Electronic – arduino – Car Battery + Car battery Charger = 12 V Bench Power Supply

arduinopower supply

So a bench power supply can be quite expensive, and something I already have laying around is a car battery and a car battery charger. Is there any reason why a car battery + battery charger would not be a good bench power supply for stepper motors (given the need for straight 12V power, obviously the complexity increases when you must supply other voltages). I'm looking at the setup with a scope and while it's a little noisy it's nothing out of the ordinary either. I'm in the midst of testing out a RAMPS 1.4 unit with a megaduino and a single NEMA 17 motor. While I'll probably scavenge an ATX unit soon, I was wondering if it was crazy to try such a setup with a car battery. Furthermore, looking at the amps some of these car chargers put out, it seems worthy of looking into for vastly more powerful projects as well.

Best Answer

There is an safety issue that should be mentioned. Car batteries can put out huge amounts of power. If you put together a project and you have a dead short somewhere you are going to start lighting things up. A fuse is a must.

That said, a battery can work if you can't get access to a regular DC power supply. It shouldn't be recommended though as no current limiting capabilities are provided. (this is why a fuse is a must)

Another note, batteries will vary in voltage. Don't be expecting a nice clean 12V supply