A Step By Step Guide To An Awesome Powerful Fully Off Grid 12v Set Up

Updated: Jun 1




Hi everybody, we are back again with another full set up and today we have an awesome one for you.


If you don't know anything about 12v electrics it can be a very confusing but it is something you are going to need to get right first time round so you can move on with your build. In this post we are going to try and make the a lot easier for you without the need of watching endless youtube videos that only cover bits of what you need to know and just post everything here in one post...


This is not going to be one of our budget posts where we try and keep everything to a bare minimum but as usual we will try our hardest to keep the costs as low as possible and everything as simple as possible, although we will add luxuries as most people want them.


We will include everything you need from start to finish including all devices, accessories, cables, fuses, switches, outlets, batteries, chargers, controllers, solar etc.


So here is our...


Step By Step Guide To An Awesome Powerful Fully Off Grid 12v Set Up



The first thing we want our 12v set up to be capable of is being off grid all year round without the need for a hook up. For this will will need a decent amount of power storage (batteries) and a way to keep the charged up. So I will start with leisure batteries.








For this set up I would go for three of these 100ah Photonic Universe AGM batteries, that will give you 150ah of useable power





12V 100AH Platinum AGM Deep Cycle Leisure Marine Battery







https://ebay.us/fo9xz3






FOR SOME MORE AWESOME AGM BATTERIES PROPERLY PLEASE CHECK OUT OUR NEW BLOG POST...






The next thing you will need is some cable to join your batteries together in parallel to turn it from 3x 100ah batteries to 1 x 300ah battery bank, for this you will need 2 x positive cable and 2 x negative cables, As an amazon associate I earn from qualifying purchases



30cm 50mm2 heavy duty red battery cable link with eyelets to connect batteries together in one battery bank


YOU WILL NEED X 2 OF THESE



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30cm 50mm2 heavy duty black battery cable link with eyelets to connect batteries together in one battery bank


YOU WILL NEED X 2 OF THESE



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Joining 3 batteries in parallel is very simple, you just join the positives to the positives to the positives, and negatives to the negatives and it is as simple as that. Please see below...


The final thing you will need to finish your battery install is another negative cable to earth your battery bank, you should try and find or make your own earthing point as close to the battery bank as possible, for this you should use one of these cables.




Battery Inter-Connecting Cable - 50mm Cable With M10 - M10 Lugs - 50cm



CLICK HERE TO BUY FROM BIMBLE SOLAR



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 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.


Now you have your batteries installed you will need a way to keep them charged, so the next things we will add to this set up is solar.


For a powerful set up that can be used off grid all year round you really need to fit as much solar on your roof as possible, if you have a smaller van like a MWB (medium wheel base) then you are going to struggle to fit enough solar on your roof to get you through the winter.


This set up would be an ideal size for a LWB OR XLWB (Long wheel base or extra long wheel base) vans however instead of writing a separate post for a MWB van anything that wouldn't be suitable for a MWB van we will let you know and post a link to what you need instead in green and we will post the wiring diagram on our facebook and instagram pages.


So as we want to fit as much solar as possible for this set up I am going to recommend 3 x 200w solar panels giving us 600w of solar, we could have just gone for 2 x 300w solar panels but with 3 x 200w then there is normally still space for 2 x roof fans/skylights etc and most people want them too.


These panels are good quality, a decent size and are strong enough to charge 12v & 24v battery banks, this means later on we can tweek the settings in the solar MPPT controller for a better charge on cloudy days etc.



200W Photonic Universe monocrystalline solar panel for charging 12V or 24V batteries in a motorhome, boat or yacht, or off-grid


LWB OR XLWB YOU WILL NEED X 3 OF THESE

MWB YOU WILL NEED X 2 OF THESE



https://amzn.to/3183hDP



The next thing you will need is some inline fuses, we have 3 x 200w solar panels and a 12v battery bank 200W ÷ 12V = 16.6AMPS so we round up to 20 AMPS. So we will need 3 x 20 amp inline fuses.



Renogy 20Amp 1000VDC Male to Female PV Solar Panel MC4 Connector Waterproof In-Line Fuse Holder w/Fuse 20A


LWB OR XLWB YOU WILL NEED X 3 OF THESE

MWB YOU WILL NEED X 2 OF THESE



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These inline fuses need to be attached to the positive cable coming off of each solar panel, they just clip on and it couldn't really be any simpler. Please see picture below...





Once your inline fuses are clipped into place and you are safe from any unwanted power surges frying your cables, equipment and van we need to join them all together so that we only have one cable going through your roof and into your solar charge controller.


For that you are going to need a pair of Y-Branch connectors.



ANFIL T-type MC4 Branch Cable Connectors


LWB OR XLWB YOU WILL NEED 1 SET OF THESE

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MWB YOU WILL NEED 1 SET OF THESE

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Again these couldn't be easier to install you just clip all of the inline fuses into the positive Y-Branch and the connectors on the end of all your negative cables into the negative Y-Branch connector, please see the photo below...




The next thing you will need is some solar cable to run from your Y-Branch connectors to your solar charge controller, as we have 3 x 200w solar panels all running into one we need some cables thick enough for the increase in amps.


600w ÷ 12v = 50amps


So for this job I recommend these cables




ANFIL 3M/10 Feet 10AWG Solar Panel Extension Cable with MC4 Female and Male Connectors (10FT Red + 10FT Black)


YOU WILL NEED ONE SET OF THESE



https://amzn.to/3fDyFR5




These cables are three meters long so to avoid having to buy any extra cable it is important to join these cables to your Y-Branch connectors as close to where you are going to drill through your roof so you can get the cables into the back of your van and you should drill that hole as close to where you are going to have the solar charge controller as possible.


To connect these cables to your Y-Branch connectors simply connect the red cable to the positive connector and the black cable to the negative connector, please see picture below...

As I mentioned above now you have your solar cables connected then you are going to need to get the cables through your van roof into the back of your van, to do this you need to get yourself a waterproof dual gland box, drill two holes in your roof, pop some grommets in the holes, feed your cables through the glands and the holes and then secure the gland box to your roof with sikalex



Offgridtec Roof Duct Dual



BLACK - https://amzn.to/315OHg8


WHITE - https://amzn.to/2GPzGbz






Rubber Grommet Assortment Kit Electrical Conductor Gasket Ring Set for Wire, Plug and Cable, 180 Pieces




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Sikaflex 522 Caravan Adhesive & Sealant for Caravans, Motor Homes & Trailers






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Once you have your cables through your roof into the back of your van the next thing you are going to need is a solar charge controller, there are two different types PWM (Pulse Width Modulation) or MPPT (Maximum Power Point Tracker)


For this set up as we recommend a MPPT charge controller for the best charge performance with the panels above.


To decide what size charge controller we need we just have to look back at the maths we did before


600w ÷ 12v = 50amps


So as we have 600w of solar and a 12v battery bank we are going to need a 50amp MPPT solar charge controller



EPEVER MPPT Solar Charge Controller 50A Negative Ground 150V PV Solar Panel Charger with MT50 Remote Meter


LWB XLWB YOU WILL NEED THIS

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MWB YOU WILL NEED THIS

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*****************************************

FOR A WIFI BLUETOOTH ADAPTER FOR THIS PLEASE CHECK OUT OUR ADDED EXTRAS & UPGRADES POST



It is very important that you DO NOT connect your solar panels to your solar charge controller before you have connected your solar charge controller to your battery bank (leisure battery bank) so that is our next job.


For this we will need some more cables, some lugs and another inline fuse.


TUOFENG 10 Gauge Electrical Cable 10 AWG Silicone Wire Hook Up Wire Cable [3 m Black and 3 m Red]



YOU WILL NEED 1 X SET OF THESE


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The first thing you need to do with these cables is connect some lugs to them, you will need 1 x lug for the black (negative) cable so you can attach it to the battery and 3 x lugs for the red (positive) so you can connect it to the inline fuse holder and the battery.


My suggestion for lugs is to get a decent assortment box as you will get through lots and they always come in handy and the fuse holders never seem to have the same size bolt fittings as battery terminals so it is best to have a selection when it comes to an unusual fitting.



Glarks 105Pcs 12 Type Heavy Duty Lugs Battery Cable Tinned Copper Eyelets Tubular SC Ring Terminals Connectors with Spy Hole Assortment Kit



YOU WILL NEED 1 X SET OF THESE


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The negative cable is the easiest so start there, just connect a lug with a big enough hole in it to fit onto your bus bar bolt (8mm) to one end of your black cable and crimp securely into place.





Next take the positive cable (red) and cut it about 20 cm (8 inches) from one end, now take the small 20cm piece and attach a lug on one end of it that is big enough to fit on your bus bar terminal bolt just like you did above with the black cable.


On the other end of the small 20cm piece attach another lug but this one has to be small enough to fit into your fuse holder so you can close the lid... You will find a suitable lug in the selection box.


Next attach an identical lug to the end of the longer piece of positive (red) cable as this will also be attached to your inline fuse holder.



All Trade Direct 1 X Strip Link & Midi Fuse Holder For Striplink & Midi Fuses Fuseholder Fits All


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All Trade Direct 2 X 60 Amp Midi Fuse High Current All Midi Amps 40-150Amp & Fuseholder Stocked



YOU WILL NEED 1 X OF THESE



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Once you have all the lugs on your positive cable put the fuse into the fuse holder and attach the cables to the fuse holder, please see below.




Now the cables are sorted it is time to connect your batteries to your solar charge controller, before we do that we are going to need some bus bars.


Bus bars will help you keep all of your cables neat and short and also save you from having to run every single cable back to your battery bank.




T Tocas 300A BusBar Box - Heavy-Duty Module Design Power Distribution Block with 4 x M8 Terminal Studs



YOU WILL NEED 2 X OF THESE



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You will also need two more cables and lugs to connect your bus bars to your battery bank, these will need to be really thick as they will be carrying a lot of power.


For this I recommend using these cables & lugs



All Trade Direct 1M Metre Red Battery Starter 50Mm Cable Kit Car Van Truck Marine 345A 345 Amps



YOU WILL NEED 1 X METER OF THIS



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All Trade Direct 1M Metre Black Battery Starter 50Mm Cable Kit Car Van Truck Marine 345A 345 Amps



YOU WILL NEED 1 X METER OF THIS



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COPPER TUBE TERMINAL CABLE LUGS BATTERY WELDING 50MM² CABLE x 10MM HOLE x 10


YOU WILL NEED 1 X SET OF THESE


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To connect your bus bars to your battery bank first take the positive cable and one of the lugs above onto each end and crimp into place then do the same with the negative cable.


Once you have done that take the positive (red) cable and wire one end to any of the studs on one of your bas bars and the other end to the positive battery terminal on the first battery in your battery bank... Please see photo below.

Next take the negative (black) cable and connect one end to any stud of your remaining bus bar and then bolt the other end directly to the negative terminal on the last battery in your battery bank... Please see picture below

Now you are ready to connect your bus bars to your charge controller and this is very simple to do.


First take the positive (red) cable with the inline fuse already wired into it and bolt the end with the cable lug on it directly to one of the spare studs on your positive bus bar then wire the other end to the + next to the battery symbol on the bottom of your solar charge controller.


Then take your negative cable and bolt the end with the lug directly to your negative bus bar and wire the other end to the - next to the battery symbol on the bottom of your solar charge controller.

To find the holes in the 50 amp controller you will need to remove the casing at the bottom to reveal lots of ports and connections for your cables... please see picture below



You can now connect your solar panel cables to your solar charge controller, again this is simple just look for the solar panel symbol on the charge controller and attach positive (red) to the + and negative (black) to the minus -



🥳 -Congratulations you now have an awesome powerful set up that will power you off grid all summer long 🥳


And it couldn't really have been any simpler 🤩


You should now have something that looks something like this... Don't worry it's not to scale




As I said above you are all good to go now for the summer however we want this set up to be able to power us off grid all year round.


In the summer when the days are long and the sun is high in the sky solar is amazing and you won't need anything else, each 100w of solar will top your batteries up by about 55ah on a sunny day in summer, with this set up there is 600w of solar and 225ah of useable power so 6 x 55 = 330ah in one day.


Yeah that is overkill and that is why you now have pretty much endless power in the summer however on a sunny day in the winter 100w of solar will only top your batteries up by about 8.5ah so your 600w of solar would only give you 51ah of charge and for your 225ah of useable power this is nowhere near enough.


So for winter we have to add another charging option and the best thing for this job is a B2B charger (DC-DC, battery to battery).


For this set up I recommend this one



Sterling Power 12v 60amp Battery to Battery Charger BB1260



https://amzn.to/3k4aT1N


As you have a large battery bank and you want to be off grid all year round then a 60 amp B2B charger is perfect for this set up, the lower the amps of the charger = more hours driving to top up your batteries.


B2B chargers are quite new technology and are now pretty much taking over from split charge relays/vsr/split chargers. They are wired up pretty much exactly the same as a split charge relay but work completely differently, with split charge relays your alternator charges your vans starter battery until it is sufficiently charged then the relay senses that it if charged and then diverts the power from your alternator to charge your leisure batteries.


The problem with this is when your split charger thinks that your battery is charged it stops putting charge into either of your batteries but when batteries have been off of charge for a couple of hours they settle so what a split charge relay thinks is fully charged is actually only about 80% cha