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Old 02-23-2006, 09:02 AM
  #17464  
radio_car_racer
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Originally Posted by rbecking
Just tested one of the packs voltages seem quite even at 6A,

at 1900ma
1.437
1.438
1.436
1.437

at 3800ma (peaked at 3850)
1.536
1.537
1.529
1.529

Similar story when discharging too at 20A so don't think it's a weak cell, don't know if those figures are good or bad though.

The only other thing is that I first noticed it in my first heat I had a very heavy impact at around the 5 minute mark, a marshall was stood in the middle of the track and I hit his foot at high speed and I noticed it after then but don't know if this is just a coincidence. I skimmed and changed brushes in motor to rule that out and tried different motor, the only other thing I could think of is the speed controller? Or is it just that the cells are old and tired? They are not dumping just going very soft around 5-6 minutes.
you need to test them as a single cell under a charge load to ID a weak cell

do the following,

set charger to say 10amps & 1 cell
charge 1 cell @ this for 10 secs, no more.
make note the volts

cell 1 = 1.49
cell 2 = 1.48
cell 3 = 1.61
cell 4 = 1.49

etc for a 6 cell pack

in the above example cell 3 would be suspect.
could cause false peaking etc and would have shorter runtime than the others if you managed to charge the pack

see more here
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