Thanks to all for comments on the solar tricke charger.

I was lured by the Canadian Tire commercial (they have an
in-store video of some guy going out with his buddy to start
a vehicle in spring. Buddy says no way that's going to start.
Guy says sure it will fires it up and says thanks to Canadian
tire Eliminator Solar charger...)

As Richard mentions below, VW choose a higher wattage panel,
and they probably know better what works in practice for a parked car.
(I guess I'll ask the dealer if they have any extra next time)

In hindsight connecting it to a charger or charger with timer, as Matt
suggested
is probably a more sure way to keep the battery charged.

I haven't measured the parasite load on the battery recently. Should only
be the clock, so no more than a mA or so. I have a 4 years old Optima
red top battery.  Maybe internal discharge  increases with time?

Martin

On 3/27/07, Richard A Jones <jones@colorado.edu> wrote:
>
> > To my disappointment the battery on the '82 Westy is almost completely
> > discharged. Trying to find a reason I measured the output of the charger
> > at two times: 1pm under full Alberta sun: 40mA,  at 4pm 10mA.
> > That makes only 480mW and 120mW. Far from the advertized 1.8W.
>
> Martin:
>
> Maybe your panel is defective or has gone bad.  For comparison,
> the panel that VW put in Passats a few years ago (which Ben
> McCafferty collected and spread like Johnny Appleseed....)
> have a sticker rating of 3.2 W max, 18.8 V max and 170 mA max.
> I use one with my Westy, putting the panel outside in the overhead
> luggage carrier.
>
> Richard
> Boulder
>
>