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Alternator regulator voltage / 2003 Accord, 4 cyl.

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Alan Browne

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Feb 15, 2012, 1:55:30 PM2/15/12
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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.

Tegger

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Feb 15, 2012, 6:55:04 PM2/15/12
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Alan Browne <alan....@FreelunchVideotron.ca> wrote in
news:npWdnS1IHPk_YqbS...@giganews.com:


>
> 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

Alan Browne

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Feb 15, 2012, 8:04:09 PM2/15/12
to
On 2012-02-15 18:55 , Tegger wrote:
> Alan Browne<alan....@FreelunchVideotron.ca> wrote in
> news:npWdnS1IHPk_YqbS...@giganews.com:
>
>
>>
>> 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.

Tegger

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Feb 15, 2012, 8:29:42 PM2/15/12
to
Alan Browne <alan....@FreelunchVideotron.ca> wrote in
news:5NGdnchDkOeXy6HS...@giganews.com:

> On 2012-02-15 18:55 , Tegger wrote:
>> Alan Browne<alan....@FreelunchVideotron.ca> wrote in
>> news:npWdnS1IHPk_YqbS...@giganews.com:
>>
>>
>>>
>>> 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

jim beam

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Feb 15, 2012, 9:30:14 PM2/15/12
to
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

Alan Browne

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Feb 16, 2012, 8:20:01 AM2/16/12
to
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).

Tegger

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Feb 16, 2012, 9:30:56 AM2/16/12
to
Alan Browne <alan....@FreelunchVideotron.ca> wrote in
news:_92dnen2IOkcn6DS...@giganews.com:


>
> 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

Alan Browne

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Feb 16, 2012, 9:41:42 AM2/16/12
to
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.


Tegger

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Feb 16, 2012, 9:52:55 AM2/16/12
to
Alan Browne <alan....@FreelunchVideotron.ca> wrote in
news:TemdnZ5g86E7iKDS...@giganews.com:


>
> 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

jim beam

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Feb 16, 2012, 9:57:30 AM2/16/12
to
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

jim beam

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Feb 16, 2012, 10:02:24 AM2/16/12
to
On 02/16/2012 06:52 AM, Tegger wrote:
> Alan Browne<alan....@FreelunchVideotron.ca> wrote in
> news:TemdnZ5g86E7iKDS...@giganews.com:
>
>
>>
>> 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.

bullshit. you can crank bulbs up to 16V fully unregulated with no
problems unless you run them for ages like that. much more expensive
and immediate is battery failure, or even potentially ecu failure.

over-voltage is a serious problem - it needs to be dealt with
immediately, and proper diagnostics used. waiting for "bulbs to blow"
is simply retarded.


>
> 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.
>

how many batteries do you want to see him get through before you figure
out that maybe batteries go before bulbs?


--
nomina rutrum rutrum

Alan Browne

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Feb 16, 2012, 10:22:06 AM2/16/12
to
On 2012-02-16 09:52 , Tegger wrote:
> Alan Browne<alan....@FreelunchVideotron.ca> wrote in
> news:TemdnZ5g86E7iKDS...@giganews.com:
>
>
>>
>> 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

IIRC the 'dying battery' made a bit of a sloshing sound, so I believe
the fluid was likely ok.

> 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.

It was a "NAPA" (UAP to Americans). On the day I needed a battery last
winter (-23°C outside), I could not find one with the proper fit at the
usual places (Canadian Tire, Wal*Mart and so on) and ended up at NAPA.
It was more expensive and allegedly a high end battery. We'll see how
the replacement does. If it dies next year I'll replace it with
something else rather than repeat the warranty silliness - too much loss
of time.

On my prior Honda I bought an Eveready at Wal*Mart to replace the
original and it was fine.

Alan Browne

unread,
Feb 16, 2012, 10:25:08 AM2/16/12
to
On 2012-02-16 09:57 , jim beam wrote:
> On 02/16/2012 06:41 AM, Alan Browne wrote:

>> 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.

It's the original alternator. Offhand I haven't dived into the car to
see who made it.

>
>
>>
>> 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.

If I need a new alternator (doesn't look that way now) I'll either get
it at Honda (probably in NY state - everything is cheaper there than at
Honda Canada even after paying taxes bringing it in) or a "better" 3rd
party part if I can find one. Not there yet.

jim beam

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Feb 16, 2012, 9:14:47 PM2/16/12
to
On 02/16/2012 07:25 AM, Alan Browne wrote:
> On 2012-02-16 09:57 , jim beam wrote:
>> On 02/16/2012 06:41 AM, Alan Browne wrote:
>
>>> 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.
>
> It's the original alternator. Offhand I haven't dived into the car to
> see who made it.

check before you consider whether to repair or replace. if it's denso,
repair is viable. if not, then just replace the whole unit. too many
special tools required and too much difficulty getting parts for
non-denso units.


>
>>
>>
>>>
>>> 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.
>
> If I need a new alternator (doesn't look that way now) I'll either get
> it at Honda (probably in NY state - everything is cheaper there than at
> Honda Canada even after paying taxes bringing it in) or a "better" 3rd
> party part if I can find one. Not there yet.
>

last one i bought was from amazon of all places. genuine oem denso,
same price as cheapo reconditioned from my flaps.


--
nomina rutrum rutrum

Alan Browne

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Feb 24, 2012, 12:13:40 PM2/24/12
to
On 2012-02-15 13:55 , 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.
>
> 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)?

Well finally checked the charge voltage after the engine had warmed up
and it was 14.35 or so.

And revving the engine (warm) to 2000 - 2500 also had the voltage below
14.4.

So looks like the battery was the culprit. We'll see how the
"replacement" does over the next few years.

--
"I was gratified to be able to answer promptly, and I did.
I said I didn't know."
-Samuel Clemens.

Tegger

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Feb 24, 2012, 2:13:26 PM2/24/12
to
Alan Browne <alan....@FreelunchVideotron.ca> wrote in
news:R5GdnSCh5fXZWNrS...@giganews.com:


>
> Well finally checked the charge voltage after the engine had warmed up
> and it was 14.35 or so.
>
> And revving the engine (warm) to 2000 - 2500 also had the voltage below
> 14.4.
>
> So looks like the battery was the culprit. We'll see how the
> "replacement" does over the next few years.
>


Thanks for the update.

--
Tegger

Alan Browne

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Feb 24, 2012, 5:39:16 PM2/24/12
to
On 2012-02-24 12:13 , Alan Browne wrote:
> On 2012-02-15 13:55 , 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.
>>
>> 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)?
>
> Well finally checked the charge voltage after the engine had warmed up
> and it was 14.35 or so.

CORRECTION
13.85 or so. I can't explain why I entered badly above.

Alan Browne

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Feb 24, 2012, 5:39:45 PM2/24/12
to
On 2012-02-24 14:13 , Tegger wrote:
> Alan Browne<alan....@FreelunchVideotron.ca> wrote in
> news:R5GdnSCh5fXZWNrS...@giganews.com:
>
>
>>
>> Well finally checked the charge voltage after the engine had warmed up
>> and it was 14.35 or so.

CORRECTION
13.85 or so. I can't explain why I entered badly above.

>>
>> And revving the engine (warm) to 2000 - 2500 also had the voltage below
>> 14.4.
>>
>> So looks like the battery was the culprit. We'll see how the
>> "replacement" does over the next few years.
>>
>
>
> Thanks for the update.

Welcome - note the correction.
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