Date: Wed, 27 Dec 1995 11:41:15 -0500
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: drew@interport.net (Derek Drew)
Subject: Improved Voltage Regulator (more volts) For Vanagon
Yes. Great. Adjustable regulator sounds like just the ticket for me.
I am going to cc a copy of this note to the 500+ member Volkswagen Vanagon
mailing list, where a recent discussion revealed a number of people
interested in buying this an adjustable regulator for their Bosch alternators.
Someone said a good alternator shop ought to be able to dig one. I did a
World Wide Web search for alternator shops and checked out the Meckler site
and found you that way.
Please quote us a price on these units. I suspect you may sell a few of
them. I guess we'll need your phone # for ordering too, unless you've got a
way of taking orders over the net. (I wonder if I should try to
get/learn/use PGP to send my credit card number over the net. Anybody?)
Anyway, first I'll respond to the points raised so far, just for the record,
and for background for the list, and to ask a couple of questions.
===============================================
Response to Gary Heide:
===============================================
>Derek, Thanks for your inquiry on the regulator. I assume that you have
>seen a reply from DHaynes. I don't know who he is or how he saw your e-mail
>to us, but he is partially right. Normal voltage on a fully charged battery
Dennis Haynes is an *extreemly* competent mechanic and knows more about VW
Vanagons than almost anybody I know. I cc'd him a copy of my note to you in
case he had some special point of illlumination on my query.
>is 12.6 volts. Any voltage above this will keep the battery charged as long
>as there is nothing else using the power from the charging source. 13.8
>volts is the nominal charging rate that is used by over the road trucks
>since they are running for long periods of time. They are also NOT
>temperature compensated since the batteries are located outside of the
>engine compartment. Most passenger cars have their batteries in the engine
My batteries are located in trays mounted inside the van interrior
(externally vented, of course).
>compartment where the temperature changes radically. For this reason most
>all car type regulators slightly decrease the charging rate as the battery
>warms up. We checked OEM set point of the regulator that is supposed to be
>in your car and it is 14.1 volts. Transpo does make another regulator that
>the set voltage is 14.5 volts. They also make a regulator that will fit
Wow. Excellent.
>your application that is adjustable, so you can set it as you need it.
Wow! Even Better!
>Higher charging rates does shorten the life span of a battery, however if
>you need to recharge in short time periods it may be necessary to run a
>higher charging voltage. How about plugging in a small trickle charger
>while you are at the campsite?? DHaynes had mentioned running additional
I typically take a whole day to drive 5 to 20 miles in the woods then make
camp far from any campground (my Volswagen Vanagon is the rare 4x4 Camper
model). After camping, I turn out all kinds of accessories and run my 150
min. reserve capacity combination marine/starting battery down to less than
1/4 of its capacity (e.g. 12.05 volts). Then the next day, I find that the
few miles I drive (off-road) is insufficient to charge up the battery to
full charge again. The situation is compounded by frequent winchings and use
of the 12 volt chain saw to clear trees across the road. A lot of the time
I do this at 0 degrees F. temperatures.
Anyway, all this is to say I'm not camping at a campsite that has a 110 volt
power source as I am in the mountains making my own site.
>wiring, while this may be a cure, your original wiring should be capable of
>doing the job if it is in good shape and no bad connections to block the
>current flow. To test this you will need a digital voltmeter to do a
>volt-drop test. Set the meter to auto ranging or on the 2 volt range. Then
>connect the postive of the meter to the battery terminal of the alternator
>and the negative meter terminal to the battery POSITIVE post. With the
>engine running on a slightly high idle, turn on your headlight and heater to
>put a load on the alternator and then read the voltage on your meter. It
>should not read higher than .3 to .4 volts. The lower this reading is the
>better, as more of the current will be able to get to the battery. Do this
>same test on the negative side. Connect the negative of the voltmeter to
>the case of the alternator and the positive of the meter to the NEGATIVE of
>the battery. This reading should be in the .2 to .3 volt range. If both of
>these volt drop tests check good then you have no need to install additional
>wiring. If they are high then you need to look for corroded connections or
>bad wiring. You can do this test on any wiring circuit to check for bad
>connections. Typically you lose .1 volt at every connection and .1 volt for
>the wire.
Very good description of the procedure. Makes me want to do it again. But I
have performed these tests in the past (at Dennnis' suggestion) and found
that he was correct that the factory wiring was insufficient. I added (in
parallel with the existing factory wiring) 4 gague wire between the
alternator and the battery and a long run of 2 gage wiring followed by a
short run of 8 gague wire between the fuse box and the battery (Dennnis
forgot that I have already done this) and this has eliminated my voltage drops.
> On another subject, deep cycle batteries do not neccessarily require
>higher charging voltages, they are just designed to be discharged very low
>and still recover. A normal automotive battery if completely discharged and
>recharged will have a very short life.
I have been reading that a deep cycle battery charges more slowly at a given
voltage or that it has difficulty reaching full charge at a lowish voltage
when compared with the charging rates for a regular automotive battery.
Might not be true but this is what I heard. Something about higher
resistance of a battery which contains antimony, as does a deep cycle. I
might have read this in product literature from Ample Power Products of
Seattle (?) Washington--company that is fantatical about battery stuff for
using and monitoring batteries used on RVs and marine applications. I
remember clearly a claim that a normal automotive style alternator with
normal automotive regulator will not be able to bring a deep cycle battery
up to its true full capacity.
I have both an auto battery and a marine battery in my vehicle (kept apart
by relays) so this concerned me in addition to my other battery woes
described above.
> Hope this will help you, and if you need a replacement regulator let
>me know. We can supply you with a higher charging one or an adjustable one.
>Thanks again for checking our web page.
> Sincerely, Gary Heide
Glad to hear back from you so fast, Gary. Very helpful.
1. I'd like to clarify that the adjustable voltage regulator you found is
suitable for the Bosche 90 amp alternators. Harvey Chao on our mailing list
(Harvey_Chao@smtp.sv1.trw.com) had a Transpo Electronics regulator:
IB370A
Ref VR/BH Assy
BO Adj 12V
$24.95, 5 years ago
But his was installed on the 64 amp alternator that preceeded the 90 amp model.
2. Is there a voltage setting that is *too* high? ...that might burn out the
alternator? Or is it simply a matter of cooking the batteries? I imagine
turning the thing up to 15.5 volts before 4 wheeling in the mountains of
Vermont in winter next time. Then turning it back down to 13.8 volts for the
next long distance trip.
3. Are there *other* sources for an adjustable regulator for this
alternator? That is, is the Transpo Electronics model the best choice?
=========================================
NOTE FROM DENNIS HAYNES
=========================================
Reproduced for the record and for illumination and to respond to Dennis:
>The 13.8 volt regulator is fine. Some cars charge at 14.5 volts. This often
>over charges batteries. This is why most car batteries dye in 2 or 3 years.
> What you need is more current to charge larger or more batteries. As the
>OEM alternator has plenty of capacity, you should look at increasing the
>wire sizes from the alterantor. I regularly run two addidtional #8 or #10
>wires from the alternator to the fuse box and connect to sparew terminals
>that are ther. This virtually eliminates all the voltage drops that normally
>occur as accesories are being used. The lights are even brighter.
>I hope this helps.
Yes. It does help. But as explained above, I am already a convert and have
already done these mods, at your suggestion. And my desire for higher
voltage is for a special reason, as explained above, for when I am
four-wheeling and want a fast recharge. What I *really* want (are you
listening Gary) is for a two-stage regulator (such as those Ample Power
recomends) which charge at a high voltage initially and then drop down to a
lower voltage. Or, alternatively, some method of having a dashboard control
for this rather than go into the engine compartment to reset the voltage.
>PS. Using relays for the headlights and other high power equipment will make
>things work even better.
Dennis' contribution also raises the question as to whether there is some
easy, safe way to modify the Bosch alternator to put out more than 90 amps.
Ron at Wrangler Power products always poo poos this practice as he says
modifying alternators to put out more juice usually just causes them to burn
out fast. I'm interested as my winch can draw up to 380 amps in some
circumstances.
___________________________________
Derek Drew New York, NY
drew@interport.net (main address for e-mail)
derekdrew@aol.com (alternate/backup address, checked infrequently)
