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need to diagnose trouble with battery

after months of band-aiding my battery on a charger every few weeks, I need to figure out why it's not holding a charge.

(prior posts have stated that I wasn't driving the car long enough to keep a full charge, but that's changed as I now drive the car more than enough to charge the battery. Also previously mentioned was a LoJack putting a drain on the car 27/7 and that's been removed (one less annoying car alarm in the world, do I get an award?).

So the battery's still not reliable. I need to have the hardware tested. If I put the [Panasonic stock] battery on a charger, it will fully charge and last for 3-4 weeks until it slowly drains enough to be unreliable -- so I'm thinking it's the alternator or wiring or something, no?

(BAMA membership forthcoming.)

-fptm

Reply to
Fruit Pie the Magician
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What is the voltage measured accross the battery when you rev up the car to al least 2500rpm? Should be over 13.8V If not you have a bad component in the altenator or regulator circuit. If it is over 13.8 then you may need to buy a westco or other AGM battery. Robert

Reply to
Robert

The very first thing I would do, is check t see if the Alt. belt tention is set properly. Even minor loseness will cause the battery to not get a full charge. This is a common thing and a "low cost item to fix".

Bruce RED '91

Reply to
BRUCE HASKIN

Well it turned out [after much procrastination] that my battery was at fault. (It's a 1997 Miata, so I guess it's time for it to die.)

Order " OCV: 12.30V Load V1: 4.89V Recovery V: 11.75 Load V2: 2.48V Test Number: 329 Rated CCA: 520 Recharge Battery and Repeat Testing "

Reply to
Fruit Pie the Magician

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