Balance charging battery pack one-half at a time?
I've just come to learn that NiMh batteries don't need to be balanced in the way that Li-Po or Li-ion battery do. Essentially, to balance the cells you just have to slow-charge at around C/10 for a good 14-15hrs. This works because NiMh cells don't get damaged while slow-charging, even once full. This will eventually bring all the cells up to the same voltage.

Also, my charger was throwing the Connection break error because I had the wires connected the wrong way. Once I figured that out, I realized that the charge settings were wrong anyway, and I wasn't really 'Balance charging'. It turns out the charger only shows the balanced charging option when the 'Li-Po' battery type is selected. shrug

Now onto slow-charging the packs.