Date:         Tue, 26 Feb 2002 08:37:45 -0800
Reply-To:     Alistair Bell <albell@UVIC.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Alistair Bell <albell@UVIC.CA>
Subject:      Re: Relaying Headlights
Comments: To: RAlanen@aol.com
In-Reply-To:  <8a.14a08215.29acccb7@aol.com>
Content-type: text/plain; charset="ISO-8859-1"

Frank,

I am sure you're gonna get a few responses to your battery statement!


When the engine is running and the battery charged, battery voltage is
greater than 12 volts (I read 14.1-14.2 at the battery). The alternator
output is limited to whatever the voltage reg is set at (13.8-14.4) not 12
volts. 

If you only read 12 volts across the pos and neg of your battery when the
engine is running then you have alternator and/or battery problems.

The battery must be charged at a voltage higher than 12, the upper limit
being a compromise between charge rate and over charge. Gel cell batteries
have a slightly different charge profile (both equalisation and float).

I get approx 14.0 at the dash voltmeter with no load. The addition of two 8
gauge power lines running up to the front (for aux light and relayed head
lights) makes a big difference in the measured voltage drop when those
aforementioned loads are applied. Used to be (with stock wiring) when I
turned on all the electrical loads the voltmeter would drop below 12V
(wipers, blower, lights, rear defrogger etc), now with the same loads plus a
250W aux light the voltage bottoms out at 12.5)

Alistair 



on 26/2/02 3:34 AM, you  wrote:


>> 
> Never gonna get 13 volts up at the head lamps unless you run 10 guage
> wire to them.  Even then I doubt that will work.  Battery is 12 volts that's
> it that's all.  Yes, the alternator puts out 13.? volts, but it is regulated
> to the battery at 12 volts.  There is always gonna be some current drop in
> the line which is a factor of the diameter and length of the line.  Using the
> stock wires to the headlamps with the relays bypassing the limiting switch VW
> put there will get you around 11.5 volts and the lamps.  Which is way better
> than the 9.5 volts there in OEM conditions.
> 
> Cheers  
> 
> Frank Condelli