Solar panal battery charger?

[Doc]

Has anyone tried these solar battery chargers. They come with a solar panal and are meant to trickle feed your battery.

Do they work or is it more of a gimmick.

[Mikea]

I don't see why they wouldn't work. You would have to make sure that you could achieve enough charging current and voltage according to the battery spec. This would be especially true as the battery approaches full charge, where the charging voltage needs to increase. Have you seen a particular charger?

[NiteGawper]

Hi Mick, I have one of the small solar chargers from Maplin

Solar-Powered 12V 1.5W Battery Trickle Charger : Solar Battery Chargers : Maplin

It won't charge a flat battery (not in any useful time anyway) but I use it to keep the battery topped up during the long bouts of cloud when the scope's not being used!!

Hope that helps...

Andy.

[keithatrochdale]

My brother uses one of the Maplins ones to keep the battery in his caravan topped up, but they do not give out a lot of current. At that price you could use 2 or 3 in parallel.

[Doc]

Thanks guys very helpful. It's just to trickle charge a battery between clear nights.

Say I need it to charge 40 amps that I have used during the night.

1.5w solar charger power

12v battery

Maths are:

1.5w divided by 12v = 0.125 amps

40 amps divided by 0.125 amps = 320 hours to top up.

10 hours of daylight a day so 32 days.

Is this correct.

So if I add two in parallel does that mean it will take 16 days to charge? Three in parallel will take 8 days?