A Super Simple AWESOME Off Grid 12V System... Step By Step With Diagrams

Updated: Oct 24, 2021

Hey everybody, so we had a lot of comments that our last full system set up was a bit over the top for most peoples needs and to be fair it was all singing all dancing. Another complaint we had was that is looked really complicated however we are just going to put that down to people on facebook just looking at the post thumbnail rather than reading the post as we have been told by far more people how awesome and easy to to follow it was.

The set up was aimed at full time van lifers who wanted all of the luxuries of a home but in a van and we think we smashed it.

If you haven't seen it yet take a look it might be exactly the sort of thing you want for your van conversion, it is in four parts but all are available to see on our blog now. This is part one...

So we have decided to reply to the comments with a totally awesome but super simple fully off grid set up that we hope will be an awesome solution for many of you.

We hope you all find it helpful...

The first thing you are going to need to be off grid is somewhere to store your energy and for that we use a battery, for this set up we are going to recommend an AGM (absorbent glass mat) battery.

AGM batteries are perfect for Vans as they are sealed so there will be no dangerous fumes leaking into your van whilst you are sleeping at night.

This battery is quite expensive but literally one of the best AGM batteries on the market anywhere in the world, at its recommended 50% depth of discharge it will give you 1400 cycles (and probably a lot more).

Rolls S12-290AGM Deep Cycle Series 12 Volt Battery



As we mentioned above these batteries are quite expensive, but they are the best AGM batteries on the market in our opinion and they store about three times more power than your average leisure battery. However if this battery is too expensive for you check this post out for a few more good options...

This battery will give you 260AH @ a 20 hour rate of discharge however don't forget that you should only discharge an AGM battery to about 50% of its capacity so in actual fact this battery will give you 130AH of useable power. Please see picture below...

Leisure batteries are very easy to install and basically they just need securing into place so they do not move when you're driving and then you need to earth them somewhere on your vans chassis.

To do this you will need a cable and some lugs, when it comes to batteries that have the ability to supply very high amps all at once it is always best to be safe rather than sorry and over size your cables so they have no chance of getting hot and starting a fire.

It is also a very good idea to run the shortest length of cable possible to each and every component in your build for the same reason as above and to minimise volt drop.

With that being said to earth your battery to your chassis we recommend using 50mm2 cable.

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All Trade Direct 1M Metre Black Battery Starter 50Mm2 Cable Kit Car Van Truck Marine 240A 240 Amps



SELTERM 50 mm² M10 Hole UL Marine Grade Wire Lugs, Battery Cable Ends, Tinned Copper Eyelets, Tubular Ring Terminal Connectors [B68] - 15 Pack



Building your battery cables yourself at home will save you lots of money and is very simple to do, first you remove just enough of the cable sleeve to fit securely into you lugs. Please see picture below...

Next you need to securely crimp it into place however these things are huge and quite solid so you will need a specific tool for the job or improvise with a hammer and punch. We suggest using the correct tool for the job. Basically you put your cable and lug in it, whack it with a hammer and it is done...

Draper 64335 Battery Terminal Crimping Tool


To earth your battery bank you need to either find an earthing point that is already there or make your own, it saves a little bit of time if you already have an earthing point near where you want to install your battery bank but it only takes about a minute to make your own.

To find one that is already there you just need to find somewhere on your vans chassis that already has a bolt in it, the most common places to find them in the back of a panel van would be near your light clusters where your lights have been grounded but they are usually quite hight up.

To make your own drill a hole into a bit of your interior bodywork that is connected directly to your chassis, remove all the paint from the area around the hole with a grinder or some sand paper so it is bare metal, pop a bolt through the hole, attach the earthing cable, screw a nut onto the bolt and you are done.

So first take your 50mm2 black earth cable and securely crimp a lug to each end, then bolt one end to the negative - terminal of your battery. Next take the other end and bolt it to your chassis earthing point and you should have something that looks like this...

The next thing we are going to add to this set up is an awesome bit of technology called a SOC (state of charge) shunt that will let you accurately monitor the state of charge of your battery in a few different ways, we need to attach this to the negative battery terminal before we attach anything else so now is the perfect time to do it

For this you will need...

Renogy 500A Battery Monitor



All Trade Direct 1M Metre Black Battery Starter 50Mm2 Cable Kit Car Van Truck Marine 240A 240 Amps



Once you have the bits above you are ready to install it, so first take your 50mm2 cable and cause 30cm off of one end so you are left with two cables, one short (30cm) and one long (70cm)

Take the small 30cm length and just like before securely crimp a 50mm2 M10 cable lug to each end. You should have some of these left from the pack I recommended earlier. Please see picture below...

Next bolt one end directly to your negative terminal of your leisure battery.

please see picture below.

Once you have done that you will need to find the 500 amp shunt that will have come with your Renogy battery monitor and connect the B - (battery side) to the cable.