The technical details of the motorhome electrics

Solar

There are two 80 watt BP solar panels, four 64 watt Unisolar panels and two 85 watt Kyocera panels   mounted on the roof of the motorhome(total 586 watts). These charge the deep cycle 'House Batteries' via a Plasmatronics PL40 solar regulator.

The solar regulator also serves as a status display showing the current discharge or charge rate, the current battery voltage and the number of amp-hours in and out since the device was last reset.

We have also added a Xantrax battery monitor - this is a wonderful device that provides all the information regarding battery status and condition you could ever want.

Batteries

There are three separate banks of batteries. One bank (the "Crank" batteries) is reserved for starting the motorhome engine. The second bank of batteries are known as the "House Batteries". These are 4 X 215 amp-hour 6-volt lead-acid batteries connected in series to provide 24-volts. (Update December 2003 - the house batteries have been replaced - over 6 years use from a set of house batteries is good going) These batteries provide power for all of the motorhome stuff (like lights, computers, the inverter etc). The last battery system is for the winch (to get the Moke in and out of the back). This is 12 volt system and is trickle charged whenever the engine is running. 

When the engine is running, I am able to charge either the house or the crank or both banks from the massive  90 amp 24v alternator. The alternator regulator can be adjusted to raise the charge voltage by up to 1.2 volts for quick charging the deep cycle house battery bank.

 

 

Lighting

All of the lighting in the motorhome is 24-volt and most of it is fluorescent - there are a couple of halogen spot lights. I have replaced all of the outside lights with LED's - these draw about 95% less power than the originals incandescent lamps.

240v Inverter/charger

The inverter (the device that takes 24-volt battery power and converts it into 240-volt mains power) is a "Trace-DR Series" 1500 watt unit. This unit also incorporates a microprocessor controlled three stage smart charger. When the motorhome has external 240-volt power attached (either mains supply or generator) the inverter starts charging the battery bank. While the inverter is a modified square wave inverter (as opposed to the favoured "True sine-wave" type, I feel that it is a very good unit for this type of application. Trace now also make a true sin-wave version that is slightly more efficient and a bit easier on high-tech gear (and of course more expensive)

Generator

For when the sun won't shine! We have a small Honda 2kva inverter generator as a back-up. These units are great, they are whisper quiet and are very easy on petrol.

 

 

 

 

 

 

 

 

Update Aug-05

After the new engine was fitted the entire crank electrical system was rewired. The house fuse and distribution board has also been rebuilt and rewired.   After two years living on the road away from mains power, we are very happy with the electrical setup. We almost never run short of power and have had to run the generator to charge the batteries on only about 6 occasions in all that time.