The Gopher

My Feedback: (1)

I have a 4s pak that came off a charger that toasted the next time I used it so I think it only charged 3 of the 4 cells fully. The esc recognized 4 cells that time but after the next charge only 3 were reading. My question is is this likley or would I look at the pak for a bad connection on the bad cell. I know which one it is by volt meter and it shows 0 or .01 volts.

Just noticed that the dead cell won't even work as a ground for another cell on the charge plug. So I'm thinking connection. I'm goin in.
I'll probably be on fire before anyone replies, but I will get back on the verdict. My other option was gonna be try to shock that cell back but I've never seen one read 0 before. I have shocked some that wouldn't charge back to life but it's risky. Wouldn't want to try it standing at a gas pump

guver

My Feedback: (325)

My guess is that it is a connection. You happen to know which cell number it is? If it's in the middle then check total pack voltage to verify a false reading. just a thought.

cagey

My Feedback: (6)

I have some turnigy packs that have done same thing. I have opened the packs and found that the solder has broken from the circuit board. I took small peice of same size wire and flattened it much as I could and soldered it aacross the break. Must be carefull as not get too shaky as it could turn to smoke fast.

The Gopher

My Feedback: (1)

Well thought I would update. Thank you guys for the response. I opened up the pak expecting a bad connection but all was well. The #3 cell is just plain dead. I tried a little 5 watt charger I had directly on the cell to see if I could defy the odds and revive it. No luck
It was reading 0 when isolated so it was a gonner. I think what happened was my cheapo charger which charged through the balance plug only Didn't charge the #3 cell but charged the rest. I did not check my voltage, just threw it in a Phase 3 squall (EDF) and flew it.
It did seem a little weaker but not what I would expect from being down 1 cell. I believe that flight on a discharged cell killed it.
The reason for my thinking is the charger quit on me and the problem was in the #3 area of the charger. one of the capacitors was bent over and just barley touching another componet metal to metal. You could tell by the board there was shorting there.and the bottom of the capacitor was puffed out of the case.
So I desoldered the cell and removed it. Sure wish I would have done that to a 3 cell I threw away because of a ruptured cell I could have tried to replace it. I havent done any more with the battery yet. I will either connect the #4 to #2 and make a 3 cell or if I could find a single the same mah. buy it and slip it in there.
I agree 100% about the shaking. During the removal a little slip with the iron got the sparks going. also got my wheeled chair going.
I rolled back a couple of feet and waited for the smoke but got lucky. no damage done THIS TIME.[:@]
Any thoughts or comments on this operation would be appreciated, any tricks I should know about , best type of solder and flux? It looked like the cells don't take solder too easily. Thanks again and I will update later

Harv2828

I have several lipos with bad cells. Is it just bad luck or am I doing something wrong. The batteries range from 4s to 6s and cannot be charged due to a bad cell in each. I run 5-6 minutes on the batteries in several planes being careful not to stress them. All batteries are fron HobbyKing or HobbyPartz. I run 32 to 60 size planes with an 8oAmp ESC. Is there any reason to pay 2-3 times the price and get better batteries from American source? Help!

cyclops2

Gopher.

Do not play Battery Surgeon on the LIPOS. They are known to burn down cars, trucks and houses.

The wheel chair limitation, really puts you & everything you own in grave danger.


Know when to say "No way ".

My best thoughts to you.
Rich

geeter

My Feedback: (110)

to be very honest with ya .li-po batterys SUCK. they are expensive, delacate with those small balance wires. must not be discharged to far, can short out starting a fire or explode. i've had many over the years and they don't last . i flew fast planes,funjets etc. i drew max amps out of them, but nothing they weren't rated for. compared to nimh or nicad, they last about one fourth as long. you pay dearly for that light weight and high amp draw. i won't buy another one. i could have bought a few nice airplanes or alot of fuel, for the money i spent on li-po batterys in the last year and a half. even the more costly ones are only a little better. so you have a 65.00 battery that has a dead cell, you can just throw it away. if you crash and the foil underneath gets broken or a hole in it, it will not hold a charge. you can add that to the expence of the lost plane or whatever. i have a tower vista powered glider with nimh 8.4 volt pack now and like it. the brushless motors are good and brushless esc's work very well but the li'po's don't last at all . better off with 1-2-3 cells instead............RON

xby-1

Sometimes funny things happen with these lipos. I've had two packs that while at the field acted like one cell was bad. Both were 3s, one cheap (Hobbypartz) the other expensive (Flight Power). After I got home and they had sat for a while I was able to charge and balance them. Unless something is loose and intermittent inside I am mystified. Both of my chrgers are balance type.

Revy

My Feedback: (1)

To throw some more fuel to the fire, I get an open circuit alarm when I plug my 3S 450 mAh packs to both the charge line and balance tap on initial start up. If I take the balance circuit off the battery, I can charge them no problem as the correct voltage is displayed on both my Tritons, EQ and 2EQ. Here's the funny part...if the charge current drops to 300mAh I can plug in the balance tap and it works like it is supposed to. IDK what the heck is goin' on, but after said procedure the pack's cells are within 0.003v of each other reading 4.202 to 4.205v.