Solar v Generator v Mains Power

GeeTee, if your van has an inbuilt charger then there is no need to regulate its output again - it's output (~14V) might be too low anyway for the solar regulator's input voltage (19-21V) to have any effect.
Just wire the solar regulator's output to the battery posts as well , via a suitable fuse. You might want to check if your inbuilt charger puts a little load across the battery if its not plugged into 240V - some do -, if so, wire in a switch to isolate it and take this unwanted load off the battery.
Klaus

You cannot regulate a mains battery charger through a solar regulator.
You will need to isolate the solar panels from the system if you wish to charge the battery from the mains supply. If you have sufficient solar capacity don't bother with the mains charger unless you absolutely need it. When you are on mains power you will not be using the battery, so even if the battery is down, the solar will bring it back to full charge on the first day. I have my campervan fitted with solar and do not have a mains charger at all, or connected to the vehicle system. Solar is best if it is a complete stand alone system.
If you are interested I do sell solar panels all sizes, and have 80w multi-crystalline panels for $595.00 incl GST and freight and 100w multi-crystalline panels for $695.00 incl GST and freight to most locations.

GeeTee 'sufficient capacity' is what you require to run the equipment you need. Solar power is nothing short of sensational, basically if it is correctly specified and installed, you can forget it is there and it all looks after itself. If you are only running a few lights and your TV/DVD/CD player for normal hours like most do, a 100w solar panel should cover your requirements. However, if you use this equipment with high volume the power consumption certainly rises dramatically. For normal listening volume, 100w panel should be fine. Deep cycle batteries for longevity should only be charged from solar using a quality solar regulator. A Fullriver HL95 which is designed for a 10 to 12 year life can only be charged from solar or a three stage mains battery charger. With a quality pulse width modulation solar regulator will give you a top quality, low cost value for money, long term trouble free solar solution. The important thing after that is to ensure you install it correctly with the correct size wire and connections.
GeeTee and Mr. Z you can contact me at solarpanel@dodo.com.au

Have a look at this site
www.caravanandmotorhomebooks.com
These books are by Collyn Rivers an experienced solar power person. Although I do not agree with everything he says most of the information is good.
I use unisolar panels to back up my system and these are free standing 2x32 watt units which allows me to place my van or camp in the shade with the panels out sunbaking. The panels are fold up type with a 10amp regulater built in.
In most situations there is enough power to keep everything going indefinately. We usually run out of food and the liquid of life and then we move.
I also have an onboard 240v charger and a Arid twin charge 12v system built into the van, this allows the van to be charged from the alternater when travelling and from 240v when connected at a van park or such.
Another good site is www.12volt.com.au

I increasingly recommend that, because larger output modules are now available at more affordable prices, it makes increasing sense to charge from solar only. I have had my OKA set up this way for the past six years or so.

Re charging via a solar regulator from a mains charger.

This is technically possible with soome regulators, but not many such chargers have sufficiently high voltage output for this to be worth considering. However, from the regulator's perspective, dc is dc and it cares not what generates it. This is actually spelled out in the Plasmatronics handbook.

My own now-32 module home system operates in exactly this way. The output from the modules goes into a PL 40 regulators. So does the output from our big rebuilt ex-Telstra 48-volt 30-amp charger. Both can be and are used simultaneously. Nevertheless whilst the above is feasible I do not recommend doing it unless you have an electronics background (for example, whilst you can increase charge voltage output by adding parallel capacitance, that is a non-no for the regulator).

I would not personally use a chain-store mains charger and solar charging at the same time. It is technically OK from the battery's viewpoint, but there is some risk of 240-volts AC appearing in places where you would not wish to experience it.
Collyn Rivers