A123 Question
08-23-2012, 11:12 AM
#52
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RE: A123 Question
For the naysayers......
One 12 minute flight and probably another 6 or 8 minutes of "on" time, warming it up and pre-flight (also dropped some expo and increased throws before my flight).
Battery #1 - Took 14 minutes to charge at .5amp and took 32Mah
One 12 minute flight and probably another 6 or 8 minutes of "on" time, warming it up and pre-flight (also dropped some expo and increased throws before my flight).
Battery #1 - Took 14 minutes to charge at .5amp and took 32Mah
08-23-2012, 12:11 PM
#55
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RE: A123 Question
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
08-23-2012, 01:57 PM
#56
RE: A123 Question
ORIGINAL: RCP57
Finally getting back into the hobby after two years and the battery technology has changed quite a bit. What is the hot ticket for giant scale airplanes? Need to put some new batteries in my 35% YAK w/da 100 motor. The A123 batteries seem to be the newest technology but has anyone come up with a way to check them? Or do I need to look in another direction like Lithium Ion w/regulators?
Finally getting back into the hobby after two years and the battery technology has changed quite a bit. What is the hot ticket for giant scale airplanes? Need to put some new batteries in my 35% YAK w/da 100 motor. The A123 batteries seem to be the newest technology but has anyone come up with a way to check them? Or do I need to look in another direction like Lithium Ion w/regulators?
08-23-2012, 05:25 PM
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RE: A123 Question
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
08-23-2012, 05:26 PM
#58
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RE: A123 Question
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Battery "B" took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
08-23-2012, 07:24 PM
#59
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RE: A123 Question
ORIGINAL: Taz_Hobbies
Yes, it automatically detects the LiFe batt over the Li-Po and goes into auto mode. It always reads 8.38V when the charge cycle is complete. During charging it is around 7 to 7.5v.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
08-24-2012, 03:06 AM
#60
RE: A123 Question
ORIGINAL: Truckracer
Hmmmmm, seems strange to see any reading at any time higher than 7.2V or two LiFe cells!
ORIGINAL: Taz_Hobbies
Yes, it automatically detects the LiFe batt over the Li-Po and goes into auto mode. It always reads 8.38V when the charge cycle is complete. During charging it is around 7 to 7.5v.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
I think the problem is that the charges cannot properly identify the difference and just catagorizes the batteries as LIxx even though they say they can correctly charge on "Auto" settings.
08-24-2012, 03:12 AM
#61
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RE: A123 Question
ORIGINAL: Luchnia
I manually set my LIFE settings at 6.6 and max cut-off at 7.2. I found the "Auto" functions on some chargers simply do not work correctly. I once overcharged to 8.4 on "Auto" and once I found out, I then discharged the pack and charged back up to LIFE 6.6 with a 7.2 cut-off. Now the charger goes up to 7.2 and charges the battery correctly.
I think the problem is that the charges cannot properly identify the difference and just catagorizes the batteries as LIxx even though they say they can correctly charge on "Auto" settings.
ORIGINAL: Truckracer
Hmmmmm, seems strange to see any reading at any time higher than 7.2V or two LiFe cells!
ORIGINAL: Taz_Hobbies
Yes, it automatically detects the LiFe batt over the Li-Po and goes into auto mode. It always reads 8.38V when the charge cycle is complete. During charging it is around 7 to 7.5v.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
I think the problem is that the charges cannot properly identify the difference and just catagorizes the batteries as LIxx even though they say they can correctly charge on "Auto" settings.
08-24-2012, 04:30 AM
#63
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RE: A123 Question
ORIGINAL: Luchnia
I manually set my LIFE settings at 6.6 and max cut-off at 7.2. I found the "Auto" functions on some chargers simply do not work correctly. I once overcharged to 8.4 on "Auto" and once I found out, I then discharged the pack and charged back up to LIFE 6.6 with a 7.2 cut-off. Now the charger goes up to 7.2 and charges the battery correctly.
I think the problem is that the charges cannot properly identify the difference and just catagorizes the batteries as LIxx even though they say they can correctly charge on "Auto" settings.
ORIGINAL: Truckracer
You were 100% correct. The charger did NOT automatically switch and it did indeed over volt / charge the batts. When i said it normally shows 8.38V I was mistaken. I went back thru my charge logs and it has read as high as 7.28V previously. The .38 looked familiar but i was wrong.
Now the question is, did the batteries get damaged?
I am cycling them now and found out how to manually set the 6.6v LiFe settings for my packs. Damn.... I sure may have screwed the pooch on that last charge.
Thanks for bring it up.
Hmmmmm, seems strange to see any reading at any time higher than 7.2V or two LiFe cells!
ORIGINAL: Taz_Hobbies
Yes, it automatically detects the LiFe batt over the Li-Po and goes into auto mode. It always reads 8.38V when the charge cycle is complete. During charging it is around 7 to 7.5v.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
Now the question is, did the batteries get damaged?
I am cycling them now and found out how to manually set the 6.6v LiFe settings for my packs. Damn.... I sure may have screwed the pooch on that last charge.
Thanks for bring it up.
Hmmmmm, seems strange to see any reading at any time higher than 7.2V or two LiFe cells!
I think the problem is that the charges cannot properly identify the difference and just catagorizes the batteries as LIxx even though they say they can correctly charge on "Auto" settings.
08-24-2012, 08:02 AM
#64
RE: A123 Question
From the expert Iwouldnot use just any old charger. Only a charger that is rated for A123/ LiFe batterys
http://www.hangtimes.com/a123_batter...iants_faq.htmlQ: Can I use my ‘XYZ’ brand NiCad /NiMH charger or Wall Wart on LiFe?
*
No. Let me be specific… HELL NO! Here’s what’s going on.. LiFe’s nominal voltage per cell is 3.3v. While the charge routine is similar to LiIon or LiPoly, the max allowable voltage under charge is lower than any other Lithium technology cell, usually about 3.6v; so using a standard LiIon or LiPoly charger will do damage. For you NiCad -NiMH guys, the entire charge sub-routine is different . As of now, there are a number of LiFe capable superchargers coming into the marketplace.. these will deal with ‘em as well as the various other types of Lithium and NiCad/NiMH packs but assume my first answer of HELL NO applies until you review your chargers manual. If you not sure, contact the charger mfg or distributor. Don’t let ‘em blow smoke up your backside either. Get it in writing if it’s not called out in the manual.
ORIGINAL: Truckracer
Dan,
Any decent charger that has a cycle / discharge function will work for the A123 / LiFe batteries as long as the discharge current and cut-off voltage can be set by the user. I prefer to use a manual mode, note the capacity then proceed with a normal charge after that. Note for measuring battery capacity you're only measuring voltage at a specific current / time so the device isn't battery chemistry dependent. Even an old NiCd / NiMh device would work well for this purpose as long as it meets the basic requirements.
So far after over 2.5 years of use my A123 batteries are not showing any loss of capacity. Very unlike Ni chemistry batteries that show some loss of capacity from the day they are put in use forward.
I'm an old guy compared to most here but no dang antique 8 track players for me! Also no voltage regulators ..... never used one, never needed one and never wanted one!
ORIGINAL: All Day Dan
Thanks Andy and everyone else. No one had mentioned cycling A123 batteries before to determine their capacity so it was hard to tell if it could be done. Are there any cyclers out there? Do you just cycle the entire pack or do you have to monitor the individual cells? Do they last two or more years before they get to 80% of their capacity? Dan.
Thanks Andy and everyone else. No one had mentioned cycling A123 batteries before to determine their capacity so it was hard to tell if it could be done. Are there any cyclers out there? Do you just cycle the entire pack or do you have to monitor the individual cells? Do they last two or more years before they get to 80% of their capacity? Dan.
Any decent charger that has a cycle / discharge function will work for the A123 / LiFe batteries as long as the discharge current and cut-off voltage can be set by the user. I prefer to use a manual mode, note the capacity then proceed with a normal charge after that. Note for measuring battery capacity you're only measuring voltage at a specific current / time so the device isn't battery chemistry dependent. Even an old NiCd / NiMh device would work well for this purpose as long as it meets the basic requirements.
So far after over 2.5 years of use my A123 batteries are not showing any loss of capacity. Very unlike Ni chemistry batteries that show some loss of capacity from the day they are put in use forward.
I'm an old guy compared to most here but no dang antique 8 track players for me! Also no voltage regulators ..... never used one, never needed one and never wanted one!
08-24-2012, 08:28 AM
#65
RE: A123 Question
1. Non Balancing 'smart chargers' and the myth that A123's 'don't need balancing'.A close tofully charged pack, deeply discharged pack or out of balance packmay be easily mis-identified by a 'smart'charger WITH THE WRONG CELL COUNT. The results are usually always a ruined pack. If a qualitybalancing charger is used and correctly connected, the charger will see the individual cell voltages in the pack, correctly identify it's cell count and usually report on the individual cell voltages all the way through the charge routine. If 'smart' means stabbing a button and waiting for a green light... well; that mightnot be an appropriate charger for a critical application battery pack.
ORIGINAL: Taz_Hobbies
Yes, it automatically detects the LiFe batt over the Li-Po and goes into auto mode. It always reads 8.38V when the charge cycle is complete. During charging it is around 7 to 7.5v.
Battery "B" took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Battery "B" took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
08-24-2012, 08:30 AM
#66
RE: A123 Question
[quote]ORIGINAL: Taz_Hobbies
ORIGINAL: Luchnia
ORIGINAL: Truckracer
You were 100% correct. The charger did NOT automatically switch and it did indeed over volt / charge the batts. When i said it normally shows 8.38V I was mistaken. I went back thru my charge logs and it has read as high as 7.28V previously. The .38 looked familiar but i was wrong.
Now the question is, did the batteries get damaged?
I am cycling them now and found out how to manually set the 6.6v LiFe settings for my packs. Damn.... I sure may have screwed the pooch on that last charge.
Thanks for bring it up.
Hmmmmm, seems strange to see any reading at any time higher than 7.2V or two LiFe cells!
ORIGINAL: Taz_Hobbies
Yes, it automatically detects the LiFe batt over the Li-Po and goes into auto mode. It always reads 8.38V when the charge cycle is complete. During charging it is around 7 to 7.5v.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
ORIGINAL: Truckracer
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Taz, I don't question your findings and the capacity used out of the battery on each flight .... .but I certainly do question that voltage reading on your charger! That is in line with a fully charged two cell LiPo, not a LiFe battery! Are you sure your charger is operating in the LiFe mode? I would expect to see 7.2 V on the display at the end of a LiFe charge cycle.
Battery ''B'' took 23Mah earlier but I got sidetracked and forgot to snap a photo. It also read 8.38v.
Now the question is, did the batteries get damaged?
I am cycling them now and found out how to manually set the 6.6v LiFe settings for my packs. Damn.... I sure may have screwed the pooch on that last charge.
Thanks for bring it up.
Hmmmmm, seems strange to see any reading at any time higher than 7.2V or two LiFe cells!
I did do a couple of discharges to bring it down to around 5-6 volts and then re-charge and balance and all seems ok. I am thinking about working the battery on the bench some as if in flight, then charging again on minimal charge.
08-24-2012, 09:33 AM
#67
RE: A123 Question
I wonder about balancing. If I set my charger to 1-2 amps and also to balance mode it seems to balance the batteries very quickly. Within about 10 minutes a pack is balanced. Is that normal? I am guessing that the packs are close and balancing may not take long.
Also, I am only pulling about 289-300 MAH out of four flights the last two times out to the field. That calculates out to around 75 mah per flight. Doesn't that seem low? From what everyone else was showing it should be more around 150-200 per flight. I tested this on two planes and both were running almost the same. The most mah I have drawn so far is around 100mah in a flight.
The last test I did was took both planes and flew them both four times each and both tested around 300 mah for all four flights. To me this is ridiculously good. At that rate on a 2500 mah pack I could safely fly 6 flights and not bat an eye to bother with charging. I would only be drawing around 400-600 mah for six flights.
I plan to test my 50cc before too long to see how much it uses. It would be nice if there was a slick way to bench test these A123 batteries. If we had something that could load the battery somewhat comparible to a plane in flight and then re-charge would sure make it easier to determine a baseline. There may be some tools to do that but nothing I am aware of. I suppose I get set a dummy setup up and use some servos on a receiver and emulate it to some degree.
Also, I am only pulling about 289-300 MAH out of four flights the last two times out to the field. That calculates out to around 75 mah per flight. Doesn't that seem low? From what everyone else was showing it should be more around 150-200 per flight. I tested this on two planes and both were running almost the same. The most mah I have drawn so far is around 100mah in a flight.
The last test I did was took both planes and flew them both four times each and both tested around 300 mah for all four flights. To me this is ridiculously good. At that rate on a 2500 mah pack I could safely fly 6 flights and not bat an eye to bother with charging. I would only be drawing around 400-600 mah for six flights.
I plan to test my 50cc before too long to see how much it uses. It would be nice if there was a slick way to bench test these A123 batteries. If we had something that could load the battery somewhat comparible to a plane in flight and then re-charge would sure make it easier to determine a baseline. There may be some tools to do that but nothing I am aware of. I suppose I get set a dummy setup up and use some servos on a receiver and emulate it to some degree.
08-24-2012, 03:11 PM
#69
RE: A123 Question
ORIGINAL: BarracudaHockey
That seems like very VERY low consumption to me
That seems like very VERY low consumption to me
08-24-2012, 04:42 PM
#70
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RE: A123 Question
Luchnia -
Pardon a rookie for "chiming in" - you didn't specify the plane, servos or flight times in your comment about low energy consumption. For example, I'm using a 2300 mah A123 battery in a 5 lb 11 oz U Can Do with Futaba S3152 digital servos (89 oz/in torque) that I fly aggressively - 8 minute flights. My average consumption is about 95 ma per flight. My 8 lb 10 oz Venus pattern plane equipped with the same battery and servos uses about 120 ma per 8-minute flight practicing the Sportsman pattern (very unaggressive flying).
Can you use these examples for a comparison?
Jack
Pardon a rookie for "chiming in" - you didn't specify the plane, servos or flight times in your comment about low energy consumption. For example, I'm using a 2300 mah A123 battery in a 5 lb 11 oz U Can Do with Futaba S3152 digital servos (89 oz/in torque) that I fly aggressively - 8 minute flights. My average consumption is about 95 ma per flight. My 8 lb 10 oz Venus pattern plane equipped with the same battery and servos uses about 120 ma per 8-minute flight practicing the Sportsman pattern (very unaggressive flying).
Can you use these examples for a comparison?
Jack
08-24-2012, 05:11 PM
#71
RE: A123 Question
I am not sure of the exact weight of the planes, but one 30cc gasser has 200 oz Titanium Gear servo on rudder and the rest are digitals that run around 130-150 oz. Flight times are set at ten minutes and I fly the full ten the majority of the time. One NIMH battery for ignition and one A123 2500MAH on receiver. The other plane has Hitec digitals all around. I think they are 5945MG or something along those lines.
I use two servos on elevators, two on ailerons, one on rudder, and one on throttle. I use opto kills for ignitions. My flying is not overly aggressive, yet I will do some snaps, and some other wild stuff. I will do knife edges, loops, rolls, etc., some light duty hovering for a very short time as I am not experienced with that yet.
I use two servos on elevators, two on ailerons, one on rudder, and one on throttle. I use opto kills for ignitions. My flying is not overly aggressive, yet I will do some snaps, and some other wild stuff. I will do knife edges, loops, rolls, etc., some light duty hovering for a very short time as I am not experienced with that yet.
08-28-2012, 06:34 AM
#73
RE: A123 Question
20 cc profile 15kg digitals = 150 to 200 mah per ten min flight
26cc 1/4 scale pitts 15kg digitals = 150 to 200 mah per ten minute flight
30cc 26% yak 15 kg digitals = 150 to 200 mah per ten minute flight
All on genuine a123 2300mah homebuilt packs, pretty consistent power consumption, if after a days flying I found I had to put far more or less into one of these packs I would investigate as it is probably a warning that something is amiss.
09-01-2012, 08:13 PM
#74
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RE: A123 Question
How about another A123 question..
I have a set of 2s A123 packs that have just 3 wires coming out, the power leads and a single lead.. How can I hook these up to my Hitec X2, as it requires (For charging LIPo, LiFe and Li-ion packs) power leads, as well as a Balance plug.. is where a way for me to make an adapter that would essentially give me what I need without having to take the shrink wrap off of the packs, and completely rewiring it?
Thanks, Craig.
I have a set of 2s A123 packs that have just 3 wires coming out, the power leads and a single lead.. How can I hook these up to my Hitec X2, as it requires (For charging LIPo, LiFe and Li-ion packs) power leads, as well as a Balance plug.. is where a way for me to make an adapter that would essentially give me what I need without having to take the shrink wrap off of the packs, and completely rewiring it?
Thanks, Craig.