I am seeing a problem with my Turnigy Accucell 8150 charger where it only reads 5 cells during the battery check of my 6 cell LiPo.

Turnigy 8150 showing 5 of 6 cells

I have three 6 cell LiPo batteries, labeled battery “A”, “B” and “C”.  All three are the same make/model and purchased at the same time.  They are 20C FlightMax 2650mA made by Zippy battery (click HERE for more info).

They have been used about 7 times each, so they are still very new.  I used all three batteries last weekend, no problems.  I was able to charge batteries A and B.  But when I connected battery C, the Turnigy charger only read 5 cells, instead of 6.    I canceled the balance-charge operation and did the following to verify the battery:

  1. Using my 6 cell battery meter (see earlier post), I measured the voltage of each cell + the total voltage.
  2. Using my very expensive voltmeter (multi-meter), I measured each pin on the battery’s balance plug to verify the cell voltage as well.  I wanted a very accurate cell-by-cell voltage.  Here are the measurements:
    • Battery “C” voltage readings:
      • cell #1 = 3.48 volts – BLK-WHT
      • cell #2 = 3.48 volts – YLW-WHT
      • cell #3 = 3.47 volts – BLK-YLW
      • cell #4 = 3.50 volts – WHT-BLK
      • cell #5 = 3.49 volts – BLU-WHT
      • cell #6 = 3.44 volts – RED-BLU
      • TOTAL = 20.9 volts

Based on the above, I can conclude the following:

  • Each cell has a voltage that a reasonable voltage, meaning it’s > 3.0 volts and they are all in the same voltage range: 3.44 – 3.50 v.  So I don’t think its a “low cell voltage” condition.
  • The white balancing tap connector on the battery is good.  I was able to read voltages using the 6 cell battery meter AND by touching the metal pins with my multi-meter probes.
  • The Turnigy 8150 battery charger is also okay since I was able to charge battery A and B both before and after the false cell reading with battery C.  So the connector on the charger is okay.
  • I suspected that the pins on the charger were pushing the wiring in the battery connector.  So when inserting Battery “C” into the charger, I try pushing the wires in a little more and also moving the battery to different positions.  I was trying to see if there was a flaky wire or solder connection.
  • I thought that the Turnigy charger may have fallen-out-of-calibration.  My thinking was that the charger thought that cell#6 at 3.44 volts was off and reading < 3.0 volts.  By if it was, it should have given a low voltage error.  So its not a calibration issue.

Next Steps:

  • Not really sure what to do next.  I will try giving it a little charge, say 100 mA to see if I can bring cell #6 up a bit.  Maybe cell #6 is below some threshold that is preventing the charger from seeing it.

Any ideas?