my 5s a123 pack shot? - RC-Monster Forums

t-maxxracer32 · **my 5s a123 pack shot? -** 01.15.2008, 09:44 PM

i went to the track today and drove my xt8 with no problems and when the battery dumped (dumped instantly) i just drove it up to me and unplugged it.

i get home right now to charge it and it reads 14.8V and it sais output voltage too low so i cant charge it..... i have it set to charge at 8 amps and im using the 1210i to charge it.

anyone know anything i can do?

when i start to charge it it will only charge at about .45 amps then it dies in a couple minutes reading the low output voltage.

thanks!

gtxracer · 01.15.2008, 10:09 PM

Check the battery tabs and all connections.

t-maxxracer32 · 01.15.2008, 10:23 PM

well if the connection was bad it wouldnt make any type of connection at all right?

Arct1k · 01.15.2008, 10:25 PM

just an idea - try setting it as a 4s pack to get some volts in it and then swap to 5s...

MetalMan · 01.15.2008, 10:31 PM

Just put it in NiMh mode at a couple amps and let it put a couple hundred mAh into the battery. Then it should be good for regular A123 mode.

MTBikerTim · 01.15.2008, 10:56 PM

How well do the A123 cells cope with over discharge? I'm wondering as I am going to have some spare cells and I was thinking about sticking 4 in a stock brushed stampede with no cutoff.

t-maxxracer32 · 01.15.2008, 10:58 PM

well i ran it down to 0% and all i had to do was put it to nimh mode and its back in its normal goodole charging mode now

metalman thanks alot!

i charged it at 14cells for about 3 minutes and the volts shot right up!

its good to go now

highflier · 01.15.2008, 10:59 PM

The hyperion chargers treat it like a lipo, It will only trickle charge if voltage is to low. Either repeat several times until you hit minimum voltage then it will kick into full charge rate to use another method to get it some amps.

1) if you have 2 packs parallel them for a few minutes. Pack 1 will xfer e to Pack 2
2) do like above post say and use NMHI. BUT WATCH IT. if you forget and walk away it will kill pack. Just put like 500 MAH into it then go back to standard charge

OH and your pack is just fine... it does not hurt these things to heavy discharge them :)

PS you would be served well to config your a123 packs into groups of 3 cells.
Then you can Zip charge them. I do that most of the time and if I get LV from hyperion on the occasion that I am using it... I just zip charge for 1 min and then Hyperion works fine.

t-maxxracer32 · 01.15.2008, 11:03 PM

i feel like the zipcharging method would be hard on your batteries.

or no?

ima pm you and learn more about it.

highflier · 01.15.2008, 11:10 PM

Over on RC groups there is a guy trying to kill his A123 packs. He is charging at 20-30 amps. No problems yet. He is at around 300 cycles now and says the packs at not showing any age.

I personally set my up to charge at around 10-15 amps. No need to charge faster then I will be using them. Since I run 5s, That means I could average 30 AMPS and it would time out perfectly. However I have 3 sets.. and Never run out of charged cells :) I have seen no issues at all and there is a ton of data by everyday flier that say these cells are just not going to fail no matter what you put them through.

Highflier

It

t-maxxracer32 · 01.15.2008, 11:38 PM

i thought you said it has to be done in 3s sets or w/e?

highflier · 01.15.2008, 11:51 PM

sorry typo..... I meant to say 6s.
E-maxx 9xl, BK warrior, 6s1p A123

Zip charging 15' 18 guage wire

Highflier

lincpimp · 01.16.2008, 12:00 AM

Not to sound like a dumb ass, but what is zip charging? Any specific equipment needed? I am guessing that it is a123 only.

t-maxxracer32 · 01.16.2008, 12:06 AM

Quote:

Originally Posted by lincpimp

Not to sound like a dumb ass,

lmao!

idk why but i laughed so hard at that

anyways.

heres a link

http://www.rcgroups.com/forums/showthread.php?t=747911

highflier · 01.16.2008, 12:08 AM

Do not zip charge lipo!!!!!!

http://www.rcgroups.com/forums/showthread.php?t=747911

The motherload of info on zip charging is in above thread.

Super short summary.

By using a length of wire and specific gauge, one can reduce current flow. thus
15' of 18 gauge speaker wire to connect a deep cycle battery to a 3s A123 pack.
charge will be about 15 amps to start and fade down to 2 amps. ( Most of the time around 10 amps)

when votage at pack reaches north of 11.5 your done!!!

Cost to make, is a couple of bucks.
Ability to charge a E-maxx pack in 10 min. PRICELE$$ :)

Highflier
PS as you read above threadlink you will find others use shorter wire and charge faster... as fast as 30 amps. who on this thread can charge packs that fast....
Yea I am sure I will get flamed by somebody who does LOL