Solar Panel Battery Charging

[Hugh_374319267]

I have a small Maplin solar panel charger which I use to keep the leisure battery topped up when it is fully charged and in storage.I do this by using the crocodile clips provided but this meant I had to disconnect the battery from the van.I now need to keep the battery connected to be able to store my pre set radio programmes, but thats another storey.

I decided that that if I used the cigarette lighter connection I could use a cigarette lighter socket, fixed in the bed locker and run cables to the battery terminal clamps.

I have set this up, checked the voltage at the cigarette connector and when in use it is producing a variable voltage between 8 and 16 volts. This follows right the way through to the end of the 2 wires ready to connect to the battery quick release clamps.

When I connected the cables to the clamps and checked the voltage it was down to between 2 and 2.5 volts measured across the clamps but if I released any 1 of the 2 cables from the clamp the voltage shot back to the start voltage 8 to 16 volts. Reconnect back down to 2 to 2.5 volts.

Anybody any ideas why.

Many thanks

Hugh

 

[paul_374410560]

this sounds weird, have you checked that the connector you are plugging in to the cigarette holder matches up, some female connectors ie swift ones do not match up to car accessory male parts

 

[ProfJohnL]

Hello Hugh,

I guess you have other equiepment connected to battery clips. This will represent a 'load' and will try to use the power from the solar panel. As the solar panel has a limited power capacity the other equipement will drag the solar panes voltage down.

To be able to keep your battery topped up with the solar panel, you must isolate all the items you don't want powered.

 

[Dave_374330759]

How small is your panel, the small Maplin one is only rated at 1.5w @ 17v = approx 80mA and thats in bright sunlight. You might find that just the radio memory is pulling the voltage down (have you checked what current it takes). It sounds as though you need a bigger panel, even 5watts at 17 volts is only 300m/a and as you you start drawing current the voltage will drop significantly

 

[Hugh_374319267]

Hi all

Thank you for your replies as I said the voltage is the same through all the connections. I had not thought about the radio but I will check that one out.I cannot think of anything else that is connected to the battery when the van is switched off at the control panel.

Regards

Hugh