Solar setup in a micro camper

Hi guys,

New here. I’ve been spending the lockdown converting my mk2 Kia Sedona into a 2 berth day van / camper. I’m getting to the final stages of the main build and am almost ready to connect up all the electrics.

Solar panel, charge controller and switch pack all fitted, electrical items all in place (just TV, lights, fans, USB chargers, kettle, radio) and battery is ready.

I have 2 questions if anyone can help?

  1. The switches have a linked earth / ground which I plan to wire to the car’s bodywork. The leisure battery is not connected to the car’s main battery. Do I also need to run an earth from the -'ve leisure battery terminal to the bodywork?

  2. I think I read somewhere you can break it if you connect it all up in the wrong order… but can’t remember where and can’t find it now. Is that right?

Many thanks,


Greetings & Welcome!

The answer is “It depends”.

If all your loads are connected back to the battery via negative wires, then it is possible to have a totally isolated system. If any of the loads are grounded to the vehicle, then you need to also ground the battery to the vehicle.

You’re kind of missing the boat with a totally isolated system though. Solar is the least efficient and least reliable of the various options available. The typical order of charging usually looks more like this:

  • Charge while driving via isolator/relay/solenoid etc.
  • Charge via generator & battery charger.
  • Charge via shore power & battery charger.
  • Charge via solar.

Solar is slow, inefficient, and depends on the weather and the time of year, plus it forces you to park in the sun during the summer. All the better choices work anytime day or night, and in any weather.

Many people do claim to use solar as their primary source of battery charging, which is a poor choice, but with backup plans like above, they make it work. Without backup plans, you’re setting yourself up for failure.


"Stay home, stay safe, and remember social distancing." ~ Van_Dweller

Many thanks for your kind and helpful advice.

I have an isolator but was hoping to get away without it. It sounds like I should use it.
The available space prohibits a generator.
I have a battery charger and “loose” shore power connector. I also bought a fixed hook up point for the van but am clueless on installing it. I’ll take another look at it.

Thanks again

Another question if anyone has a moment. What gauge of cable should be used to connect the starter and leisure batteries (both 110 mAh) via the isolator. They will be approx 2 metres apart. Could I just re purpose a set of jump leads after replacing the clips with proper connectors?

Thanks again in advance,



An extra heavy duty pair of jumper cables works just fine.


"Stay home, stay safe, and remember social distancing." ~ Van_Dweller