You have a 12 volt solar power system on your caravan and, for reasons you cannot explain, you keep running your batteries flat after a day or two.  Perhaps the system was fitted by the caravan manufacturer and they advised you that it would be sufficient for free camping.  You have a nice big battery and a couple of solar panels, but its not enough.  Why is this happening and what can you do about it?

It is surprising how often these sort of problems appear on the RV forums and Facebook groups and, in pretty much every case, the answers are often misinformed, full of technical jargon or end up in a pissing contest between the experts.  Very rarely does a clear solution eventuate.  I find it frustrating and I bet so do most mere mortals who only want to understand what’s happening at the most basic level.

Well…after giving this considerable thought, I believe I have come up with a very simple system that anyone wanting to learn more about their 12v power systems can understand and, more importantly, can apply to their individual circumstances.

Basically, by looking at everything in terms of WATTS or, more accurately, WATT HOURS, the process becomes very logical and simple to understand.  Further it enables us ordinary folks to gain further knowledge if we want to.

Now its not perfect by any means.  There are so many variables that effect how 12v systems work, how different types of batteries behave, how the environment effects the efficiency of solar panels, all these things mean a one rule for all is pretty much impossible to come up with.  I have no doubt that any experts reading this will point that out. But one thing remains a constant.  If you take power out of your batteries, you have to put it back in order to sustain your device usage over a long period of time and how you do that will ultimately determine your success.

This Guide to 12v Solar Charging will help you to understand your system at its most basic level and will likely explain why you’re running out of power so quickly.  If you’re looking to purchase a system for your RV, this guide will also assist you to scale your system from the outset and possibly save you some money and heartache in the future.

As always, I acknowledge I am not an expert and I welcome any constructive feedback in order to refine the guide and make it as useful as possible to everyone.

Safe travels.