>So my questions are now:
>  - Is a small deep cycle wheelchair battery really better than
>    a top of the line Group 41 battery if one is normally not
>    going to empty the battery.  (we just want to have some
>    extra security that we are not going to drain the main battery
>    and be stranded.  And having a 2nd battery for a jump start
>    seems like a good investment.  I am pretty good at leaving
>    my headlights on.
>
>  - What bad happens when you use a std battery instead of a
>    deep cycle battery.  Does it just wear out sooner?
>    One person told me that the deep cycle will recharge
>    faster.  Is that true?
>
>  - Is an Optima at $130 + really worth it compared to
>    one of the above alternative (which seem to run about
>    $55-70 at Sears)

John,
I'll take a stab at this one...

First of all, lets look at the difference between a "starting battery" and
a "deep cycle battery". Starting batteries are designed for a lot of power
very quickly. To this end, they are constructed with many thin plates. The
plates are what react with the electrolyte to produce power, being an
electro-chemical reaction. Also, being very thin, these plates have a very
large surface area so's to regenerate quickly. They don't take kindly to
prolonged discharge. They like to get in quick and out quick, then go out
for a drink. Long duration discharging weakens the structure of the plates.

Now, lets look at a deep cycle battery...These are constructed with fewer,
thicker plates. The design purpose and theory is less surface area but much
stronger lattice work in the plates themselves. Basically more bullet-proof
in the long duration use of an R/V. This doesn't mean you can't use a deep
cycle battery as a starting battery for a small (relatively) engine, like a
VW. I modified my engine compartment to accept a group 27 (120 amp hr)
battery, in my diesel Westy. I don't know if this is an option for you Gas
Guys, but it would be a good thing to look into.

Now let's see if we've covered everything...your first question, "is a
wheelchair battery better"? Yes, for your house battery.
Second question, Yes, it wears out quicker.
Third,"is the Optima,etc", only if you want a battery that doesn't care how
you mount it. Otherwise, I'd stick with an R/V battery you can pick up at
any discount store ( Costco comes to mind), less than $50.

Good Luck,
Bob Bellanca
`81 Diesel Rabbit
`82 Diesel Westy (soon to be 1.9L turbo, I hope)
`84 Turbo Diesel Jetta