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Jul 22, 2012, 05:19 AM
Registered User
https://www.rcgroups.com/forums/show...30&postcount=9
Quote:
Originally Posted by GreenAce92_v2 View Post
Know of anyone who fixes batteries?
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Jul 24, 2012, 09:48 AM
PEMAC
SleepySean's Avatar
Quote:
Originally Posted by REVOJohn View Post
yes true but definitly the pack life expectancy would be exponentially decayed
Although I agree this is likely the case, and charge at 1C myself, I haven't been able to find any definitive tests that show it does reduce battery life. I went to parallel charging just to be on the safe side.
Jul 25, 2012, 08:58 AM
REVOJohn's Avatar
Quote:
Originally Posted by SleepySean View Post
Although I agree this is likely the case, and charge at 1C myself, I haven't been able to find any definitive tests that show it does reduce battery life. I went to parallel charging just to be on the safe side.
Hey Sean. No need to look for evidence on the internet.
That's what I do for a living, battery design and qualification for large OEMS.
Faster you charge, faster they die.

We've just designed a battery for 10C charger, 20C discharge at 10,000 cycles...took us 4 years to do it but its done in both LiFEPO4 and LiCobolt.
Although you can charge fast....the charging paramaters again must change in order to compensate for the extra heat
Jul 29, 2012, 07:56 AM
Euphoric flights
GreenAce92_v2's Avatar
Hello.

I'd like to convert the balancer plug on my brand new Thunder Power battery.

Attached is a picture below. Can anyone tell me with confidence which wire will go where? Color to color / color to number of wire from left to right.

I am comfortable with proper soldering and insulating without touching / shorting the cells. I am however uncomfortable with being certain which wire is correct as I recall the balance plugs are backwards in some way or another.

Any help would be appreciated.
Jul 29, 2012, 08:02 AM
Space Coast USA
hoppy's Avatar
Quote:
Originally Posted by GreenAce92_v2 View Post
Hello.

I'd like to convert the balancer plug on my brand new Thunder Power battery.

Attached is a picture below. Can anyone tell me with confidence which wire will go where? Color to color / color to number of wire from left to right.

I am comfortable with proper soldering and insulating without touching / shorting the cells. I am however uncomfortable with being certain which wire is correct as I recall the balance plugs are backwards in some way or another.

Any help would be appreciated.
See post #2 The Hows and Whys of Pack Balancing:
One of the references gives all the different balance connector wiring.
Jul 29, 2012, 08:21 AM
Euphoric flights
GreenAce92_v2's Avatar
Dear God they really need to make that more user friendly.
I appreciate the information but it seems to be just "thrown" there.
It's like the difference between an Apple and Android product

Isn't it not as easy as a ground, 3.7v, 7.4v, 11.1v ?

So if I follow the same for the other adapter then I would be alright?

Here's an image for clarification on my assumption without testing voltage. The T-pro data I found on the balancer page.

Maybe the whole reversed issue is simply the plug being "flipped over" in relation to other plug. I would assume that the pins follow a standard "ground to last wire" = " lowest to highest voltage" right?
Last edited by GreenAce92_v2; Jul 29, 2012 at 08:42 AM.
Jul 29, 2012, 11:48 AM
RC Helicopter Pilot
TheWoodCrafter's Avatar
The JST -XT plug is backwards.
Should be Positive, 3.7, 7.4, 11.1V bottom to top in you drawing.
The TP plug is correct.
Jul 29, 2012, 02:51 PM
Euphoric flights
GreenAce92_v2's Avatar
I see, I couldn't test it, you are sure that that is the way? I created the physical plug based on the male plug itself though I guessed at the voltage placement.

However I did cut the outer ends to run my Vtx's which require 12V's to operate ( around there )

How can it be what you describe? ( not disagreeing ) curious is all.

Thanks for your time.
Jul 29, 2012, 03:04 PM
Space Coast USA
hoppy's Avatar
The JST plug is correct as shown in Greenaces figure.. All my HK/GensAce'Billowy packs use this connector.
With the prongs up as shown...
Black = ground
#2 (white)
#3 (blue)
#4 11.1V (red)

I assume you are going to charge these with a non-TP charger.
Last edited by hoppy; Jul 29, 2012 at 03:15 PM.
Jul 29, 2012, 08:06 PM
RC Helicopter Pilot
TheWoodCrafter's Avatar
I guess what we all describe is the same thing.

It all depends where you measure voltage from, the ground stationary and move the red lead or leave the red lead stationary and move the ground.
Jul 30, 2012, 12:46 AM
Euphoric flights
GreenAce92_v2's Avatar
Yeah it's that whole backwards thing. Electrons flow from the negative terminal haha weird right?

Thanks for the clarification, figured it's about time I start taking care of my batteries, specially the more expensive 65C + batteries.
Aug 02, 2012, 06:54 PM
Registered User
Quote:
Originally Posted by hoppy View Post
4.23V is over the recommended max charge voltage for lipo cells. If that voltage is correct, I would replace that charger.
4.2V and lower is OK. Lower full charge voltages giver longer cycle lives.
Charging to 4.1V/cell substantially increases cycle life.
How was the value 4.2V arrived at? Is that the nominal voltage of a Li-Ion battery.
Aug 02, 2012, 07:17 PM
REVOJohn's Avatar
Quote:
Originally Posted by theaveng View Post
How was the value 4.2V arrived at? Is that the nominal voltage of a Li-Ion battery.
No: Nominal is 3.7 by the basic electrochemistry
4.2 is max charging voltage the cell can hangle before things start to go wrong.
Aug 02, 2012, 07:28 PM
Registered User
In that case I wouldn't charge my battery higher than slightly above nominal. Say 3.9 or 4.0. No reason to stress the chemistry. I guess chargers are adjustable?
Aug 02, 2012, 07:58 PM
Space Coast USA
hoppy's Avatar
Most chargers are not adjustable.
3.9V is only filled to 63% of capacity and 4V is 84% of capacity.
4.1 - 4.15V is a good number for a full charge.

If your charger has a "Fast Charge" option that will fill it to ~4.15V+/-


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