[oldtamiyaphile]

As I pointed out earlier, the 50 and 150mah cells displayed a linear correlation between rated capacity and discharge time. The 100 cell faired worse only because it's of inferior quality. IE, despite the high charge current the 150 still ran about three times as long as the 50.

WRT the whole charge time/run time theory. Since so much charge current is being wased as heat, you might well find that a 4 min charge at say 500ma would actually yield a longer runtime, as opposed to 1000ma for the same lenght of time.

At this point I must assume your charger only goes down to 1amp, which might have 'decided' your charge current?

Ni-Cads are rated in the following way. I'm sure there are some asian copy cat rogues that don't use this methodology though, but it is the electronics industry standard.

Charge rate is C/10 for about 16 hours (delta peak monitored cut off). They are then left to sit on a shelf for two weeks to self discharge, after two weeks capacity and voltage are measured. The above tests should be conducted at 25 degrees C.

What does this mean?

The Mah/Voltage rating is a guaranteed minimum. Typically a correctly, freshly charged cells will have 1.4 volts and between 20-30% higher capacity than their rating.

So, it's entirely possible to charge at say 300ma and get a cell full to 100% of it's rated capacity.

Perhaps a second round of testing is in order. Use only one type of cell and report on the affects of charge current on final capacity.

Superfly, you're not charging at 1000mah. You could connect the charger to the mains (provided you stepped down voltage to ~3v DC) and the car would have 100's of amps at it's disposal, but would still only draw the 300ma it normally does. As I've said, Ni-Cads in a controller can put out 100amps (or close) but they certainly don't deliver all their current to the car. Matter of fact, you're giving the charger less current than alkalines could deliver.