Tell us about yourself!
To anyone who makes batt charger if charging flatter batt use headlight globe in series to limit current, or could burn out supply. Don,t ask! Eg 12v batt, use 12v halogen bulb in pos line(100W). Globe will glow dimly till current drops then go out- can then bypass globe.
These make top battery charger, just increase feedback resistor to regulator ic to get 14v ,7v, 13.4v out, add ammeter. Switch off before changing volts out.
I simply load any cell to test by using a dmm on the 10a setting. good AA or 18650 will read say 2.7a.
Controlling Motor Speed
Large Motors Class