Date: Mon, 30 Jul 2007 22:23:49 -0600
Reply-To: Martin Jagersand <jag@CS.UALBERTA.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Martin Jagersand <jag@CS.UALBERTA.CA>
Subject: Re: CDN Tire: Two 6 volt vs One 12 volt battery question
Content-Type: text/plain; charset=ISO-8859-1
If we focus on the fridge (being the appliance running all the time)
1A for 24h is 24Ah/dat, 3 days = 75Ah, 4 days 100Ah etc.
Normally one would want to dimension the battery so that it is about
double the capacity of the actually fre4quently occuring use. Another
rule of thumb is to never discharge more than 80% of capacity.
So a 100Ah battery should really only be used to 50Ah regularly,
and 80Ah occasionally.
Since you don't mind using the space under the bench seat, I would
recommend the two 6V golf cart size batteries. This gives you 150-200
true Ah.
The AGM battery's 100Ah would be a bit marginal.
Martin
----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Malcolm Stebbins
Sent: Saturday, July 28, 2007 10:42 AM
To: vanagon@GERRY.VANAGON.COM
Subject: CDN Tire: Two 6 volt vs One 12 volt battery question
Having read the post regarding Canadian Tire's battery sale, CDN Tire has
2 batteries that seem to
be what I want/need:
http://www.canadiantire.ca/browse/product_detail.jsp?FOLDER%3C%3Efolder_id
=1408474396673605&bmUID=1185573901792&PRODUCT%3C%3Eprd_id=845524443277145&
assortment=primary&fromSearch=true
and
http://www.canadiantire.ca/browse/product_detail.jsp?FOLDER%3C%3Efolder_id
=1408474396673605&PRODUCT%3C%3Eprd_id=845524443290779&bmUID=1185574219890&
assortment=primary&fromSearch=true
If your browser breaks up those URLs, The specs are:
6 volt: $85 CDN - Features
* Deep-cycle 6 V battery can be used with solar panels as a source for
stored energy when used
in conjunction with inverters
* 390 minutes of reserve capacity (at 25 amps)
* 150 Amp Hours (at 6 hours)
* Also fits golf cart applications
* 6-month manufacturer's warranty
* 6-month free replacement
12 Volt:; $213 CDN Features
* Renewable energy deep cycle battery
* 12V sealed AGM (Absorbed Glass Mat) deep cycle lead acid battery
* Designed to be used with Xantrex PowerHub 1800 (11-1877) or as part
of any battery bank for
a
renewable energy system
* 100 ah at 100 hour rate
I know VERY little about electricity. but I do know that 2, 6 volts can =
12 volts.
So which is "better"? My intended application/use is:
Battery under rear seat (so no space limitations), to power all stock
interior lights and my
lap-top through an inverter, but NOT the Dometic fridge; I have a top
loading Waeco compressor
type fridge that draws, on average (at 70 Deg F) 1 amp per hour. I figure
that 3 to 4 days of NOT
running the van (to charge the batteries) will be about all I'll need.
I also plan to maybe add a solar panel to the top of my van, maybe a 2 or
3 amp panel.
I also have a SurePower 1315 and I called them and they said their unit
would not care if it sees
One 12 volt or Two 6-volt batteries.
Cost is really NOT a factor, (but 2x$85 = $170, or $213) I want the best,
more reliable, and
longest running set-up.
So which is "better".................... I fear the answer will be "There
are trade-offs...."
Malcolm (who barely understands watts = amps x volts, AC vs DC etc.)
--
Martin Jagersand
University of Alberta
http://www.cs.ualberta.ca/~jag/