View Single Post
  #2   Report Post  
Posted to sci.electronics.repair
William Sommerwerck William Sommerwerck is offline
external usenet poster
 
Posts: 3,833
Default AA Battery Pole Reversal

It's called "cell reversal". It's most-common with rechargeable devices
using nicad or NiMH cells, but I also saw it in an HP calculator that used
alkaline N cells.

Here's what happens... One of the cells has significantly lower capacity
than the others. When it hits zero volts, the other cells are pumping
current through it /in reverse/. This causes the cell to charge up
backwards, with reversed polarity.