On 2012-02-15 21:30 , jim beam wrote:
> On 02/15/2012 10:55 AM, Alan Browne wrote:
>> Honda Accord, 2003, 4 cyl.
>>
>> Last winter I bought a new battery and installed it. Worked fine.
>>
>> This winter from about New Years, if I didn't start the car within a 2
>> day period the battery was dead (a couple crank turns at best).
>>
>> After 2 days the voltage would be under 12 volts. Should stay at about
>> 12.6 or a little more when not in use. So I'd either jump it or if I had
>> time I'd charge it up with a charger at low rate.
>>
>> I measured the key-out current as 45 mA. That wasn't draining it.
>>
>> I brought the battery in the house and charged it slowly. Once charged,
>> it would discharge (open circuit) from 12.9 to 12.2 V in about 5 hours.
>
> open circuit voltage is not a reliable measure of battery health. make a
> dummy load out of some head light bulbs and then read it it.
A fully charged battery should not drop below 12.6 V, never mind to
12.2V in a few hours with no load on it.
That was one of several tests trying to find the fault. Since the
battery was relatively new it was the last thing I suspected.
>
>>
>> I took the battery back and they tested it and gave me a new one on
>> warranty. (NAPA (Cdn arm of UAP)).
>>
>> Brought it home, installed it in the car. Everything seems fine.
>>
>> However, I checked the charging voltage at idle and was surprised that
>> it was 14.6V. I would have expected it to be 14.2 - 14.4 V. Above 14.4 V
>> I'd expect electrolyzing out H2 and O2.
>
> indeed.
>
>
>>
>> Is 14.6V normal charging V in a Honda Accord (2003, 4 cyl)?
>
> i think it's a little high*.
As in my other post, after the car has run for a bit (5 - 10 minutes)
the voltage drops to under 14.4 - maybe no issue. I need to check at
higher RPM as well.
>>
>> To change the voltage regulator do I need to replace the entire
>> alternator?
>
> well, you can replace the regulator, but it depends on who made the
> alternator as to how easy it is and availability of separate regulators.
> if it's denso, regulators are relatively easy to get, but genuine denso,
> the reliable ones, are much harder to get and so expensive, it's
> comparable to buying a whole reconditioned alternator.
>
>
>>
>> Is that a shade tree job or best done by a garage?
>
> most garages just replace the whole unit - only shade trees and nerds
> replace regulators.
Okay, if it comes to that I'll order it and have it swapped at the next
oil change.
>
>
>>
>> Thanks.
>
> * before you go too much further into this, check the accuracy of your
> meter. particularly if it's cheap digital - sometimes those things can
> be way off.
I was thinking of that but I need a reference voltage to it with. (It
is a cheap digital).
--
"We demand rigidly defined areas of doubt and uncertainty."
Douglas Adams - (Could have been a GPS engineer).