"Caroline" <caroline10027remove@earthlink.net> wrote in message
news:bDLqd.3823$6K5.2845@newsread2.news.atl.earthl ink.net...
> "bin yan" <binyanmail@yahoo.com> wrote
>> Hi,
>> My '90 civic seems to drain battery quite quickly. It was out of power
>> this morning (after 4 days of not use). I could jump start it without
>> any problem. After running the car for a while, I shut off the enginee
>> and restarted the car, no problem. But after a couple of hours or so,
>> the battery seems getting quite low, to a point that it just barely
>> started the car after a few trials.
>>
>> The battery is probably more than 5 years old (diehard). I think it is
>> time to replace the battery. But could it be the alternator or
>> something else? I am pretty novice on cars.
>
> Some ideas:
>
> Could be but you're about due for a new battery anyway. On my 91 Civic,
> the
> average lifetime of any battery (including one Diehard) in it has been 4.5
> years.
>
> Old batteries do tend to wear down alternators. It's prudent to replace
> them
> before they die completely.
>
> I suggest replacing the battery and then getting back to the group.
> Interstate
> is a very popular battery name around these parts. For the first time
> ever, I
> broke away from Sears Diehards and bought an Interstate a few months ago.
> Costs
> about $20 more, but I think it's got a 7-year warranty.
>
>> Any suggestions for me to test it further before taking it to a shop?
>
> Autozone will do a free test of the battery but I personally haven't had
> the
> best experience with them in this particular matter.
>
> You could go buy a voltmeter from Radio Shack or similar, check the
> battery
> voltage with the engine not running, then with it running and the
> headlights on,
> and get back to the group. You should have at least 12 volts with the car
> not
> running. It should go over 14 volts with it running and headlights on.
>
> Do check that, say, the overhead interior car light switch isn't stuck in
> the
> "on all the time" position.
>
>
And it is prudent to check the charging voltage after putting the battery
in. It should be between 13 and 15 volts (low when the weather is warmer,
high when the weather is colder). I replaced a friend's alternator (the
diodes were almost completely toast) and checked the charge voltage. 17
volts! Replaced the regulator (separate device in his Ford), and he wanted
to give the battery a chance to prove itself. Once he replaced the battery,
the system worked like a champ.

I was looking for possible low voltage, but I'm glad I checked. A battery
will put up with that for a couple of minutes, but no longer.

Mike