Date: Wed, 17 Jun 2009 08:05:57 -0700
Reply-To: Don Hanson <dhanson928@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Don Hanson <dhanson928@GMAIL.COM>
Subject: Re: Battery/Charging system questions.. A lot of info included..
In-Reply-To: <BAY132-DS4A870C350216BCA0FD744A03C0@phx.gbl>
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Thanks, Dennis
It must be a bad ground that is causing me to see the two batts in series
because when I isolate the batteries by removing the ground straps at each,
I get a 'normal' reading of about 13-14, but significantly lower on the
coach batt.. Or, when I test another battery sitting out on my bench, I get
readings in the proper range with my meter...
The 'relay not making good contact'...that is likely, too. I noticed that
while the relay 'clicks' every time, I recall that it used to almost
"CLUNK", quite loudly and forcefully, so that I could even feel it through
the driver's seat. It seems less 'forceful sounding' now.
As I recall, that relay is also supposed to be grounded..maybe that is
where my batteries are getting into series somehow..a bad ground at that
relay? This electrical stuff is difficult when you only know just a little
about it, enough to think you know, but not enough to actually know
enough...
I drove about 45 mins yesterday then immediately flipped on the Westie
'gauge' near my sink and it gave me an amber/yellow indicator rather than
the red...so some current is going to the coach battery...which probably is
shot, the way I've run it down a bunch of times and being 3 yrs old now.
I stuck a big 50 amp fuse in the supply wire to the secondary battery,
putting it inside under the passenger seat right at the main battery post.
I thought, since the supply wire goes across near my fuel tank, fusing it
might be a good idea, just in case.
One more weird thing (probably weird only to someone like me, who knows
little) The lighted toggle switch that I installed into the relay 'supply'
wire that comes from my ignition: It has three terminals, in, out and
ground. I assumed the ground is to make the LED in the toggle light up when
the switch is on...and this happens despite one of the wires being
disconnected under there. I have to get serious and see exactly which wire
is loose...but that shouldn't be like that, right? What a mess!...
Don Hanson
On Wed, Jun 17, 2009 at 3:22 AM, Dennis Haynes <d23haynes57@hotmail.com>wrote:
> If you really had 17 to 20 volts across the battery you would have an awful
> gassy bubbly mess. You are either using the meter wrong or you have a bad
> ground and are seeing the voltage of the two batteries in series.
>
> 2 or 4 volts across the relay while closed is an indication the relay is
> not
> making a good contact. This is common with the large relays as the small
> current battery charging presents will allow the large contacts to oxidize
> and foul up, especially with the cheaper of these relays. You also can have
> a bad battery. A shorted cell can cause all sorts of havoc.
>
> Usually battery charge lines are not fused. Fuses do not make sense as you
> have a power source on both sides. The wires need to be large enough to
> carry both the charging load and all appliances on that battery.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Don Hanson
> Sent: Tuesday, June 16, 2009 3:15 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Battery/Charging system questions.. A lot of info included..
>
> From a dummy...
>
> The last few months my coach battery hasn't seemed to be staying charged
> up as well as in the past. I've changed nothing recently.
> So I got out my handy dandy Radio Shack digital meter today and began
> poking around. I find lots of Volts. Dunno what it should be, but I seem
> to have too many at the Vehicle battery and plenty at the Coach
> battery..however, my water pump is kinda slow and the Westie Indicator
> lights are on the Red bulb most of the time (when the engine is not
> running)..
> My system:
> I have two identical NAPA batts. of around the same vintage (aug '07)
> These are "sure start 65" BCI 42 with 500cca and 250amps. One under the
> passenger seat (the vehicle batt) and the Coach batt under the driver's
> seat. I have a big wire (fused, of course) across (vehicle to coach batt)
> which feeds a big 'mechanical' can 3 terminal relay, also under the drivers
> seat. This relay is controlled by a wire from the ignition and the wire is
> also switched (that supply wire from the ignition to the relay)...I wasn't
> sure about starting the vanand how the two batteries would inter react
> during start up, so I began by having that secondary switch off whenever I
> started up...That proved to be un-necessary but it is nice to be able to
> cut
> the power to the secondary battery without shutting off the van..
> Ok, so I run the van and check the relay...Flip the switch from the
> ignition to excite the relay and "Click!" it works fine..
> But the numbers (from my digital meter) don't make sense....Oh yeah, when
> the van is running, the Westie stove-front power indicator light goes
> Green...engine off..Red...on Green.
> From my digital meter: Vehicle battery..Van off reads 20.6 Van running
> reads 21.8
> Coach battery...Van off reads 17.3 Van
> running and relay active reads 21.7
> I double checked with an older analog meter and my Radio Shack one is
> functioning fine...though I wasn't sure which scale to read on the analog
> meter, it is consistent with the digital one.
> So how come so many volts? Is this bad? Or is my meter simply screwy or
> my testing technique faulty?
> Also, across my 'mechanical' relay (a silver cylinder with two (+/_) large
> terminals and a 'supply' terminal..I am seeing (I think) some current when
> there shouldn't be any. I see about 4 volts across the two main (+ (in
> from
> the vehicle battery) and -(out to the accessories in the coach))
> connections. That shouldn't be, unless perhaps the relay is now faulty?
> Anybody care to take a shot at this weirdness?
> I am thinking I probably have a couple of things going on here..Maybe my
> meter is reading wrong and maybe the relay is faulty.
>
> The setup has worked pretty well for me for about 18 months including a
> prolonged (4 months) outing where the Van was used as a second bedroom and
> work/play vehicle daily..I would get about 2.5 hrs of satellite radio,
> incandescent light and some computer time before my coach battery went
> down...At present, I'd guess maybe I'd be getting about 1/4 that, so
> something is out of whack somewhere...I know I could have a more
> appropriate
> electrical system but I don't want to re-do the whole thing right now.
>
> Don Hanson
>
>
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