Battery low but quasi-stable--why?

[precopster]

Hmm some observations contrary to theory: http://www.learnabout-electronics.org/R ... rs_01a.php

[rocketman4321]

I agree in principle, and that's how I did the negative side test. On the positive side, with turbo and A/T, that involves wedging your hand past the hot radiator, various hoses, and intake manifold to remove the B+ cover and hook up a lead. The resistivity of copper increases about 30% from 20 to 100C, so that's really not a huge issue. (You'll tend to see if there's a problem or not--don't cheer if your drop is 0.199 volts.) The question is whether temperature opens up bad joints or loose connections.

I charged the battery for 6 hours yesterday. It was at 12.77 V right after disconnection and fell to about 12.58 V about 15 min later, which I take to be the surface charge bleeding off. Just sitting in the garage, it lost 0.1 volts in 5 hours, then another 0.05 V overnight, so it's at 12.41 now. That doesn't sound horrible, but it's also not great.

[BEJinFbk]

Age of the battery?

[misha]

...Is it simply that the 3-year-old "gold" battery won't take a charge?...

[BEJinFbk]

...Is it simply that the 3-year-old "gold" battery won't take a charge?...

Thank You.

[misha]

[rocketman4321]

Well, it does seem to charge on the charger, which is why I'm puzzled. Of course, the auto parts store only ran a load test.

A bit of an update. First, my meter had a blown fuse that mislead me. I did have the classic glove box problem, draining something over 150 mA. The central locking was another ~40 mA, and everything else was < 20 mA. I doubt that's the root problem here (even for 15 hrs that light is 22 A-hr), but it certainly doesn't help. Fixed with a shim. My daughter drove it around this afternoon, but none of the 3-4 legs were over 10 miles. Was about 12.35 V when she got home and it sat for a few minutes.