Lipo repair

Hi guys, I'm new to RC and new to this forum. This is a great thread!

I have a question I haven't seen addressed. I have a Losi 2s 1000mAh pack. It has Losi's "Internal circuit protection to prevent over charge and over discharge", to quote from their documentation. Well, that circuitry has bit the dust. I've opened the pack, and the cells still look fine, and their individual voltage is good.

Sure it is a small/cheap pack, but it seems a shame throw it away with good cells. Is there any reason not to turf the protection circuitry (as Losi seems to have done for their more recent 2s packs). I'm running a Tekin ESC (with low V cutoff) and using the Losi wall-wart Lipo charger (LOSB1208), which I assume ha overcharge protection built in, so I'm not sure why I'd need the in-pack protection too.

Has anyone had problems with this circuitry before and/or have reasons not to proceed with bypassing it?

UPDATE:

After sitting for a day the pack is 'fixed', we'll see how long it lasts. I figure either it had a slow to reset thermal cutoff (I let it sit > 2 hours prior to pulling it open and posting the above, so I doubt it, and it was barely warm to start with), or when I plugged it into the charger that reset something in the protection circuitry. I'll keep an eye on it, and if nothing abnormal happens I guess I'll leave it. If it cuts out again, I'll take another look at bypassing the internal curcuitry.

Man I hear you on the heat Linc. Every summer people in Houston start loosing their minds, usually people on the road with a broken AC in their car.

I work on my own lipo packs, but I need help on balance taps. Do you have a link that shows wiring diagrams for the different taps? Also, what is a good place to purchase balance taps?

Thanks in advance.

[Metallover]

Click on "Lipo pack wiring" - http://www.scriptasylum.com/rc_speed/_lipo.html

Or do you need to know abaout the wires going into the connector? With standard JST-XH plugs, the ground goes into the first wire then the other cells go in order after it. If you look at a plug it's easier to do.

[auto2]

i have a few old batterys coming your way. a 5s 3700 polyquest that only makes full power after 4 laps when it gets warm.

a 4s 3700 that has a weak cell in it.( constantlly have to balance it for hours to keep it even)

are you busy? mail them out monday? lemme know ben ( need address also)

[E-Revonut]

Originally Posted by auto2

i have a few old batterys coming your way. a 5s 3700 polyquest that only makes full power after 4 laps when it gets warm.

a 4s 3700 that has a weak cell in it.( constantlly have to balance it for hours to keep it even)

are you busy? mail them out monday? lemme know ben ( need address also)

Linc is no longer doing lipo repairs or reconfigurations.

[E-Revonut]

I would like to say thanks to LincPimp and BrianG!!! When Linc said he stopped doing lipo repairs I was getting ready to send him a pack. That forced me to order the stuff I needed and I figured I'd rather destroy a $200 pack learning to rewire one than to let it sit there and go to waste! Stuff came in the mail today so it was time for me to grow a pair and cut apart a $200 Lipo! Before I did it though I took a little trip to BrianG's site and looked at the lipo pack wiring diagram. Well I finished and hooked it up to my charger and it's charging as I write this. So for a few dollars and about a half hour of time I resurrected a valuable pack! Thanks guys!

[Metallover]

Originally Posted by E-Revonut

I would like to say thanks to LincPimp and BrianG!!! When Linc said he stopped doing lipo repairs I was getting ready to send him a pack. That forced me to order the stuff I needed and I figured I'd rather destroy a $200 pack learning to rewire one than to let it sit there and go to waste! Stuff came in the mail today so it was time for me to grow a pair and cut apart a $200 Lipo! Before I did it though I took a little trip to BrianG's site and looked at the lipo pack wiring diagram. Well I finished and hooked it up to my charger and it's charging as I write this. So for a few dollars and about a half hour of time I resurrected a valuable pack! Thanks guys!

You're welcome. Donations are accepted, paypal and cash are great, along with checks payable to metallover.

Glad your pack is saved.

[lincpimp]

Originally Posted by E-Revonut

I would like to say thanks to LincPimp and BrianG!!! When Linc said he stopped doing lipo repairs I was getting ready to send him a pack. That forced me to order the stuff I needed and I figured I'd rather destroy a $200 pack learning to rewire one than to let it sit there and go to waste! Stuff came in the mail today so it was time for me to grow a pair and cut apart a $200 Lipo! Before I did it though I took a little trip to BrianG's site and looked at the lipo pack wiring diagram. Well I finished and hooked it up to my charger and it's charging as I write this. So for a few dollars and about a half hour of time I resurrected a valuable pack! Thanks guys!

Glad you figured it out. Most of the time repairs were easy, but the amount of material to completely redo a pack, and add some of my "tweaks" got costly, as did finding time...

You never know, winter may come around and i will have more time to fool with this stuff again, summer just gets very busy.

[rawfuls]

And hot as hell in LA....


Would hate to be in Texas.. Or Mexico during the summer..

Surprising, but China was literally hell..
High triple digits (around 100-120 at least..) with at least 50% humidity evey day.....

Boy was I glad to get back onto the plane.

[riverat1540]

hey link i remember u posting where u bought the balance leads and the shrink,ect. where was it again?

[Arct1k]

allerc.com sells most stuff

[riverat1540]

thanks alot guess its time to stop being lazy and get more hands on for my lipo needs,lol

[E-Revonut]

I couldn't find the shrink from allerc.com, little do dads like this stuff I still go to MA for, prices aren't bad and I get the stuff quicker from them than when I order from allerc

[riverat1540]

what size shrink do i need for a 2s 5000mah pack? the 54mm?

[E-Revonut]

measure around the pack and divide by 2. Then go up to the next available size, at least thats how I did it. The shrink is measured with it laying flat so a 54mm piece is actually 108mm around it or a circumference of 108mm