Battery Charger/Electrical Component Tester

I want to bench test my electrics (starting with the wiper motor) and I 'm considering a charger that would supply enough current for testing plus also maintain my authentic battery when I finally buy one. I was considering this one. Anyone have experience with this or similar models?

Rick OBrien
65 FHC in FL

I have no first-hand experience using smart chargers to power individual automotive components. But I suspect there could be a problem. Personally I use an old dumb transformer based battery charger for testing electrical stuff. They may be available at garage sales or on eBay. Here’s a photo of your classic dumb battery charger.

I have to agree with Bill. Smart Chargers sense the load and respond accordingly. You need an old fashion dumb charger. Or just get a small lawn mower battery. And a smart charger to keep it topped up.

What he said.

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Lots of battery chargers - including units I’ve made - produce crude full wave rectified DC. It averages at 13 or 14 volts but isn’t pretty to look at on an oscilloscope. Better to charge a battery (and let it deal with the averaging) and get a nice consistent flat DC output to test your kit with. Paul.

I bought an Optima red top car battery I intend to use in the car when the time comes. For now, it spends most of its time out of the car and hooked to the smart charger I have. I hook it up to the car when I need it (to check wiring, run the engine, etc…), and it’s always available if I need a 12v source.


I would recommend a 30 volt adjustable power supply. Both voltage and current limit are adjustable, so you can set the voltage to ~12 Vdc and slowly bring the current up to be sure nothing is starting to smoke. A very safe way to test out old or reconditioned electrical components. (Don’t do this with modern electronics particularly any with chips in them.) For example:


A lot to think about. Thanks everyone.


I always have a charged 12AH alarm battery on my bench, like this:

.Makes it easy to test small devices without the fuss of a clumsy pulgged-in device. I charge the battery about once a month on an old 6A charger. For serious testing, as I was telling someone the other day, you really need a variable power supply, say something that can go from 24V down to 1.5V. That would allow you to test things like voltage regulators or dash instruments.

Agree with Doug and Paul. A decent DC power source is safe and handy and also provides a good excuse to set up a small plating operation.

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