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solar panel

Posted: Sun Mar 10, 2024 6:58 am
by stuffedpike20
Is there a solar panel that can be propped in the window of a minor that will charge the battery on a car that is not in regular use?

Thanks.
John

Re: solar panel

Posted: Sun Mar 10, 2024 8:52 am
by philthehill

Re: solar panel

Posted: Sun Mar 10, 2024 9:51 am
by stuffedpike20
Thanks Phil.
My mate has got a camper van with 3 Leisure batteries connected together. Would one of these solar panels charge them all?

I know nothing about this sort of thing. :-?

Re: solar panel

Posted: Sun Mar 10, 2024 11:03 am
by philthehill
I see no reason that it should not. But charging three at a time will be slow but steady.
Make sure that the three batteries are connected so as to give out 12V not 36V.
You can get higher output solar panels but at a higher price.

Re: solar panel

Posted: Sun Mar 10, 2024 11:46 am
by stuffedpike20
Thanks Phil.

Re: solar panel

Posted: Sun Mar 10, 2024 1:36 pm
by oliver90owner
Lead/acid batteries require a minimum current before any increase in stored energy takes place. That current will depend on the battery type, size and likely state of charge.

While a 10W solar panel will likely provide that output under the prescribed measurement conditions, you would need to know the real output voltage. Usually the output from solar panels is somewhat less than the stated figure - like during the winter, the output from a solar installation may be only about one eighth of that during the summer season.

A far better installation would be a solar panel with more than sufficient power to charge the battery to 14.4V, plus a charge controller which will limit the charging to avoid over-charging the battery (beyond 14.4V).

I’ve not looked at the panel listed by PTH - I’m just pointing out the better, more definite, course of action to follow.

Re: solar panel

Posted: Sun Mar 10, 2024 2:41 pm
by les
I’m thinking along the same lines John, sounds like a plan.

Re: solar panel

Posted: Sun Mar 10, 2024 3:09 pm
by svenedin
Providing the car that is not used often is outside! Not much use having a solar charger in a dark garage.

Re: solar panel

Posted: Sun Mar 10, 2024 3:45 pm
by les
Yes you’re right and a little used vehicle is quite likely to be in said garage, as mine is. However depending on the location, there is the possibility to site the charger outside. Waterproofing could be another issue though.

Re: solar panel

Posted: Sun Mar 10, 2024 4:05 pm
by Chief
Maybe I'm just lucky, but I find mine has enough charge still in it after over a year of it sitting disconnected in the car for multiple starts, so maybe it would be as easy to just keep it unplugged when not in use?

The only reason I had to charge it again the other day was that I could hear it getting weaker from all the attempts to fill the oil cannisters I'd been doing recently.

Re: solar panel

Posted: Sun Mar 10, 2024 8:19 pm
by stuffedpike20
Thanks for the replies. :tu1: