I'm trying to wrap my head around how I need to go about balancing charging a few NiMh battery packs.
I'm using a HiTec x4 charger, which supports balancing charging up to 6 cells at a time. However, the battery packs I'm working with have 12 cells welded together in series. 12 x 1.2v cells, for a total of 14.4v (actually ~17v fully charged).
I attempted to connect the 6 charging leads to the positive ends of the last 6 cells (closest to overall negative), and the 1 negative lead to the overall negative of the pack. However, this causes the charger to throw a 'Connection break' error, which I'm assuming is caused by the other 6 cells, even though they 'sit behind' the cells I'm attempting to balance charge?
How should I go about balance charging these 12 cell packs with a 6 cell balance charger, given I'm not able to break the weld without damaging them? Should I connect the positives leads to every other cell, and balance charge them as 6 x 2.4v "cells" instead? My worry with that is the charger might damage the cells, as it's expecting 1.2v NiMh cells, and I'm giving it 2.4v cells instead.
Any ideas?
Thanks in advance.