Updated July 2017
The need for a generator with a caravan solar system is substantially a matter of where you will travel and when, and what you plan to use the solar for. And particularly your type of fridge. This article explains why and what is needed to run your system.
The main load with most caravans is the fridge. With most, a compressor fridge gobble up to 70% of all power. There is thus far less need for a generator with a caravan solar system if you have a three-way fridge. A three-way fridge runs on LP gas whilst away from 12/214 or 230 volt power.
Need for a generator with a caravan solar system – with compressor fridge
If you have a 12/24 volt compressor fridge you are likely to need a generator with a caravan solar system. This is particularly so is you are travelling south in the winter months. It is virtually certain if travelling north except during mid-winter. This is because there less solar input up there than most expect. It is also because it stays hot all night as well. (See How sun input is measured and also How much solar energy is available. )
Charge via the 230 volt outlet and a good battery charger
Never use the 12 volt dc output to charge – even if it is labelled ‘battery charger’. That output is usually an unregulated 13.6 volts (at a maximum of 8 amps). It’s intended use is to run 12 volt devices directly. In other words: without a 12 volt battery. That 13.6 volts is far too low to satisfactorily charge an RV battery. It may take a day or more.
Furthermore, do not (routinely) use the generator to power the system directly for light loads. Doing so gobbles fuel.
Instead,use the 230 volt ac outlet to run a 30-40 amp battery charger. If you do this the need for a generator with a caravan solar system is usually only an hour or so a day. For most small to medium sized RVs, a 2 kW generator will suffice.
The best choice of generator for small to medium sized RVs are inverter-generators made by Honda, Yamaha etc. They are quiet and their output is often ‘cleaner’ than grid power. Beware of $99 eBay cheapies however. Their very ‘dirty’ output can damage electronic equipment.
Large motor homes etc are likely to need a bigger generator. Many owners use the Onan (Cummins) range of ultra-quiet petrol and diesel units. These too are best used as noted above (i.e.to charge the battery bank rather than to run the motor home electrics directly). This is quieter and uses far less the fuel.
Large motor homes etc are likely to need a bigger generator. Many owners use the (Cummins-made) Onan range of ultra-quiet units. These too are best used as noted above (to charge the battery bank rather than to run the motor home electrics directly. This is quieter and they use less fuel. Pic:Onan Cummins.
Need for a generator with a caravan solar system – further details
Full details of how to size, buy, install and use generators to back-up solar in RVs is included in my book Solar That Really Works!
For generators with home solar systems – see Need for a generator with a home solar system.
If you found this article of value you are likely to value my books. (Bio)