Alternator regulator voltage / 2003 Accord, 4 cyl.

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.

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.

Is 14.6V normal charging V in a Honda Accord (2003, 4 cyl)?

To change the voltage regulator do I need to replace the entire alternator?

Is that a shade tree job or best done by a garage?

Thanks.

Alan Browne > wrote in
:


>
> Is 14.6V normal charging V in a Honda Accord (2003, 4 cyl)?
>


Is the alternator original, or is it a replacement?

Are you measuring the voltage with the engine warmed up? Voltage will be a
bit higher when the engine is cold.



--
Tegger

On 2012-02-15 18:55 , Tegger wrote:
> Alan > wrote in
> :
>
>
>>
>> Is 14.6V normal charging V in a Honda Accord (2003, 4 cyl)?
>>
>
>
> Is the alternator original, or is it a replacement?

Original. Why?

> Are you measuring the voltage with the engine warmed up? Voltage will be a
> bit higher when the engine is cold.

The above was cold. After a short trip today the idle voltage was 14.35
to 14.4 and with a good load on (no not that!) [high beams, rear
defrost, heater fan, radio loud] it was 14.15 V. Looks good.

Later I'll check it at higher RPM (1500 - 2000) when there's someone
around to sit in the car.

Thanks.

Alan Browne > wrote in
:

> On 2012-02-15 18:55 , Tegger wrote:
>> Alan > wrote in
>> :
>>
>>
>>>
>>> Is 14.6V normal charging V in a Honda Accord (2003, 4 cyl)?
>>>
>>
>>
>> Is the alternator original, or is it a replacement?
>
> Original. Why?



Because OE alternators are not known for failing early, and especially are
not known for overcharging. Aftermarket units, on the other hand, are not
known for operating properly.



>
>> Are you measuring the voltage with the engine warmed up? Voltage will
>> be a bit higher when the engine is cold.
>
> The above was cold. After a short trip today the idle voltage was
> 14.35 to 14.4 and with a good load on (no not that!) [high beams, rear
> defrost, heater fan, radio loud] it was 14.15 V. Looks good.
>
> Later I'll check it at higher RPM (1500 - 2000) when there's someone
> around to sit in the car.
>



I think your alternator is just fine. If it were overcharging, you'd be
seeing well over 15V.

About 10-years ago, Honda had a brief run of (Delco?) alternators that were
defective and were failing in overcharge-mode. But this was an aberration.
The typical symptom was lots of light-bulb failures.


--
Tegger

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.


>
> 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*.


>
> 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.


>
> 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.


--
nomina rutrum rutrum

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).

Alan Browne > wrote in
:


>
> Okay, if it comes to that I'll order it and have it swapped at the
> next oil change.
>


If I were you, I would not monkey with the OE alternator unless you are
using Genuine Honda replacement parts. And I would certainly not replace a
working OE alternator with an aftermarket unit.

Aftermarket electrical parts are universally bad, and you will regret
having used them in spite of the dollar savings from OE.

I do not believe there is anything wrong with your alternator. If the
engine-hot system voltage is below 14.5, and you're not blowing bulbs, then
your alternator is just fine. Leave well enough alone.

--
Tegger

On 2012-02-16 09:30 , Tegger wrote:
> Alan > wrote in
> :
>
>
>>
>> Okay, if it comes to that I'll order it and have it swapped at the
>> next oil change.
>>
>
>
> If I were you, I would not monkey with the OE alternator unless you are
> using Genuine Honda replacement parts. And I would certainly not replace a
> working OE alternator with an aftermarket unit.
>
> Aftermarket electrical parts are universally bad, and you will regret
> having used them in spite of the dollar savings from OE.
>
> I do not believe there is anything wrong with your alternator. If the
> engine-hot system voltage is below 14.5, and you're not blowing bulbs, then
> your alternator is just fine. Leave well enough alone.

I agree, which is why I said, " ... if it comes to that ..."

I just want to be sure that the reason the prior battery failed in less
than 1 year is not due to my alternator/VR output.

Your comments on OE v. aftermarket well noted.

Alan Browne > wrote in
:


>
> I just want to be sure that the reason the prior battery failed in
> less than 1 year is not due to my alternator/VR output.
>


If the system was overcharging to the point of battery damage, you'd have
substantial boil-off of battery fluid (as you originally noted), your
headlights would appear a bit too bright, and light bulbs would be failing
all over the car.

I think your previous battery was just defective. It happens. Don't know
what kind of battery you bought, but I've had excellent experiences with
Interstate, and with Eveready.

--
Tegger

On 02/16/2012 06:41 AM, Alan Browne wrote:
> On 2012-02-16 09:30 , Tegger wrote:
>> Alan > wrote in
>> :
>>
>>
>>>
>>> Okay, if it comes to that I'll order it and have it swapped at the
>>> next oil change.
>>>
>>
>>
>> If I were you, I would not monkey with the OE alternator unless you are
>> using Genuine Honda replacement parts. And I would certainly not
>> replace a
>> working OE alternator with an aftermarket unit.
>>
>> Aftermarket electrical parts are universally bad, and you will regret
>> having used them in spite of the dollar savings from OE.
>>
>> I do not believe there is anything wrong with your alternator. If the
>> engine-hot system voltage is below 14.5, and you're not blowing bulbs,
>> then
>> your alternator is just fine. Leave well enough alone.
>
> I agree, which is why I said, " ... if it comes to that ..."
>
> I just want to be sure that the reason the prior battery failed in less
> than 1 year is not due to my alternator/VR output.

as you should. batteries fail from over-voltage long before bulbs blow.
in fact, bulbs are one of the last things to go. definitely make
sure your regulator is within spec - you don't say who manufactured your
alternator, but when denso regulators fail, over-voltage is one of their
commonest modes.


>
> Your comments on OE v. aftermarket well noted.
>
>

tegger's a little over-dramatic on this. denso don't make regulators -
they're sourced from a number of different suppliers, then used or
re-sold by denso. same with bearings, etc. bottom line, if the
components used are good, there's no reason after-market is any worse
than o.e. the qualification to that statement however is that people
buying after-market don't want to pay o.e. prices, so it's a loaded
gamble that they're going to get lower quality.


--
nomina rutrum rutrum