Date: Sat, 16 Oct 2004 12:39:44 -0700
Reply-To: Doug in Calif <vanagon@ASTOUND.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Doug in Calif <vanagon@ASTOUND.NET>
Subject: Re: Second Battery / Battery wiring / 110vt Inverter
Content-Type: text/plain; charset="iso-8859-1"
Hi Dennis,
Thanks for the detailed reply, that does help.
I did some research on the inverter it is made by Xantrex.
They do seem to be quite reputable from what I can see on the net.
Here's a brief clip on them:
Xantrex Technology Inc. (formerly Trace Engineering) is headquartered in
Vancouver, B.C., but manufactures its Trace brand products in Arlington.
Xantrex is privately owned, with about 700 employees and revenues of $95
million last year.
Founded in 1984, Xantrex's Trace division is the leading provider of
inverters, which are the key components to converting the sun's rays into
usable household energy.
The most recently released Trace inverter is the Sun Tie XR, which costs
about $2,700. A complete, entry-level solar package costs $5,000 to $6,000 -
low enough to strike a chord with homeowners and small businesses.
"This year, one of the most popular products turned out to be the inverter,"
said Kevin Hagen, director of sales and marketing for Xantrex.
Just because you get a "good price" at Costco does not mean its junk!
I agree expecting 1000w delivered is asking too much from the vanagon
battery system.
There is no way I will run golf cart batteries in my vanagon, I am sweating
the idea of two full sized batteries in the van now because of weight.
I may run a deep cycle a much smaller starting battery to keep the weight
down.
I bought the 1000w inverter because it is not much bigger than the smaller
inverters and may offer a margin when asking less of the inverter.
The other choices seemed to be around 500w and I wanted a bit more for a
brief load like a power drill.
I did try it with my 9amp sawsall and it did run it which surprised me, I
had jumper cables attached to a battery.
I think the main stuff I will use it for is low draw ac stuff like lap tops
etc perhaps if they ever make a "micro" microwave for the westy I may run
one
I am thinking about 3-500 watts
Doug
----- Original Message -----
From: "Dennis Haynes" <dhaynes@optonline.net>
To: "'Doug in Calif'" <vanagon@ASTOUND.NET>; <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, October 16, 2004 6:48 AM
Subject: RE: Second Battery / Battery wiring / 110vt Inverter
> A 1,000 watt inverter for $69 probably can't really deliver 1,000 watts
> and the output may be such poor quality that anything valuable plugged
> into won't work properly but let me really answer the battery issue.
> 1,000 watts at 12 volts means you need to draw 83.3 amps, assuming 100%
> efficiency. Considering the battery voltage may drop to about 10.5 volts
> under extended load and an efficiency of ~ 90%, you really need 100 amps
> available. Add a surge factor of at least 50%, (what is the inverter
> surge rated at?) and now you got 150 amps. This is almost the same as
> your starter motor cranking a warm engine. How long do you think your
> present battery can crank the engine?
>
> Ideally, batteries should be sized to be discharged at a 5 hour rate or
> slower. You need to consider the load you normally plan to run on the
> inverter and any other loads such as lighting radio, etc. If you only
> plan to use the inverter at high load for short periods, like for a
> microwave, then sizing the battery for a two hour discharge is adequate,
> but battery life will shorter.
>
> I'll avoid the math, but to truly support this inverter, the ideal set
> up is two golf cart batteries in series. These will typically be rated
> at 225 amp hours. The equivalent in Optimas requires four batteries or
> you can also use two group 27 or 31 marine batteries. The golf cart
> batteries are by far the best solution but they take a lot of room.
>
> Now for battery charging! Since it is possible that you may want to
> charge the batteries and use the inverter at the same time, the charging
> relay and wiring have to rated to take that load, even if it exceeds the
> alternator rating. This is because the main battery will also try to
> support the inverter when the relay is closed. This is actually one
> application where an isolator may make sense but I prefer the relay. I
> suggest an RV style battery relay rated for 150 amps and 6 or 8 gauge
> wire directly run from the alternator. A better option is to use a
> battery combiner. These will connect the house battery when the main is
> charged to ~13 volts. As the voltage goes below 12, it automatically
> disconnects which will keep the inverter from draining all the batteries
> even with the engine running. If the alternator can not keep up with the
> load, the house batteries and inverter will be separated so the main
> battery can get charged again. Another benefit of the combiner is that
> if add a separated charger for the house battery, the combiner will also
> use that charger to charge the main battery automatically.
>
> Hope some of this helps.
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Doug in Calif
> Sent: Friday, October 15, 2004 7:36 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Second Battery / Battery wiring / 110vt Inverter
>
> Well Volks,
> As I am moving my way around the 87 syncro GL to Westy conversion, I
> have come to the front seat swivels and 2nd battery area of the
> conversion.
> I have decided I am going to install the swivel under the drivers side
> as well even though most of you tell me you never turn the drivers seat
> or set up the front table much.
> I figure I need to "have it" so I can also "not use it". (grin)
>
> I have come up with a way to bolt the swivels in place so I can still
> pull the whole thing off and not have it welded in the way, which brings
> me to my topic.
>
> I am installing a nice 1000 watt inverter I picked up at Costco awhile
> back for $69 It looks like it will fit nicely under the drivers seat and
> I can make some large wire connections to the 2nd battery.
> These inverters seem to really want good heavy connections to the
> battery to produce decent amounts of AC current.
>
> My main question is if you were wiring up the 2nd battery from scratch
> how would you wire it in? I do like the simple relay design VW has it
> seems to work well and do the job, no?
>
> I also would like to use a smaller battery than stock size, and here's
> my main question, are there any really good small deep cycle batteries
> that will fit into the compartment?
>
> I have seen some nice ones at West Marine for sailboats etc that look
> good but good grief a hundred bucks?
>
> I have heard there is a BMW battery that fits into the compartment and
> is smaller.
>
> I have found a fellow here in Sausalito (Arc Battery) who provides a
> deep cycle battery that is the exact size of the vanagon battery. Its
> darn heavy though.
>
> What guage wire is used to connect the two batteries together?
>
> Doug
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