Solar Panel

[Zen Zero]

Sorry this is not boaty at all, it's for a camping van.

A new solar panel has arrived in the post and will shortly be fitted to the roof of our camping van.

I'm about to order one of these:

http://www.maplin.co.uk/dual-16a-solar-charge-regulator-266145

Now the instructions state that the negative of the panel must go to the regulator and then to the battery.

Since it is a negative earth vehicle, why can't I just connect it to the nearest bit of metal and save copper, weight and trouble?

Thanks!

:-D

 

[Stemar]

They could well be thinking about a caravan or boat installation, where the -ve isn't earthed. Personally, I'd run a twin flex from the panel to the regulator then earth the battery -ve.

BTW, before ordering, have a look at at http://www.sunstore.co.uk/EP-Solar-Duo-Battery-Solar-Charge-Controller-12-24v-10A.html. It's a little more than the Maplin one, but I think you'll find it's quite a bit smarter and more efficient as a charger. I haven't had mine installed long enough to be sure, but it certainly seems to do what it says on the tin.

 

[pvb]

Since it is a negative earth vehicle, why can't I just connect it to the nearest bit of metal and save copper, weight and trouble?

Because the campervan body may not be electrically connected to the chassis. Run a separate negative wire.

 

[Zen Zero]

Thanks for the advice! I'll have a look at that other controller, it's not that much more.

I shall take the negative from the panel to the regulator and thence to the vehicle frame. It's all electrically integrated, of this I am quite sure.

Thanks again!

 

[VicS]

Thanks for the advice! I'll have a look at that other controller, it's not that much more.

I shall take the negative from the panel to the regulator and thence to the vehicle frame. It's all electrically integrated, of this I am quite sure.

Thanks again!

The Sunstore regulator is a PWM controller. Marginally better than the Maplin one which simply disconnects when the battery reaches 14.4 volts and reconnects when it falls to 13.4


As far as wiring to the van is concerned I'd wire the panel with twin flex to the controller but consider taking the common output to an earthing point on the van body as you suggest.

 

[nigelmercier]

Run a separate negative wire.

and fit an anode

 

[William_H]

If the solar panel has arrived in the post then I can only guess that it is quite small in power and physical size. In which case presumably you have a decent sized battery in the van so why fit a controller. A solar panel around 10w will never overcharge a battery of more than 85AH size. So without a regulator (controller) all charge goes into the battery when ever there is sun.
Larger panels obviously can overcharge a battery so need a regulator .
Why not use the money earmarked for controller to buy a VSR voltage sensing relay to get charge from the engine alternator to the camper battery. (assuming you have a separate battery. Which you should have.
good luck olewill

 

[V1701]

They could well be thinking about a caravan or boat installation, where the -ve isn't earthed. Personally, I'd run a twin flex from the panel to the regulator then earth the battery -ve.

BTW, before ordering, have a look at at http://www.sunstore.co.uk/EP-Solar-Duo-Battery-Solar-Charge-Controller-12-24v-10A.html. It's a little more than the Maplin one, but I think you'll find it's quite a bit smarter and more efficient as a charger. I haven't had mine installed long enough to be sure, but it certainly seems to do what it says on the tin.

My two PWM controllers, from ebay & half the price of the sunstore one for same thing, two years in, no problems...

View attachment 30462

 

[Zen Zero]

My two PWM controllers, from ebay & half the price of the sunstore one for same thing, two years in, no problems...

View attachment 30462

what's going on in that picture?

one solar panel, 2 batteries, two controllers, ok how are they connected together?

 

[V1701]

what's going on in that picture?

one solar panel, 2 batteries, two controllers, ok how are they connected together?

2 panels, a 20w for engine battery, a 40w for service, each with its own controller. I guess I'm potentially, theoretically "wasting" some of the juice from the 20w but hey...