I would think 1.5 watts would barley keep a fully charged battery
topped up with full summer sun exposure. Don't expect it to do much in
winter low-angle sun or periods of cloudiness. The 75 watt panel on my
Westy really wimps out when the sun goes behind the trees, even though
there is open sky overhead. To address that problem, I run an extension
cord to the AC jack on the van and let my built-in trickle charger do
the work. Every couple of weeks I hook up a Schumacher SpeedCharge to
let it run a de-sulfate cycle. Sulfate on the lead plates is why most
batteries fail and lack longevity. Of course the people who sell
batteries do not want you to know that there is something you can do to
make your battery last longer.

Here's an interesting device that supposedly does a better job of
keeping batteries happy by de-sulfating the positive and negative
plates:
  <http://www.batterylifesaver.com/car-auto-battery-life-saver.html>
I know nothing about this device and never have used one, but what they
are saying seems valid. They claim you can bring a totally dead battery
back to life. Would have liked to try that on the battery I just took
to the recycle center.

Anyway, if you let a battery sit unused for weeks or months at a time,
you will kill it, so it does make sense to do something.

My 2 cents... Hope that helps.

Keith O
84 Westy "Brownie" Solar Charged Camper
90 Westy Syncro

On Dec 14, 2005, at 1:03 PM, Automatic digest processor wrote:

>   From: Al=20
>   To: vanagon@yahoogroups.com=20
>   Sent: Tuesday, December 13, 2005 7:14 PM
>   Subject: [vanagon] E-bay Solar Auto Battery Charger - any good?
>
>
>   Hi All,
>
>   If you do a search on E-bay for Solar Auto Battery Charger you see=20
>   this E-Bay'er selling some for $25 - Item number: 7571231536 for=20
>   example.
>
>   Since many of our vans are spending idle time during the winter=20
>   months, I wonder if these are a good idea/investment. I know I
> don't=20
>   start my bus every week so the idea of a little trickle charge,
> via=20
>   the cig. lighter, sounds pretty good.=20
>
>   Any opinions on these units? Are worth the $$? Or just a rip?
>
>   Al