Solar trickle charger?

Hi all,

My battery was dead again this morning - haven't driven the car in two
weeks, it's cold out, and the (aftermarket) alarm system sucks up the juice
like nobody's business. Has anyone ever used one of those solar trickle
chargers (a la http://tinyurl.com/7aevf )? If so, are they worth it?

Thanks

Eric

On Fri, 16 Dec 2005 13:31:36 GMT, "Eric Baber"
> wrote in
:

> Hi all,
>
> My battery was dead again this morning - haven't driven the car in two
> weeks, it's cold out, and the (aftermarket) alarm system sucks up the
> juice like nobody's business. Has anyone ever used one of those solar
> trickle chargers (a la http://tinyurl.com/7aevf )? If so, are they
> worth it?
>
> Thanks
>
> Eric

Hi Eric.

That PV cell puts out much too low an amount of current to
do much to maintain a battery. In full sunlight they
put out the full current, but only when pointed directly
at the sun. Placing it on a surface means you are only
going to get about 50% of the current which for your
example is only about 60 mA That is often not enough to
break even.

You really need one that supplies about 2A in full sun to
be able to deliver enough on average to keep a battery
in good shape or to offset parasitic loads. Thats about
a 25 watt version.

I've had one of the small ones for about 15 years and it now
puts out about 50% of its rated value of current in full sun.

I think if your battery is dead after only 2 weeks, you have
some abnormality to fix first. Maybe a bad battery or the alarm
is eating too much.

Thanks for this Red, that's what I thought. I'm quite sure it's the alarm
system; I had the original battery in the car (a '91) and it held the charge
fine until I put in the new alarm system, after which it started spluttering
after a week of not driving it. Given that the battery was 14 years old I
thought this was fair enough, so bought a new one; that doesn't hold out
longer than 2 weeks either, though. I'm quite sure it's the alarm system
though. Guess I'll just have to make a point of driving it every week at
least...

Eric

That's a decent resolution of the problem, eh? It would probably work for
me!

Chris
99bbb

"Eric Baber" > wrote in message
...
> Thanks for this Red, that's what I thought. I'm quite sure it's the alarm
> system; I had the original battery in the car (a '91) and it held the
> charge fine until I put in the new alarm system, after which it started
> spluttering after a week of not driving it. Given that the battery was 14
> years old I thought this was fair enough, so bought a new one; that
> doesn't hold out longer than 2 weeks either, though. I'm quite sure it's
> the alarm system though. Guess I'll just have to make a point of driving
> it every week at least...
>
> Eric
>

If only driving the car here were fun!! I moved to London 6 months ago and
the poor thing just sits outside the front door looking glum. Driving in the
centre of London really isn't any fun though, and getting out onto an open
road takes an hour so there's no real incentive to drive it. Fortunately
we're moving somewhere more civilised in 4 months, within 5 minutes' drive
of proper roads so dead batteries should then be a thing of the past :-)

Eric


"Chris D'Agnolo" > wrote in message
...
> That's a decent resolution of the problem, eh? It would probably work for
> me!
>
> Chris
> 99bbb
>
> "Eric Baber" > wrote in message
> ...
> > Thanks for this Red, that's what I thought. I'm quite sure it's the
alarm
> > system; I had the original battery in the car (a '91) and it held the
> > charge fine until I put in the new alarm system, after which it started
> > spluttering after a week of not driving it. Given that the battery was
14
> > years old I thought this was fair enough, so bought a new one; that
> > doesn't hold out longer than 2 weeks either, though. I'm quite sure it's
> > the alarm system though. Guess I'll just have to make a point of driving
> > it every week at least...
> >
> > Eric
> >
>
>