Date: Wed, 11 Aug 2004 07:55:16 -0700
Reply-To: Vince S <gipsyflies@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Vince S <gipsyflies@COMCAST.NET>
Subject: Re: Aux. Battery-Stereo Amp question
In-Reply-To: <vanagon%2004081108230907@GERRY.VANAGON.COM>
Content-Type: text/plain; charset="us-ascii"
Mark,
I am curious. What the world are you going to run off the 1800W
inverter? Microwave, electric heater? A straight forward calculation
(not considering the inefficiency or power factor, partial load etc)
that 1800W pulls 150A of current at the 12V side. Neither you aux or
primary battery will be able to sustain this load for more than may be
15 minutes. You cannot pull this current even from the beefest cigarette
lighter circuit. Unless you absolutely need such a huge inverter for
occasional and short use of power tools you are better off with a more
sensibly-sized inverter. A big inverter also has much higher overhead
current even with no load. A big inverter also tends to make a lot of
noise due to the cooling fan unless the designer take step and cost
(vert unlikely in this market) to address it.
Costco has a very nice Coleman 400W (800W peak) inverter for only $25.
No shipping no hassel in dealing with eBay purchase. Note: even at 400W
you need to hook the inverter directly to the batter with the beefy
cable with the battery clamps it comes with it if you want to make full
use of the capacity.
On the stereo and amp I think it is good to connect to the aux amp as it
is among the electrical consumer that has higher amp-hours considering
how it is used. You would want to wire both the head unit, amp, and
changer if any to the same battery. You don't necessary have to try to
modify the head unit power wiring from the factory. I found it much
easier just run properly sized wires out from the aux battery to the
various consumers. You can get blade style fuse holders at West Marine
to fuse the wires to the head unit, power amp in the battery
compartment. You should use separate fuses for the head unit (lower
amperage) and the 300W amp (higher amperage).
- Vince
http://gipsyflies.home.comcast.net
1989 Vanagon GL Camper
1996 Land Rover Discovery
2005 Mini Cooper S
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Mark Cumnock
Sent: Wednesday, August 11, 2004 5:19 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Aux. Battery-Stereo Amp question
I am in the process of running wires to the stereo, xm unit, and
cigarette lighters,and I am bidding on a 1800watt inverter on EBAY. I am
thinking of tying the 300 watt stereo amp into the aux battery. I used
the GOWESTY kit (which just moved the wires on the relay #10 awg). Am I
asking too much of the aux battery to tie in the amp....would I be
better off pulling the fuse to the amp If I do want to listen to the
stereo. I hardly ever listen to the stereo camping...pet peeve of
mine.....but I do like the idea of the van stuff that gets you home;
tied into the main battery....and the stuff the is luxury tied; into the
aux battery.
So what so I do???