Trickle charging battery from solar panel - what relay?

[deejay47]

I have a small solar panel which I would like to use to trickle charge my leisure battery. What relay should I fit to stop it flattening the battery?
Thanks

[kevtherev]

Hello and welcome to the forum
Why not tell us a bit about yourself and your van?

[deejay47]

Hi, I have a VW LT35 actually, which is part-converted to a motorhome, and also used to pull a caravan. I have a small cheap solar panel which I want to use to trickle charge the leisure battery when I'm not using the van much, and I just need to know what sort of relay I should use for this.
Any advice much appreciated, thanks.

[ghost123uk]

Hi and welcome to here were you will find all you need to know (and lots you don't )

As far as I know you don't need a relay on a solar panel, it's output is DC via semiconductors, so when it is not charging, it will just sit there doing nowt.

Do you know the output of your small solar panel in "Amps" or "Milliamps" as many small solar panels are very weak output (depends what you mean by "small" )

[boatdog]

hi deejay its not a relay you need its a charge controller, this acts as a regulator so when the battery is charged it usually burns excess energy off as heat, you need one that has a scolt (think thats how its spelt) diode that stops the electric charge going from your battery back to your solar panal when the voltage in the battery is more than your panal is making, eg night time. hope it helps

[Red Westie]

Most of the DIY ready panels, even the small ones, already have a diode protected circuit to stop this happening..just read the specs on the box.

Martin

[ghost123uk]

Most of the DIY ready panels, even the small ones, already have a diode protected circuit to stop this happening..just read the specs on the box.

Martin

Agreed (as I said ) plus it was mentioned that this was a "small cheap" solar panel and as such the modest current it is likely to produce will not cook the battery but will just act as a trickle charge. (imho of course )

[boatdog]

is your panal one of those plug in ones with about a 10 watt rating?
if it is it will be fine to clip it on your battery without any regulation, when you say small approx what size is it? i use a 60watt panal so it usually kicks out about 3 amps on a sunny day so over a 10 hour period will re charge the batteries back to full

[Red Westie]

I think you will find those small panels are only 1.8 watts so even less at around 0.15 amps....

Martin