You can monitor a charge manually, but it takes a whole lot of babysitting and waiting for hours to see the charge voltage drop a few tenths of a volt.
Personally, it's worth my time to just invest in a smart charger to do the monitoring for me. Set it and forget it.
Measuring supposed cell voltage times the number is inaccurate, as Ni-Cad and Ni-MH cells are rated at 1.2volts per cell, yet can carry an actual potential difference between 1.25 and 1.35 volts. The value will depend on the age and condition of the cell. That means a rated 8.4v pack can have a fully charged resting voltage of anywhere from 8.75v to 9.45v... and you don't actually know what the FULL charge is, unless you've monitored the peak state during charge. When it comes off the charger, the voltage will be even higher - over 10 bolts (fully charged cells hot off a charger can show over 1.45volts.)
Save yourself some headache. Get a smart charger.
Last edited by ILLusion; January 8th, 2012 at 18:23..