Date: Sat, 17 Oct 2009 13:49:34 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Another Update: Only 13V from Alternator
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12.8 volts at the starting battery, with alternator charging is WAY out of
spec.
minimum OK is 13.8 volts.
that's how I check them too btw ...........check charging voltage at idle
with lights off, then turn on hi beams ........charging voltage should
barely drop.
'up to' 14.5 volts is OK.
I get, and sometimes sell, solid state adjustable voltage regulators for
Bosch alternators.
The guy who turned me onto them is a full time alternator/starter rebuilder
buy.
he says he sets them to 14.7 volts, which I think is a bit high for sure.
If I see 13.8 volts from my own 'good used' vanagon alternator, and
everything else works fine .......
good starter operation, bright lights etc...........I'm happy with that.
I would think that battery life is shorter with higher charging voltages.
yes, one could wonder what the charging amperage is, even when charging
voltage is all right .......
but in decades of diagnosing alternator/charging/starting issues, I can't
think of a time I had an alternator that did good charging voltage but not
good amperage.
about batteries ......I want to say 'read my lips' ........
because ..........'over all, day in and day out ............nothing works as
nicely and consistently, and is free of 'weirdness' than a good old
fashioned lead acid conventional battery.
Other batteries may be able to do other things ..........like lay on their
side, but so what. Those batteries have stricter charging requirements.
Conventional lead-acid batteries are built to work with alternators on cars
.....and they work Just Great at that.
I don't even think there is a whole lot of difference between a conventional
lead-acid battery and a deep cycle one.
And the deep cycle ones are not really completely understood I don't think.
You are not supposed to take them below about half charge I
think..........and I know a conventional lead-acid battery wouldn't like
that.
I have used a deep cycle battery as a starting battery ............there is
no difference to be discerned.
So for me......
it's real simple......use high quality conventional batteries, take good
care of them, keep them well charged .........and there are no problems.
what I think would be ideal ..........
one starting battery and the regular alternator to operate that system, as
normal.
Then whatever trick slow discharge batteries you have ....
so you can camp and use electricity from them .............then a dedicated
charging system for them. That I could imagine working really well.
----- Original Message -----
From: "Dennis Haynes" <d23haynes57@HOTMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, October 15, 2009 9:05 PM
Subject: Re: Another Update: Only 13V from Alternator
> When it comes to alternator operation, voltage is only one part of an
> equation. What is the current being delivered. With a lot of batteries it
> is
> possible to load an alternator down but you need to measure the current.
> Above 2,000 rpm the alternator should be able to deliver close to 90 amps
> at
> 13.8 volts. Output will drop at idle.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Steve Williams
> Sent: Saturday, October 10, 2009 2:21 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Another Update: Only 13V from Alternator
>
> At 08:41 PM 9/14/2009, Steve Williams wrote:
>>Just to follow up on my '84 Wolfsburg Westy with the anemic alternator ...
>>
>>I bought an alternator at an AutoZone in Flagstaff, just so I would
>>get completely stuck over the holiday weekend. I left it in the box ...
>>
>>(With the old alternator:) measured the voltage at the starter
>>battery at idle and 2,000 rpm: 13.1V with the headlights off.
>>
>>I pulled the regulator out of the Autozone alternator ... got it
>>installed (on the old alternator).
>>
>>I started the engine and measured 13.75V at the battery at idle and
>>2,000 rpm with the headlights off. With the high beams on, it
>>dropped to about 13.5V.
>
> Even after I wrote the above, I remained suspicious of the old
> alternator, so yesterday I had GoWesty install the AutoZone
> alternator, along with one of their alternator brackets.
>
> And, oh no! The AutoZone alternator measures only 12.8V at the
> starter battery with the headlights off.
>
> I measured 13.4V between the alternator case and the big B+
> stud. So, yes, I'm thinking of running a fatter wire to the
> battery. But shouldn't the voltage be higher?
>
> The GoWesty tech seemed satisfied with 12.8V, but everything I've
> learned about lead acid batteries tells me I want more voltage to
> charge it fully! Am I wrong? Do we have experts on this forum, or
> can someone point me to trustworthy advice on the inkernets? What
> about the deep cycle battery?
>
> Sorry to go on and on about this. I just don't feel like I
> understand yet what the voltage SHOULD be.
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