Hello Kcobra,

When charging at 0.1C, the charge efficiency is not all that good. You actually need to put in around 150% to come up to a full charge. The "forming" charge goes for 16 hours to make sure the cell is fully charged. The damage done by the extra hour of charge at this rate is minimal.

The battery manufacturers follow an IEC standard when determining the capacity of their cells. The standard calls for charging at 0.1C, allowing the cell to rest for from 30 minutes to 4 hours, then running a discharge at 0.2C.

The same standard also is used to determine cycle life. One of the methods used to determine cycle life involves charging at 0.1C for 16 hours.

You are correct in that extended trickle charge is not good for NiMh cells, however a couple of hours at 0.1C is not considered extended trickle charging.

Tom