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RE: Battery longevity - 2/22/2006 5:30:36 PM   
can773



Posts: 1642
Joined: 1/25/2002
From: Calgary, AB, CANADA
Status: online
quote:

ORIGINAL: sc204

10 of these cells would weigh about 40.5 oz. I guess a pack (or 2 5S's) will be a bit heavier with wiring, wrapping etc. If their advertising of cycle life of > 500 cycles was a reality at the discharge rates that we use then I would suspect that they would take over market share in the pattern community. Tom is right however that most of us would need to see a track record or a guarantee of so many cycles before spending that much money on an untested product.

Stuart C.


That cycle life is very likely at only 1C discharge....pretty much the norm for just about any pack today.

To equate (roughly) to running a YS 140/160DZ you only need about 175-200 cycles out of a pack. Tom is starting to get pretty close to that with his 6000's.

Unfortunately it takes forever to get real life results....4 packs at 200 cycles each is 800 flights Thats a lot of flying, nearly 2 flights a day for an entire year!


_____________________________

Chad Northeast

(in reply to sc204)
       Post #: 76

RE: Battery longevity - 2/22/2006 8:10:43 PM   
Big Owdlad


 

Posts: 10
Joined: 6/25/2003
From: Sheffield England
Status: offline
quote:

ORIGINAL: Malcolm H

Sam (Owdlad),

In case you have forgotten you were not the only person competing in F3A iwith an electric model in England last year. Both Steve Burgess and I flew with our Hacker, Flightpower setups in both GBRCAA comps and in the Home International Champs. We also competed in every Scottish F3A contest.

Your Lazulite was impressive, especially in that the battery was cool after a flight BUT I still believe my Hacker setup had it beat in terms of ultimate performance and that was using last years Flightpower Pro 10s3p 6300 mAhr cells which were acknowledged to have poorer voltage stability under load than any of the current best cells. I was pulling 74A on 21 x 14 APCE but can't tell you the voltage and as you know the performance was excellent.

I am about to change to Thunderpower cells to enjoy the weight saving and better voltage stability in a new model but the existing setup was more than competitive. I must also state that I have bought every piece of modelling equipment I have ever used including my batteries.

For the record Sam you really should declare that you are a Kokam sponsored pilot. I'm not suggesting that you would allow this to interfere with the excellent input that you put into this, the GBRCAA and other forums but at least let people have all the facts.

Kind regards

Malcolm Harris


Malcolm

Firstly I said England.

Scotland is part of the United Kingdom, The Jocks have their own SAA competition circuit as well you know . I can't recall Steve flying Electric in England. Yes, I know your a member of the GBRCAA but, the only Comp i can recall you entered was virtually the last one of the season in the good old Republic of Owdlad Land when I had my Lazulite written off ! This couldn't be really classed as a comp

The triple crown (home International) was held on the Isle on Man(Not in England)

Secondly

I do Fly Demo for Aurorra as Mike Redmond is my good friend.

When I Decided to Switch to Electric F3a. Aurorra made it perfectly clear that I wouldn't receive any form of sponsorship, the reason being it sends out the wrong signal to the end user.



Speaking from experience (Flying on the Electric Demo Circuit) The batteries that stood head and shoulders above the rest were, Kokam. I chose Kokam over Thunderpower & Flightpower because I believed that they are the only packs "Fit for Purpose"

I AM NOT A SPONSORED PILOT. But I do have access to test equipment that gives me the ability to make the correct choice of Motor / Prop combination

Performance wise, I thought your Impact looked (appeared) to be struggling for power over the top of the manoeuvres but, that could have been your style of flying (no offence).

When you saw Lazulite fly you was heard to comment "I don't believe it! Sam's done everything opposite to everybody else and yet it works, If not better than everybody else's"


Hope to see you up in good old Sunny Scotland this year for a good old chin wag

Sam

< Message edited by Big Owdlad -- 2/22/2006 8:40:54 PM >

(in reply to Malcolm H)
       Post #: 77

RE: Battery longevity - 2/22/2006 8:33:13 PM   
Big Owdlad


 

Posts: 10
Joined: 6/25/2003
From: Sheffield England
Status: offline
quote:

ORIGINAL: ExFokkerFlyer



I have been on here touting AXI motors and how much power they have, and how little they cost etc... (and I paid for all mine, small discount that covered shipping costs but very much appreciated) and seriously, how many guys out there have tried them or switched over? Not many... and that's okay, you'll all learn!

Now, if somebody who competed in the FAI or even Masters finals at the Nats last year came out and said the same thing... wouldn't it sink in just a little deeper?

Tom


I Concur

Ive tried Pletts(Blew up) Although they are well Engineered, they are overrated & overpriced

Big Owdlad


(in reply to ExFokkerFlyer)
       Post #: 78

RE: Battery longevity - 2/22/2006 10:26:31 PM   
B-snap-roll



Posts: 9
Joined: 6/18/2003
From: Koolskamp, BELGIUM
Status: offline 		Hi guys !

I've read lots off intresting things... and some less intresting things
Just want to share my experiences with you, I'm a F3A / F3M contest pilot in Belgium, not (yet) in the team, I hope very soon ! I pay for all my equipment, just try to get some intresting prices from distributors.
I have flown OS 2 stroke (140 / 160), YS 4 stroke (140L) and last year I've changed to electric, I flew a ZN Line Oxalys with a Hacker C50XL13 and an Acro90 controller.
I've bought 4 packs 4400 mAh from Tara, a Belgian manufacturer, they were OK, after about 40/50 flights I've borrowed a TP5300 pack from JP Zardini to make a flight... The Tara packs had lost a lot of capacity after +/-45 flights (I have no exact specs). I've ordered 2 TP packs, a 4000 and a 5300 which I flew from september untill now, power is great !!!, incredible, I'm almost never at full throttle, only in verticals in very windy conditions ... The weight of my Oxalys with the 4000 pack is about 4.400 gram ready to fly and about 4.630 with the 5300 pack. Power is really no problem, no idea about consumption. The 4000 is perfect for nice weather conditions but limit for windy conditions, so for contests I prefer to take no risks and fly the 5300, I will fly these this year (ordered 3 new packs which should arrive very soon).
JP Zardini flies the Cyclon motor, as he flies bigger and faster than I do, he needs 5300 packs, the 4000 pack is not enough !!!

Right now I'm finishing a second Oxalys for an electric motor, I have a second Hacker and also a Cyclon but don't know what to put in this plane... ?!
building report here : http://www.docinsane.com/component/option,com_forum/Itemid,29/page,viewtopic/t,188/

To get back to the topic, the "cheaper" batteries I've bought were going down after about 40 flights, also lots of inbalance between cells, now I have only about 20 flights with the TP batteries, and no difference between the cells, no lose of power untill now. Philippe Marquet and Christiaan Hans, Belgian team members have over 100 flights with their TP packs and they did'n notice any difference ! My choice for 2006 is made, Thunder Power


(in reply to Big Owdlad)
       Post #: 79

RE: Battery longevity - 2/22/2006 11:03:13 PM   
can773



Posts: 1642
Joined: 1/25/2002
From: Calgary, AB, CANADA
Status: online
quote:

ORIGINAL: Big Owdlad


quote:

ORIGINAL: ExFokkerFlyer



I have been on here touting AXI motors and how much power they have, and how little they cost etc... (and I paid for all mine, small discount that covered shipping costs but very much appreciated) and seriously, how many guys out there have tried them or switched over? Not many... and that's okay, you'll all learn!

Now, if somebody who competed in the FAI or even Masters finals at the Nats last year came out and said the same thing... wouldn't it sink in just a little deeper?

Tom


I Concur

Ive tried Pletts(Blew up) Although they are well Engineered, they are overrated & overpriced

Big Owdlad




No generalizations in that statement

There are many who have great success with them, never blown them up (that would be operator error in my opinion....and goes for any electric motor)....if you were running it at 90A I can understand why...you have to learn to run the equipment within the specs it was designed to run.



_____________________________

Chad Northeast

(in reply to Big Owdlad)
       Post #: 80

RE: Battery longevity - 2/23/2006 10:04:45 AM   
Magne


 

Posts: 333
Joined: 3/7/2004
From: Moss, NORWAY
Status: offline 		Hello.
I also have some comments, opinions and questions.
I have been flying electric pattern the last two seasons (2004/2005), a total of approx. 300 flights, mainly TP 6000, but also some Irate 4400 and E-tec 5100.

First of all, I think it is very good that there is an increasing choice for the consumers. Competition between the various manufacturers is always beneficial for the end user, this will increase the quality of the products, as well as lower the prices in the long run. (The latter is much needed.)

Secondly, I see that there is a lot of focus on what is the required battery capacity. In competition, I have never exceeded 4000 mAh drain, so from this point of view, I think any capacity from 4800 mAh is sufficient. (For ME, with my flying style, model weight etc.)
However, 80-90% of all my flights are not competition flights, but practice flights, and for practicing, I think it is much better to have a higher capacity than just enough to take you through the schedule once.
Take an OS 140 as an example. Many people fly this engine with a 20 or 24 oz. tank, while a tank capacity of 12-14 oz. probably would be sufficient to get through the schedule. The larger tank capacity allows them to fly longer, and therefore get more practice time. Some fly through the schedule twice!! (Because they CAN, not because they have to.)
Why would I not want this also for an electric model?

From what I can see, Thunder Power is currently the manufacturer that offers the highest energy density. (Capacity per kg. or lbs.) My TP 6000 batteries weigh 200g less than my E-tec 5100, and allow me to fly 2 minutes longer.

I build my own models, and can therefore control the weight. My current model weighs 4800g (10 lbs 9 oz.). I currently have two sets of TP6000, and for the coming season I will purchase two more battery sets. Based on two years experience I have concluded that for practical flying, you need 4 sets of batteries and two chargers. In competition I usually fly all rounds with only one pack, charging between flights. Only rarely have I needed to take out a second pack.
I am however considering whether the two next packs actually should be TP8000 packs.
These packs weigh approx. 400g more than the 6000’s, and would take the model weight to 5200g, i.e. not competition legal. But would this matter much, as long as I still have two competition legal packs? The weight increase of 400g would still be much less than the weight difference between a full/empty 24 oz. tank. (Many people flying glow have a take off weight of close to 5500 gram.)
Power would certainly not be a problem, even at this weight. (I use one Hacker C50 and one Cyclon F3A.)

Please comment.

Regards,
Magne

(in reply to can773)
       Post #: 81

RE: Battery longevity - 2/23/2006 12:21:56 PM   
Malcolm H



Posts: 274
Joined: 10/24/2002
From: glasgow, UNITED KINGDOM
Status: offline 		Magne,

Your comments re duration agree with my own thoughts. It is definitely an advantage when practicing to be able to re-fly some of the figures while the errors are still fresh. I am in the process of going Thunderpower which will reduce my capacity from 6300 to 5300mAhr and I must admit I don't relish the reduction in duration.

I hadn't actually thought about practicing at a different model weight than in competition but your point about IC weight changes is valid.

I might ballast up my model and fly it back to back without ballast to see if the difference is noticeable.

Congrats on the new model BTW it looks great.

Regards

Malcolm

(in reply to Magne)
       Post #: 82

RE: Battery longevity - 2/23/2006 12:36:23 PM   
B-snap-roll



Posts: 9
Joined: 6/18/2003
From: Koolskamp, BELGIUM
Status: offline 		I think you have to be a damned good pilot to fly a plane at 5200 gramm in training and then fly it at 4800 gramm on competition. I already feel a huge difference in flying between the 4000 and the 5300 mAh packs. I believe you should fly the same combination in training and competition flights. Also if you have 4 flight packs and 2 chargers why try to fly 2 schedules with one pack, just change packs in between schedules, with 4 packs the first one will be charged when the last one is empty.... if you take the time to let your equipment cool down a bit between flights. A collegue contest pilot blew at least 5 batteries and 3 Hacker motors last year.... reason ? Some people think that flying electric is just charging batteries and flying without anything more. Wrong, I believe flying electric is even more delicate than flying gas, you need to check batteries, let equipment cool down, grease the gear (only if you have a geared motor of course ) after x flights (I do it every 50 flights - takes 20 minutes), etc etc.
Well this guy had about 10 battery packs and just flew one flight after the other... So I think its better to do shorter flights, 1 schedule and maybe 2 or 3 figures, land, wait 10 minutes to let the motor cool down and do another flight.
I agree with you that power is not a problem but you should try the same plane with take of weight of +/- 4400 gramm.... I can assure you you'll feel a huge difference !!!

What's your opinion about power between the Hacker and the Cyclon ??
I fly an Oxalys with the Hacker now but for my second Oxalys, I have one of each, don't know what to put in...
I love the sound of outrunner, but have the impression that the outrunners have less power ?!

regards,
Bert

(in reply to Magne)
       Post #: 83

RE: Battery longevity - 2/24/2006 4:34:48 AM   
Highway 101


 

Posts: 17
Joined: 9/15/2005
From: Del Mar, CA, USA
Status: offline 		Dear Pattern Gurus,
With some trepidation I will make my first post on this forum. It is not strictly a pattern question but pertains to the battery thread. I am building a 3D/ Freestyle 68' Yak powered by a Plett xtra 30-10. I am starting with a 22x10 prop and based on info from this and other foruns will be pulling around 60-65 Amps max. If the claims of the makers are true, the new 20C/30C packs can supply this current easily from a 3700ma pack (Duralite Evo 20 for example). A 10s1p 3700ma pack would weigh under a kilo (988g). If I limited my flight times to 80% of the capacity of the pack (as determined by testing) is there any reason such a set-up wouldn't work? Obviously flight time would be limited compared to the 5300-8000ma solutions which have been discussed in the thread, but I'm flying for fun and not in competition. The lower wing loading would be nice! It is obviously a big leap of faith that the new batteries will deliver the high currents they advertise, but if it is so it seems to allow us to get high current flow without big battery packs.
I enjoy the erudition and experience of the contributors to this forum and look forward to continuing to learn from you all. Cheers,

Mike

(in reply to B-snap-roll)
       Post #: 84

RE: Battery longevity - 2/24/2006 6:24:18 AM   
Adamg-RCU



Posts: 722
Joined: 4/22/2003
From: Saskatoon, SK, CANADA
Status: offline 		Mike, that combination should fly the plane great. I think it is safe to guess that no one has put that power system together, so we're making predictions and assumptions. The best data will be from someone with a bunch of cycles on that exact pack in a power system similar in current draw and throttle usage to yours.

A few numbers and equations
TP 5s4p 5300mAh 560g $275US
Duralite Flight Power Evo 20C 5s1p 3700mAh 494g $210US

TP: 9.5Ah per kg
Evo: 7.5Ah per kg

TP: $52 per Ah
Evo: $57 per Ah

-Adam
Student by winter, Draganfly employee in my spare time, pilot by summer

(in reply to Highway 101)
       Post #: 85

RE: Battery longevity - 2/26/2006 11:53:31 AM   
Big Owdlad


 

Posts: 10
Joined: 6/25/2003
From: Sheffield England
Status: offline 		Battery longevity?

We have a saying in Yorkshire (England) "You don't get owt for nowt." (You don't get something for nothing.)

Why is it that some LiPo cells are lighter than others yet are purportedly better than the heavier cells?

I would like to think the heavier cells have more energy density than the lighter cells consequently they are able to supply more power likewise they should last longer

please enlighten me

Sam

(in reply to Adamg-RCU)
       Post #: 86

RE: Battery longevity - 2/27/2006 4:19:31 AM   
patternflyer1



Posts: 1250
Joined: 7/3/2003
From: Tracy, CA, USA
Status: offline