Comments on: Homemade Battery Tester

By: Victor Scarlesi

Victor Scarlesi — Mon, 12 Apr 2010 21:37:18 +0000

instead of the motor try wiring in a analog quarts watch in parallel with a 4.7 ohm resistor. Start the test with the watch at 12:00 . That way you’ll be able to time just how long it takes the battery to discharge with no need to keep watching and timing it.

This is a tester like I mentioned.

http://www.nickhill.co.uk/nimh-capacity-tester.html

It works quite well.

By: Gourav

Gourav — Sat, 10 Oct 2009 15:26:02 +0000

What was the resistance of your motor.

By: Duke

Duke — Thu, 30 Apr 2009 15:23:23 +0000

Some of my rechargeable batteries are getting old and don’t hold a charge very long. Will this battery tester identify one of these freshly charged, bad batteries?

By: Ex Elect Tech.

Ex Elect Tech. — Fri, 26 Sep 2008 02:12:25 +0000

Do not allow rechargeable batteries to drain to zero.
Some types will not allow you to recharge them after going too negative.

By: Rob

Rob — Mon, 24 Dec 2007 19:15:30 +0000

Sam, the design is very simple, just a motor with the multimeter in parallel. The multimeter is set to read DC volts @ or below 20

By: Sam Vallance

Sam Vallance — Sat, 22 Dec 2007 06:29:31 +0000

PS
What setting do you have on your multimeter

By: Sam Vallance

Sam Vallance — Sat, 22 Dec 2007 06:28:44 +0000

Hey
Just wondering if you put up some step by step instructions because I’m trying to make a battery tester and yours seems to be the best.
Thanks
Sam

By: Eugene Kerner

Eugene Kerner — Tue, 13 Nov 2007 01:34:19 +0000

Hi,
You need to know the impedence of the load in order to calculate the power output.
ie if you measure 1.5 volts accross a 10 ohm load then your source is good for 0.15 watts.