Camping away from dedicated campgrounds (free camping), has its limitations in terms of available electrical power. In many cases your battery is it! But you can boost the availability with a dual battery system.
If you have a caravan, Camper Trailer or RV you might often want to take it off the beaten track and get down and dirty with nature. I’m talking about the wilderness experience; selecting a campsite that offers little in the way of services – especially electrical power. In these cases you will have to rely on your battery power, and if you plan on staying a few days and still want the convenience of light, fans, radio and maybe DVD player, etc, you will need to boost your power reserves somehow and a dual battery system could be the way to do it. In this post I will summarise how I do it. It may not suit everyone’s needs or pocketbook, but if it gives you food for thought it will be a good start.
Some consideration needs to be given to a choice of battery. Deep Cycle batteries are not meant for heavy current drains but can be discharged to lower levels. These are usually found as auxiliary batteries in a vehicle or caravan. Also bear in mind that batteries do not like being discharged and will rapidly deteriorate if repeatedly discharged below about 50% of their capacity.
In my pop-top camper trailer I use two 120 Ampere Hour AGM batteries wired in parallel. This gives me at full charge, a usable 120 Ampere Hours (240 AH / 2). This preserves the life of my batteries and provides me plenty of power, plus a small margin if I need to in emergencies. The camper is fitted with a “smart charger” so that when I am connected to mains power the batteries will charge close to 100% capacity. I also charge the batteries from the vehicle alternator when traveling and this requires some safeguards – you do not want to discharge your starter battery below its operational level…
The diagram above shows my setup. For more detailed information, I have covered all installation details and background information in a 40 page How-To guide that you can access from here.. This document will provide you with valuable knowledge and information on this topic.
I have used this system on several occasions for extended stay camps and had plenty of power for lighting, water pump, radio/CD player, TV/DVD player and so on. You can work out your battery drain by identifying all the appliances you want to run, what their current draw is and then multiply that by the use time – example:
|Lighting||2 Amps||20 hours|
|Water pump||5 Amps||1 hour|
|TV/DVD player||2 Amps||20 Hours|
|Radio/CD Player||1 Amp||20 hours|
Total 40 + 5 + 40 + 20 = 105 Ampere Hours
Go take a peek at Dual Battery System – Fully Illustrated How To Guide. And if you want to know more about batteries in general see 12 volt batteries for camping.