The Unnecessarily Complex Battery Tester

RE: The Unnecessarily Complex Battery Tester

electronicbiker — Sat, 13 Feb 2021 01:12:00 GMT

Here's what I do to test batteries and cells. It is all done using a Model 7 Avometer except the visual inspection.

First I look around the terminals for any sign of leakage, corrosion, green powdery stuff, and white powdery stuff. If there is any, I dispose of the battery in a safe and responsible manner.

Then I check the voltage using an analogue multi-meter set to the correct range. If it starts to droop after a few seconds I dispose of the battery etc etc. Even if the reading is steady, a too-high or too-low voltage is good reason to be suspicious.

I also check the available current using an analogue multi-meter set to the correct range. If it is well below what I expect then I dispose of etc etc... I don't recommend anybody to try this unless they know what they are doing as it can be very dangerous, and in any case never do it with high-power batteries such as lithium, silver, lead-acid, Ni-Cad, etc. Or anything big. Even something as small as a good AA cell can be harmful. You have been warned.

The Avometer, with the famous cut-out that pops up on overload, is a marvellous device for testing batteries. The 10 amp AC range also makes it useful for testing the permanent-magnet alternators as fitted to vintage motor-cycles. Never be without an Avo! (Other ancient analogue multi-meters are still available)

RE: The Unnecessarily Complex Battery Tester

bigsexy — Fri, 12 Feb 2021 13:25:20 GMT

Not a total loss. We now know the cat has a analog input!

RE: The Unnecessarily Complex Battery Tester

joespez — Fri, 12 Feb 2021 07:55:24 GMT

Awesome project dude, surely it will work really great with some more tinkering!

I remember fiddling with one of these testers once and I remember a resistor in addition to the voltage divider resistors, which added a small load to the battery to get a more meaningful reading.
But as you said the real problem lies in the contacts, I can’t believe those unreliable spring contacts are still with us

RE: The Unnecessarily Complex Battery Tester

DAB — Sat, 30 Jan 2021 18:58:50 GMT

Nice mix of analog, digital, and back to analog technology.

DAB

RE: The Unnecessarily Complex Battery Tester

dubbie — Sat, 30 Jan 2021 13:22:20 GMT

Nico,

A nice concept. And, it looks like one of those things that should work but somehow, doesn't seem to.

Dubbie

RE: The Unnecessarily Complex Battery Tester

neilk — Sat, 30 Jan 2021 11:49:43 GMT

Nico - a great project, with the story well told.

Perhaps your cat didn't provide enough input? [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-f3a438e1-ba0a-420f-8be4-0beb743e4b6d/contentimage_5F00_403.png:16:16]

Neil

RE: The Unnecessarily Complex Battery Tester

ajcc — Sat, 30 Jan 2021 09:41:34 GMT

A great and fun project!

Those charge only USB-cables are a nuisance.