Battery, charging system and starter testing

The local shop that used to check these things "free" has decided to charge $40 irrespective of the fact that I'm a pretty good customer of theirs.

I have a little "idiot-light"-type tester but it won't check these thing under a load and I'd like to enhance my own ability to test before I spend $40.

Does this seem like a reasonable choice? 100 amp adequate, etc?

http://www.harborfreight.com/cpi/ctaf/Category.taf?CategoryID=444&pricetype=

Thanks!

Don

Try Schucks. Looks like there are a couple of them in Beaverton. They test alternators and starters for free around Seattle. I think some NAPA stores test also.

Thanks, Paul! But, I assume (maybe incorrectly) they test them on the bench/out of the vehicle . . . . . . Don

We don't have any Schucks around here, but Advance Auto, Auto Zone, [never been to but I would gess] Pep Boys, do it for free,and in the vehicle [which only tests your alternator & starter] underload. Any loaded tester should test correctly whether, or not the battery is in the vehicle. I dont think our local Napa does it, but it's a very small store. BTW a electronic tester will pick up a going bad battery before a resistor type will.

It's $14! Buy it. For a non-commercial use it will do the job. Then you don't need to be concerned with is auto-zone or Napa open, just go into your tool box and you have it.

When I worked at the transit system we used a similiar one to check the big 50D batteries coming back from the contractor (yes we had a contracted battery service). It save the mechanics a lot of wasted time putting in bad batteries.

thanks for the find...I'm ordering one.

Tom

That Harbor Freight tester works, but it tests ONLY the battery, not the alternator or starter or voltage regulator. For what it is, it's fine and it is certainly worth $14 plus shipping. Just don't expect it to replace a complete electrical system tester.

Eagle said:

That Harbor Freight tester works, but it tests ONLY the battery, not the alternator or starter or voltage regulator. For what it is, it's fine and it is certainly worth $14 plus shipping. Just don't expect it to replace a complete electrical system tester.

Click to expand...

I went to HF yesterday afternoon and bought one. It SAYS it tests charging system output and starter draw . .. . 'can't imagine why it wouldn't; on, at least, a "basic" level. And, no, I wouldn't expect this unit to perform the functions of a $100+ "complete electrical system tester." But, I think I'm going to be happy with it and will be able to do a little more diagnosis and save a few $$. I didn't get a chance to use it last evening but I did open the box, read the instructions and I think it looks well built and like it will last for my non-professional use.

Don

I'll bite. How is it going to test the starter?

Apply Ohm's Law :lecture:
It can be used to measure voltage drop during cranking; (actually any voltmeter could).
Then using an ohmeter, measure the resistance of the starter cable and subtract the resistance of the cable from the overall resistance and the result will be the resistance of the starter.

I condemn starters if the voltage drops below 8V while cranking. The reason I ordered one of these was the ability to load test the battery.
Tom