This is a 12v & 220v power supply with a solar and mains charger and a remote to activate the outputs. The remote came as an addition as it makes things so much easier to press a button in your pocket and have lights on in your camp site.

Step 1: The Goal

I love camping and the outdoors but also like having my gadgets with me and comforts like lighting in the evenings.
I wanted a universal power supply that would come in handy while away from any form of power. I complicated this quite a bit a first but have now posted what I had done when I opened it up to make some changes to the unit.
This unit provides 12v from 3 x7ah batteries and that is used to run the led lighting that we use around the camp site and charge our cell phones and iPads. I installed a 150w inverter into the box too making it more versatile and because I had a little inverter lying around

Step 2: The Beginning

I started with steel box that I had lying around in the garage and had a look to see what I could fit into it.
I had an led voltage indicator kit lying around so that was the first thing that was thrown in.
The next was the little inverter that was under my work bench that was never used because it was modified sine wave and only 150w.
I had a few lead acid 7a/h batteries lying around too that had to go in it was just a challenge to see if I could fit 3 of them.

Step 3: The Outputs

I installed 4 toggle switches so that I had four separate switched outputs so I could choose what I wanted on. For the remote to work all the outputs but not interfere with the on/off states of the toggle switches I put diodes on each of the inputs from the remote receiver unit and connected that to the 4 12v output connectors.

Step 4: Inputs and Extra Outputs

I wanted to be able to connect an extra battery to the unit for extra power or be able to connect something that would need more current than the 4 output connectors would deal with so I installed these and they were also used to connect everything together.

Step 5: The Inverter

The inverter was a simple one using a toroidal transformer to step-up the voltage
I just took the whole circuit and installed it into the box. I had to make a small PC board for the indicator LEDs, but other than that I kept it simple. It gets 12v from the batteries and inverts it to 220v that is available when switched on.
I also put a 230v meter to show when the inverter is on or if there is a problem.
The meter is connected to the output of the inverter

Step 6: Solar Controller and Trickle Charging

I use a 50w solar panel that we take camping with us that is sufficient to charge the batteries with the amount that we use for lighting, fans and charging devices but if we needed I could also use a 90w panel that I have sitting around. The solar controller is a small pre-constructed unit that I bought for about R200.00 it nothing fancy like an MPPT but it does the job not over charging the batteries. Because it's a simple charger I also installed a small 12v transformer with a rectifier circuit to trickle charge and hold the batteries at float voltage while the unit is not being used.

Step 7: Connecting the Batteries

The 3 batteries are connected in parallel to make a 20amp/hour supply. This is not a lot and will not run the inverter for you to watch tv the whole night but it's nice to have for a quick 220v emergency.
The batteries are connected via a fuse to two spade terminals that I installed. The fuse is important as you can burn your wiring if you short something out.

Step 8: The Remote Switch

I put the remote receiver on top of the batteries and this is connected via a switch to the 12v. I have made it switchable so that it does not drain the batteries when the unit is not being used.
I love the feature this gives us.
We can leave the campsite and go and take a sundowner cruise on the boat and when approaching the campsite just turn all the lights on at the press of a button so you are not fumbling in the dark

Step 9: Closing Up.

Everything needs to fit inside and that took some planing. The inverter, solar controller and transformer were all installed behind the batteries. I cable tied everything so that there was minimal movement inside while we were traveling to and from the places where we camp.
Make sure you have good connections and use insulation and solder when needed.

Step 10: The Completed Project

Here is the unit with all the extras that go with it when we are camping.
This includes-
The 50w solar panel
Led light strips for the tent and gazebo
12v fan (that is appreciated hectically on hot days)
Ultrasonic generator to chase away bugs ( I still think Tabard works better)
A 12v cigarette lighter adapter for things like iPhone charges and other small 12v powered devices.

Step 11: Being Used

Here is a photo of our last campsite at Mansfield game reserve up the Kowie River

We have used the unit every time we have gone camping since I made it and that was about 3 years ago.

I will hopefully get more into detail on my next instructable but feel free to ask me any questions or make any comments.

I love this website and have the app on my ipad and iPhone

Chris Davidge