Civic battery drain.

Honest John Back Room » Technical matters
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Mon 20 Mar 2006 10:55
Civic battery drain. - davemar
I'm asking this one on behalf of a friend's car.
He's got a mid-90s Honda Civic 1.5 16v engine I think.

If he leaves the car overnight it seems the battery hasn't got enough grunt to start the engine. But if he disconnects the battery overnight it starts fine. So I decided to measure the current drain to see if it was exessive, but it was only around 30mA, which shouldn't really drain a newish battery overnight.
I checked the charging voltage and that was fine, so it seems the alternator is doing its job.
I'm a bit mystified to how the battery could apparantely lose its charge with just a small current drain. I haven't actually seen it not start myself, so haven't been in a position to test it when it is in the 'morning after' state.
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Mon 20 Mar 2006 11:01
Civic battery drain. - Peter D
And the charging voltage was, age of battery ? and does that model has a dimming interiot light. I hace come across these that come back on when cold and flaten the battery Regards Peter
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Mon 20 Mar 2006 16:02
Civic battery drain. - davemar
The charging voltage was 14.5v, and the battery is less than 6 months old I think. I'm pretty sure the interior light is a basic one, and I think he has it turned off the whole time anyway.
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Mon 20 Mar 2006 16:16
Civic battery drain. - Peter D
Thats fine but it stil may be an alternator fault so disconnect the alternator overnight and see if it fixes the problem. Regards Peter
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Mon 20 Mar 2006 16:17
Civic battery drain. - jimmyw
With the boot closed drop one of the back seats forward and check if the boot light is on, an old favourite, or glove box,take bulb out and try overnight.
Also check starter motor connections for corrosion.
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