FYI: I inverted the $/Ah calculations in my first post. Must have been
the heat wave...

Correct cost per Ah is as corrected below. As I wrote in the previous
post I ended up buying the Exide batteries at Canadian tire. $85 on sale,
$99 reg.

> > On 7/25/07, Martin Jagersand < jag@cs.ualberta.ca> wrote:
> > >
> > > There is a 15% off sale on some deep cycle batteries at Canadian tire.
> > >
> > > I was thinking to get a real deep cycle this time. The '94 westy takes
> > > up to two batteries so I can get 1x12V or 2x6V.
> > >
> > > Canadian tire has the following offerings:
> > >
> > > A regular (consumer grade for your boat, rv etc) battery
> > > 205 min reserve capacity => 205/60*25 = 85 Ah for $119 hence cost
> > > $0.71/Ah
> >
> >
 119/85 = 1.4 $/Ah

Or an "Renewable energy grade" Excide 6V battery (Should presumably be more
> > > tolerant of cycling for instance for people who solar power their
> > > cottage and cycle
> > > the battery every night. But who knows, maybe it's just a relabeled
> > > golf cart battery...)
> > > 150Ah at 6h rate, $85, Hence cost for 2 batts $170 gives $0.88/Ah
> >
> >
 170/190 = 0.89474 $/Ah

Third option is an AGM (Absorbed Glass Mat -- one of those supposedly new
> > > better technologies)
> > > 100Ah at a fishily long 100h discharge rate. $212, gives $0.47/Ah
> >
> >
  212/100 =  2.1200 $/Ah

--
Martin Jagersand
University of Alberta
http://www.cs.ualberta.ca/~jag/