You can do the same thing with a $50 dollar volt-meter from radioshack and a light-bulb discharger
I do not have a problem measuring voltages with my little digital voltmeter.
But I have not figure a safe way of checking higher amp rates, I think 3 amps would burn out my meter. Is there some trick to measuring higher amp amounts?
I would think almost all the readings you get from an expensive charger, you should be able to do with the average low end Voltmeter.