flights in calm conditions of about 2000 mah (must have forgotten a manuever!!!)... that was the exception rather than the rule though. Most draws were in the 22-2400 mah range for a practice contest flight. I couldn't do that with my Plettenberg, nor could I probably do it with my fiends Hacker powered Icepoint (his draws for the same flight vary between 2800 and 3300)... but for whatever reason my set up could do it. So I could use a smaller battery, but I have to because my motor is heavier. But each combination has it's own requirements.
Like I have said before, I do like the features that your batteries are offering. If you have a 4-5ah battery in a 10s config less than 40 ounces, I might buy it... but your lab data, while interesting just doesn't hold any water with me. I know how my batteries act... I know how much draw is required for a given flight and can predict how weather will affect it. I flew over 200 flights in the second half of last year, and I flew 50 flights in a three week period (work has been slow [8D]) this year, and I have learned a lot about to operate this things and what to expect... I continue to learn every day I go out, and when I read up on here about what other people are doing.
There are some guys with a lot more real world experience than me on here... Adam, Chad are just two that have piped in on this thread. I don't agree with everything they say (especially what Chad says! [8D]), but I respect their opinion because their experience is not just from reading a lab report... it's from flying day in and day out practicing for the Nats and the Worlds... or the other guys who do the same for their local contests.
For what it's worth, and I may be out of place saying this... FMA has some good products, but if you are trying to tap into the pattern market, you are going about it the wrong way. Find somebody that flies pattern... I mean actually competes and places well... preferrably a Masters or FAI pilot (though a good Advanced guy would probably work too) and set him up... freebies, deals, whatever... let him put 200 cycles on the batteries and the system and then look over his conclusions... better yet, have a couple guys running different motors as well as that definitely affects how much current draw is required for a given sequence. Make them your reps, ask them to promote your product backed up by their actual experience with said product.
Actual results and conclusions from somebody who is ACTUALLY flying your batteries day in and day out and COMPETING successfully will likely sway more consumers than quoting lab results that are non issues anyway.
I'm sure it didn't come off as well as i would have liked, but I honestly did not, and do not mean to insult, belittle, or degrade your comments and conclusions, they just needed to be corrected.
Respectfully,
Tom Messer
With all due respect, not to turn this into an argument or even a heated discussion, but I think you might want to have some real world experience in electric pattern before you draw any more conclusions like you have. Based on your last few posts on this thread, I myself have come to a couple conclusions.
One, it's obvious that your company has spent a lot of money running tests on batteries. It is also obvious that you have spent a lot of time poring over that data to better understand how your company should market your product to the masses.
Two, you don't know the first thing about flying pattern with electric power. I read your threads on glow to electric conversions and you have done a lot of neat and innovative things there. I followed along with the Icepoint conversion as well, but the batteries that were chosen, and the motor that was used did not let that airplane reach it's full potential. How many actual pattern flights did you put the Icepoint through? Any contests?
A friend of mine as an Icepoint with a Hacker and TP5300s. When my airplane suffered some damage at a contest, he kindly loaned it to me to finish the contest... I flew i think 5 flights with it, three in front of judges. The power was not even an issue, I never hit full stick, maybe 75% stick on the uplines and that was enough for the speed that I wanted. It's a good honest airplane if you have it set up right, and with Scotts power combination it will do anything asked of it. Underpowered? I think not... here's a video to prove it.
[link=http://media.putfile.com/PoeticMasters]Poetic Masters flight[/link]
As far as your bullet points go... there are so many errors and questions about your conclusions, where to begin?
ThunderPower was giving away packs
I never got any... I realize that TP jumped into the game early and either gave away or severely discounted batteries to those who might be good representative. But I never got a free pack, nor did anybody up here in Norcal who is flying TP in their pattern planes get free batteries. The actual number of people who get free stuff in pattern like batteries, motors, radio equipment is pretty small.
All the competitors were converting existing IC designs which were heavy airframes which meant that no KOKAM solution could be offered due to the 5 KILO weight restriction. The ThunderPower solutions were under powered on the vertical maneuvers compared to IC machines.
If you read the threads here, many of the first conversions were initially overweight because the battery technology was just not quite there yet. Many guys were using 8000 mah packs because the C ratings were so low, but that was a couple generations ago. As far as being underpowered... are you saying that TP solutions are underpowered now as well? If so I invite you to come out here and fly a couple of my setups... If you are saying that they used to be underpowered... okay, I don't think so but i'm going to take a pass on that... Whether a system has enough power or not is not soley dependent on which batteries you are running... Besides, if electrics were so underpowered, why are we seeing so many pattern guys convert?
The Patternship manufacturers know nothing about electrics or the art of building an electric airframe light enough but strong enough.
How many have you built? Most pattern kits consist of foam wings (might be sheeted already) and tail, and a fiberglass/composite fuselage. Most airplanes can be made to make weight, whether they do or not is usually up to the experience level of the builder. Before you ask, yeah mine have been overweight to some degree... the next one built from a kit won't be! There does seem to be a need to reevaluate how an electric pattern plane should be built though... the Oxai/Matt Beryll is a great example of starting from a clean sheet of paper. IMHO
A world-class F3A pattern plane draws over 90 amps on the pull up vertical maneuvers with a 10S voltage.
Absolutely false! Again Greg, where are you getting this information??? My Focus, RIP, with a AXI 5330/F3A and TP 6000 batteries in a 10S would climb out of sight vertically at about 40 amps!!! My wot current draw with the 20x13 prop was about 65 amps... I would fly the verticals in the sequence at roughly 60-70% stick... when you take into consideration the throttle curve... my draw was around 40 amps for most verticals... never any more unless I was showing off. In fact, I test flew another Focus a couple weeks ago. The power was outragous and the verticals (accellerating go up mind you) were done at less than half stick WITH a curve. Actual power was probably a bit less than 40 amps as the plane was lighter than mine.
Most pattern set ups that the guys on here are flying don't even draw 70 amps at WOT. Most people's hearts stop when I tell them what my draw is with the 22-12 prop and it's STILL below your number.
At least 4Ah is needed to complete a single schedule with all likely wind conditions, 5AH is preferred for a strong finish.
Are you saying that you need to draw 4 or 5 amps respectively FROM your packs? Or are you saying that you need at least a battery with a 4 or 5 amp capacity? If it's the latter... that's pretty close, but dependant on the motor prop combination as well. I'm going to get different numbers with my AXI than Chad or Adam get with their Plettenbergs... and those will also be different than what a Hacker guy is going to pull. Again, real world testing would illuminate this. My Focus could do the entire Master's schedule IN WIND for 2500 mah. I had flights in calm conditions of about 2000 mah (must have forgotten a manuever!!!)... that was the exception rather than the rule though. Most draws were in the 22-2400 mah range for a practice contest flight. I couldn't do that with my Plettenberg, nor could I probably do it with my fiends Hacker powered Icepoint (his draws for the same flight vary between 2800 and 3300)... but for whatever reason my set up could do it. So I could use a smaller battery, but I have to because my motor is heavier. But each combination has it's own requirements.
Like I have said before, I do like the features that your batteries are offering. If you have a 4-5ah battery in a 10s config less than 40 ounces, I might buy it... but your lab data, while interesting just doesn't hold any water with me. I know how my batteries act... I know how much draw is required for a given flight and can predict how weather will affect it. I flew over 200 flights in the second half of last year, and I flew 50 flights in a three week period (work has been slow [8D]) this year, and I have learned a lot about to operate this things and what to expect... I continue to learn every day I go out, and when I read up on here about what other people are doing.
There are some guys with a lot more real world experience than me on here... Adam, Chad are just two that have piped in on this thread. I don't agree with everything they say (especially what Chad says! [8D]), but I respect their opinion because their experience is not just from reading a lab report... it's from flying day in and day out practicing for the Nats and the Worlds... or the other guys who do the same for their local contests.
For what it's worth, and I may be out of place saying this... FMA has some good products, but if you are trying to tap into the pattern market, you are going about it the wrong way. Find somebody that flies pattern... I mean actually competes and places well... preferrably a Masters or FAI pilot (though a good Advanced guy would probably work too) and set him up... freebies, deals, whatever... let him put 200 cycles on the batteries and the system and then look over his conclusions... better yet, have a couple guys running different motors as well as that definitely affects how much current draw is required for a given sequence. Make them your reps, ask them to promote your product backed up by their actual experience with said product.
Actual results and conclusions from somebody who is ACTUALLY flying your batteries day in and day out and COMPETING successfully will likely sway more consumers than quoting lab results that are non issues anyway.
I'm sure it didn't come off as well as i would have liked, but I honestly did not, and do not mean to insult, belittle, or degrade your comments and conclusions, they just needed to be corrected.
Respectfully,
Tom Messer