I'll show you a cheap way to make an amazingly versatile tool. Battery recovery, repair and charging Charge any battery, even if you don't have the original charger Electroplating Anodizing Aluminium and Titanium Electro-polishing Etching Electrolysis Operate DC solenoids, valves and pumps DC motor speed controller It's a DC power supply with programmable CV/CC constant voltage/constant current. A more professional 80V/5A version of this tool would cost kilobucks. We can build it for about $40, because we're not concerned about electrical spikes or noise.