ORIGINAL: khodges
I'd be willing to debate the statement about "single nicad does not put out more than 1.2 volts". A fully charged nicad, at least the ones I am using (Sanyo) will charge to about 1.44 volts before my peak detecting charger shuts off. 1.2 is the nominal voltage, and once the battery is discharged to that point, should be recharged, or it is likely to have insufficient voltage to reliably drive enough current to operate whatever is hooked to it, unless the system resistance is extremely low, and that is a function of more factors than just the conductive resistance of the wiring.