Hi Buffy61. The size and number of panels is largely dependent upon the load (s) that you will have. Basically you need tsites down and add it all up the work out what loads will be in use most of the time. For example, if you are running a car fridge in the van you need to have a permant panel attached to the van to cover that load.

The next point is one that mant people have opinions on. Do you need portable sola panels? My answer to that is a YES .

They allow you to obtain fully charge from the sun when you are pulled up at a site for a while. Usually you need to repositionother once or twice a day for max charge. However there is the problem of the theft of the panels if you are away. If you attach a tether stainless steel wire to them and your van via a padlock that normally provides the security that you need. I use about a 8 mm cable in my case and have had no hassles at all.

As regards to the installion of them a number of things are majorly important here.

1. What ever regulator to use it needs to be installed at the batteries and not at the panels. It's all to do with  loss of charging voltage. If you use the regulator at the panels you will need much larger cables to ensure  sufficient charge at the batteries.

By installing the regulator at the batteries and with sufficient size cable your batteries will always be fully charged when sufficient sun is available. In my case, I use 10mm cables and this allows me have cable lengths of up to 10 meters in length. There are times when the sun and your van are not parked in a good place, trees, etc. by having panels portable and the system wired this way you can usually get your panels into a position that will allow charging. In my case I have a 120 watt panel on the roof of the van and two portable 80 watt panels. 

I have used this system on the road for the last 3 years and it has never lets us down. One thing I just thought of! Go to an auto electrician for your cables as they usually have the cable you need in stock and once yowe tell what it's for they will be able to supply what you need.

In regards to what regulator to use, I use a C Tec Dual smart charger, as it has inputs for sola panels and charging from the tow vehicle. That way no matter where your charging source comes from the batteries will be charged to the best they can be.

To back all of this up we have a generator to keep the batteries charged for those days when the sun just don't shine.

Trust all of that makes sense, it you clarification on any area please feel free to PM me if you want. As an electrician and worked with battry systems in my employmant I am aware of some of the pitfalls that people can run into. It has also been my misfortune to come across people who may be in the business but just don't know what they are talking about, they just simply don't know so be sure that you go to someone that does wpknow the right answers. Take someone who does know.

Its a major expense so you need to get it right. 

All the best for your journey and trust it all works out for you

Regards

Brian.

-- Edited by briche on Tuesday 30th of April 2013 11:50:23 AM