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Do I have a dead cell?


#1

Hey guys,

So I just checked my LiPO and the highest volt on the cell is 3.7 and the lowest is 3.3 everything else is in between.

Is this okay and is there a way to get them all the same or doesn’t it matter?


#2

Yea that can be normal if not been charged properly so what would say is get a good balance charger and balancing them properly.


#3

I have a iMac b6ac I am balance charging it now. When the highest volt cell gets to 4.2 will it stop and let the others catch up??

How does it work


#4

No what it will do is supply less current and it will then charge through the balance leads. So if your normal charge amp is 4amp then when one cell reaches 4.2v it will cut the amps right down to about 1amp or less and slowly level them out.


#5

So I can just leave it and it will all balance out? That cell is now 0.5 v lower


#6

The highest cell keeps increasing and is now 0.7 higher than the lowest cell


#7

I think you have a dead cell but I’m no expert.


#8

I’ve stopped charging them, they are currently at

1 = 3.88
2 = 3.92
3 = 3.84
4 = 3.89
5 = 3.86


#9

Same thing happened to me with a Zippy Compact 5A 3S 20C. Cells were 4.18- 4.20 - 3.81. I discharged them a bit, then balance charged it with my iMax B6 charger, but could never get that last cell to get over 3.8~ or so. I tried this 2-3 times, but could never pull more than .1A while balancing charging very slowly at .5A to 1A different times. I came home one night and checked my cell and of course, the one bad cell became 0.00 and the battery was toast :(.


#10

Nice! What was your amperage set to while balance charging them?


#11

6.0 is the max my charger will go. My batteries are 8500mah


#12

So wait… You meant 0.07 and not 0.7?


#13

Yeah sorry


#14

Then it should be fine… Pls check comma next time…


#15

How don’t get them all the same, when I charge it the highest one keeps increasing faster than the othersand the lowest increases slowly


#16

Just keep it on a balance charge and should sort it’s self out once they start to reach 4.2v


#17

Is the amp okay or should I use lower? My batteries are 8500mah and my charger does 6.0amp max


#18

The only way to find if you have a dead cell is to get them all at 4.2v which just keep it charging for now but then when charged need to use them. If you find that that same sell drops in voltage quicker than any other then yes you have a dead sell as the resistance it lower so it charges and discharged quicker. But keep charging for now.


#19

I charge at 4amps. Depends on you battery is it 6s1p ?


#20

the battery should have a charging c rating. that times the battery amp hours (8.5) gives you the max you could charge it. often it’s higher than the charger can do. regardless it’s better on your cells to charge slowly and discharge slowly. go to 4.2 and not under 3.5 if you want them to last. or even 4.15 be better