charging life packs - RC-Monster Forums

t-maxxracer32 · **charging life packs -** 01.22.2010, 02:17 PM

hey guys i bought one of those turnigy 4500 mah life packs and have yet to get a good run with it. Im charging it with my 12010i hooked up with the lba10 balancer and everytime i charge it (up to 95%) the charger only reads that it puts in maybe 50-300 mah each time.. ill run the pack for 2-3 minutes and it will die.. so ill charge it up and then it will get possibly 200-250 mah.. but the charger reads that it is 95% full.

am i doing something wrong? my basic settings..

A123 cell charge, 4.5 amps (tried 8 and it did the same thing..) 4500mah

i charge it at the a123 setting on my balancer.

do the life packs soak in so much mah so quickly that the charger wont recognize it? I wouldnt mind this, but my charger sais the pack is done and simply it is not.

im going to try charging it without the balancer and see what happens.

thanks for any input

JThiessen · 01.22.2010, 02:35 PM

You may have a bad cell. Try putting your charger on Nimh, drop it down to 1 amp or so, and let it run for a bit until it gets over the 3.x cell votage.

_paralyzed_ · 01.22.2010, 02:47 PM

^^x2 bad cell

t-maxxracer32 · 01.22.2010, 03:35 PM

well the volts on it are right and when running it for the few minutes it works it does have power.

but ill try what you said

t-maxxracer32 · 01.22.2010, 06:39 PM

so its not the problem with my settings or the fact that i need to up the cells voltage... if it is a bad cell id have to get it replaced... sent an email to hobbycity and they said send it in and theyll inspect it then replace it......

then went onto usps and calculated shipping. its gonna be like 14 bucks for shipping.

a brand new pack is only 25.

i guess i should just ship it back to them and if they dont warranty it then its not a huge deal.

_paralyzed_ · 01.22.2010, 07:59 PM

Quote:

Originally Posted by t-maxxracer32

so its not the problem with my settings or the fact that i need to up the cells voltage... if it is a bad cell id have to get it replaced... sent an email to hobbycity and they said send it in and theyll inspect it then replace it......

then went onto usps and calculated shipping. its gonna be like 14 bucks for shipping.

a brand new pack is only 25.

i guess i should just ship it back to them and if they dont warranty it then its not a huge deal.

well, hobbycity seems to be good to customers when they contact them. I would imagine if you ask they will probably give you free shipping on your next order, or maybe even send you 2 packs for the trouble. Let them know this as an added expense due to their product, and be very clear and specific about the failure so they don't just throw a voltmeter on to test it.

I'm willing to bet half the people with returns just don't bother, and that they won't even test it, but once they recieve yours they will ship a new one out. They probably have millions

sikeston34m · 01.22.2010, 09:26 PM

Quote:

Originally Posted by t-maxxracer32

well the volts on it are right and when running it for the few minutes it works it does have power.

but ill try what you said

I've been thinking about this entire problem, and something just doesn't sound right.

Then it hit me!

Go into the setup for your ESC and change your Low Voltage Cutout to 2.2 to 2.4 volts per cell.

Your ESC is still setup for regular LIPO!

t-maxxracer32 · 01.23.2010, 02:24 AM

Quote:

Originally Posted by sikeston34m

I've been thinking about this entire problem, and something just doesn't sound right.

Then it hit me!

Go into the setup for your ESC and change your Low Voltage Cutout to 2.2 to 2.4 volts per cell.

Your ESC is still setup for regular LIPO!

you were right it was set to cutoff at 6.2V

would have never thought about that..

I hope that works but its not as if it cuts off immediately. the batteries just have no power...

ill give it a try right now n see whatsup.

thanks

sikeston34m · 03:03 AM

Quote:

Originally Posted by t-maxxracer32

you were right it was set to cutoff at 6.2V

would have never thought about that..

I hope that works but its not as if it cuts off immediately. the batteries just have no power...

ill give it a try right now n see whatsup.

thanks

You should see what that's doing on an Eagletree.

The ESC will limit or shut off amp draw at or below the LVC setting. (goes dead)

Stand back folks! It's getting new life breathed into it! LOL

I'm sure it will run fine now.

I don't know what your setup is, but the Lifepo4 cells will hold about 2.8 volts per cell under 100 amp load.

2.8 volts per cell is well below where you had the LVC set at.

Yeah it's gonna run for a few minutes, but the ESC will limit amp draw at the LVC setting of 3.1 volts per cell.

The amount of the limitation is whatever the battery will push out before the 3.1 LVC setting. Which may only be 30 amps or so.

_paralyzed_ · 01.23.2010, 02:57 AM

damn sike, good thinking. makes perfect sense now that I read it.

t-maxxracer32 · 01.23.2010, 03:50 AM

just another reason as to why this forum is needed!

went out and tested it for like 5 minutes and it seemed to work. will get full results tomorow

thanks!

JThiessen · 01.23.2010, 01:05 PM

Great thinking Sikes...

T-maxx - what are you running this pack in? Also, is the pack a 1S, 2S, 2S2P?????

t-maxxracer32 · 01.23.2010, 10:03 PM

2s2p

my stampede.

sikeston34m · 01.23.2010, 10:10 PM

Quote:

Originally Posted by t-maxxracer32

2s2p

my stampede.

So how's it working now?

Did you get a full run in with it?

t-maxxracer32 · 01.23.2010, 11:06 PM

been pretty busy today with homework and what not, but i took it out right now and ran it for a good 5 minutes with no loss of power.

I just got the new 4x4 slash today so i tested it with that and it ran great! you were right. it was just the LVC.

thanks again!