Date: Mon, 12 Sep 2011 16:14:12 -0700
Reply-To: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject: Re: Charging circuit wiring upgrade/maintenance report/questions
(longish)
In-Reply-To: <4E6E70A9.6040402@williamsitconsulting.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Without knowing how much current is flowing from the alternator to the
batteries, it's impossible to know what the copper and other resistive
losses are. If the batteries are fully charged and there are no loads
(headlights off, etc.) then one should see a negligible voltage drop
even with skinny wire.
But I'm no expert on these things, not seeing a reason to rework my
wiring to obtain slightly faster charging of my engine battery. With my
driving habits, it charges fine, as is.
The 12VDC > 12VDC charger for my cabin battery limits current to 7.5
amperes, fast enough for my needs. Besides, my Trojan 130 Ah deep cycle
battery was a spendy little item and I like to baby it, perhaps
overmuch, by charging it like I discharge it: slowly.
--
Jack "Rocket j Squirrel" Elliott
Bend, Ore.
1984 Westfalia. A poor but proud people.
1971 "Ladybug"-brand utility trailer ca. 1972 from a defunct company in
San Clemente, Calif., now repurposed as The Westrailia.
Sent from my kitchen.
On 09/12/2011 01:50 PM, Steve Williams wrote:
> Hi,
>
> Unfortunately, I never did any "before" measurements so I cannot see the
> improvement in my upgrades. Regardless of what the values were before,
> I am quite happy with the current <pun> situation unless someone pipes
> in to say otherwise.
>
> This was motivated by my adding a "house" battery (deep cycle under the
> back bench).
>
> 1. Installed new alternator
> 2. Added additional #6 wire from the alternator to the solenoid (left
> old wire in place)
> 3. Ran #6 wire from the solenoid my house battery (Go-Westy relay in
> place to isolate)
> 4. Replaced engine block -> chasis ground cable and cleaned contact
> points (ground paint off fender)
> 5. Cleaned transmission -> chassis ground cable contact points
> 6. Cleaned starting battery -> chassis ground cable contact points
> (ground paint off chasis bolt in point)
> 7. Cleaned starting battery posts & clamps
>
> Any of the associated "small" ground connectors also got an appropriate
> cleaning to remove oxidation, as did the bolts (as best as one can).
>
> Results...
> 14.01 volts between the alternator and the engine ground strap with the
> engine idling.
> 13.96 volts at both my starting battery and the house battery with the
> engine idling.
>
> Yes, I just went out and checked the readings again because it almost
> seems too good to be true. But then again, I don't have any draw on the
> alternator, would that make a difference? Headlights on? But then I
> wouldn't want to run at idle...
>
> What's a good test?
>
> I THINK a .05 vdc (.36%) voltage drop is totally acceptable. Does that
> sound reasonable to others "in the know".
>
> Todo still:
> Tie into the fuse panel and run a control wire from the fridge relay.
> Clean ECU Ground (how to do that on a Westy??? what a STUPID place to
> put a ground point)
> Clean the fuse panel grounds... will do when I run the wire up from my
> house panel to the fuse panel.
>
> Have I missed anything that anyone would recommend to do?
>
> [rambling starts]
> I happen to live in a part of the world where we can (and do) get cold
> snaps to -40C (-40F). I do a lot of back country skiing in the winter
> and while I never plan to be outside when it's that cold, at the end of
> a week long trip with the vehicle parked in the mountains, I like to
> have a high likely hood of it starting.
>
> As such, I've always been real anal about a well maintained
> charging/starting system and have always owned vehicles that "just
> start", even when it's that cold. Granted, with my 72 Dodge Dart (225
> slant 6), you needed to hold your head in at a certain angle, pump the
> gas pedal exactly the right number of times for the temperature it was
> outside and hold your breath. That vehicle never let ME down, but if I
> ever lent it to someone, they invariably flooded it when it was that
> cold. People used to laugh at my rusted out old vehicles, but I
> usually had the last laugh when my vehicle started right up and I was
> the one boosting the fancy new cars! Occasionally I even shocked people
> by boosting dead vehicles with my old Austin Mini, though that was more
> of a "battery charge" than a boost. The poor alternator was so tiny,
> I'd hook up with my (super heavy gauge) booster cables, let the dead
> battery charge for 15 minutes and typically things were good.
>
> Oh yeah, my 1991 Westy isn't that vehicle, I have a 2nd vehicle that's
> my winter driver... but just the same, I like to keep things in good shape.
>
> Thanks for all the pointers from people over the weekend.
>
> Cheers,
> Steve
> 1991 Westfalia
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