A Super Simple AWESOME Off Grid 12V System... Step By Step With Diagrams PART 2

Updated: Jun 16





Hi everybody and welcome to PART 2 of our awesome set up, if you are just joining us at PART 2 and have not seen PART 1 of our post please follow the link below to so you can see how we got to this point.





If you have read PART 1 already We are just going to jump straight into this by adding the solar.


At the moment you should have something that looks like this...



At the end of PART 1 I left you with these two paragraphs...


You might have noticed that I just wrote all summer long and that was on purpose as solar is pretty useless in the winter with the long nights and bad weather so to be off grid all year round we are going to need something to be able to efficiently charge your batteries in the winter too.


So the next thing we are going to add to this set up is a B2B charger..


So lets move on to PART 2...


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 however on a sunny day in the winter 100w of solar will only top your batteries up by about 8.5ah and 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


As an amazon associate I earn from qualifying purchases



Sterling Power 12v 60amp Battery to Battery Charger BB1260



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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.


Our battery has a maximum charging rate of 92amps and we have 30.5amps of that coming from our solar set up (365w panel ÷ 12v battery = 30.416) so that gives us 61.5 amps left over. 60 amps is the closest we can get to that and in the winter every amp counts.


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% charged.


B2B Chargers are much more intelligent, they alternator keeps charging your starter battery and then your starter battery powers your smart charging unit to charge your batteries and can charge them up to 99% of capacity.


So to wire your B2B charger to your starter battery, van and leisure batteries you are going to need some more cables and inline fuses.


Red Battery Starter/Welding Flexible PVC Cable Wire 110 Amp 16mm MKGT® (16mm² Red, 10 Meters)



YOU WILL NEED UPTO 10 X METERS OF THIS

(please see below)




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Black Battery Starter/Welding Flexible PVC Cable Wire 110 Amp 16mm MKGT® (16mm² Black, 1 Meter)



YOU WILL NEED 1 X METER OF THIS




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All Trade Direct 2 X Strip Link & Midi Fuse Holder For Striplink & Midi Fuses Fuseholder Fits All



YOU WILL NEED 1 X SET OF THESE



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All Trade Direct 2 X 100 Amp Midi Fuse High Current All Midi Amps 40-150Amp & Fuseholder Stocked



YOU WILL NEED 1 X SET OF THESE



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Once you have all of the bits above then we can start to wire the B2B charger to your starter and leisure batteries, first we have to make some more cables up.


So find the positive (red) 16mm2 cable and off of one end cut yourself 3 short lengths


2 x 20cm lengths

1 x 30cm length


First take your 30 cm length and on one end attach a 16mm2 M6 (6m) lug and on the other end

attach a 16mm2 M8 (8mm) lug and crimp both securely into place.


Next take 1 x 20 cm lengths and attach a 16mm2 M6 (6mm) on to one end of it..


With the last 1 x 20 cm length and on one end attach a 16mm2 M6 (6m) lug and on the other end attach a 16mm2 M8 (8mm) lug and crimp both securely into place.


Please see picture below...




Next find your negative (black) 16mm2 cable and cut yourself a 50cm length.


On one end attach a 16mm2 M8 (8mm) lug and crimp securely into place, please see picture below...


First put one of you 100 amp midi fuses into one of your midi fuse holders.


Then take your 20 cm length of positive (red) 16mm2 cable with a M6 (6mm) lug on one end and nothing on the other end and bolt the lug on to either side on the midi fuse holder.


Next take your 30 cm length of positive (red) 16mm2 cable with a M6 (6mm) lug on one end and an M8 (8mm) lug on the other end and bolt the M6 (6mm) lug to to other side of the fuse midi fuse holder.


Please see picture below...

Next take the end of the 20 cm length without a lug on the end strip enough insulation off of the end and wire it directly to the + out terminal on the bottom of your B2B charger. (number 3 in the picture below)...





Now bolt the end of the 30 length with the M8 (8mm) log on it to any spare terminal on the same bus bar as your solar MPPT controller.


Please see picture below...






Next take your 50 cm length of negative (black) 16mm2 cable with a M8 (8mm) lug on one end of it.


Strip some insulation from the end without a lug attached and wire it directly to the negative terminal on your B2B charger (number 4 on the picture below)...




You should now have something that looks like this...






Next you need to find your long length of 16mm2 positive (red) cable. You should have had 10 x meters to start with but you cut 2 x 20 cm pieces and 1 x 30cm piece off so it should be just over 9 meters long.


Again as with everything in this post it is best to keep all cables as short as possible for safety and to minimise volt drop.


Hopefully you will only need a few meters of this cable but depending on the route you take to your battery and the length of your vehicle you might need more.


First take your long length of 16mm2 positive (red) cable and strip some insulation off of one end


Next wire that end directly to the + in terminal on your B2B charger (number 5 in the picture below)...



Next neatly run your long length of positive (red)16mm2 from your B2B charger through your van to your starter battery. This will depend on your van some are under the bonnet, some are under seats some are in footwells so you will need to find yours and a decent route to it.


Remember this cable carries a lot of AMPS it needs to be protected from the body work and getting damaged, it is best to run it through conduit and also rubber grommets wherever it passes through any sharp body work as the last thing you want is the bare insides of the positive cable touching anything metal whilst it is a live circuit.


When you have run your cable from your B2B charger to within a few inches of your vans starter battery cut any extra cable off (we will use this later) and crimp a 16mm2 M6 (6mm) lug on to the end


Next find your last remaining 20 cm length of 16mm2 positive (red) cable with a M8 (8mm) lug on one end and a M6 (6mm) lug on the other end, a midi fuse holder and a 100 amp midi fuse.


Put your 100 amp midi fuse into the midi fuse holder


Take the cable that comes from your B2B charger and bolt the lug to any side of the midi fuse holder


Then take your 20 cm length and bolt the M6 (6mm) lug to any side of the midi fuse holder...

And finally to finish the install of your B2B charger connect the M6 6mm lug from the 20 cm cable to the positive terminal of your starter battery.


Please see picture below...


Congratulations 🥳🥳🥳🥳


You now have an awesome off grid self charging set up that can keep you powered all year round, no matter how many daylight hours you have or how bad the weather gets and that is pretty awesome.


We have left a spare terminal on the bus bars that your MPPT & B2B chargers are connected to, this is so you can add a 240v onboard charger if you wish to do so. we have not chosen to add one to this set up as it is an off grid set up however if you're planning on staying in lots of campsites with hook up points and want extra power capacity an onboard battery charger with a hook up point kit is what you need. We will be making a video on this very soon so don't forget to subscribe to our youtube channel to see it when it is ready, LINKS AT THE BOTTOM ON THE PAGE


Now it is time to add everything that will run off of our system.


As you might have noticed from your vans built in fuse box and from our set up so far that every single circuit need to be fused for safety.


So to keep things neat and tidy and easy to keep track of the best option is to add a blade fuse box and then run all of your little bits and pieces to and from the fuse box.



So for this we recommend one of these...




MICTUNING Fuse Box,12 Way Blade Fuse Box with LED Indicator for Automotive Car Boat Marine SUV RV Van…



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



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All Trade Direct 2 X 100 Amp Midi Fuse




YOU WILL NEED 1 X SET OF THESE



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Mirocle Life Battery Disconnect Isolator Switch 12V 24V 48V 60V Waterproof Cut Off Kill Switch







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You should have 50 cm of positive (red) & 50 cm of negative (black) 16mm2 cable and some 16mm2 M6 (6mm) cable lugs left over from your MPPT & B2B install but just incase you don't...





Red Battery/Starter/ Flexible PVC Cable Wire 110 Amp 16mm by MKGT® (16mm² Red, 1 Meter)



YOU WILL NEED 1 X METER OF THIS




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Black Battery/Starter/ Flexible PVC Cable Wire 110 Amp 16mm by MKGT® (16mm² black, 1 Meter)



YOU WILL NEED 1 X METER OF THIS




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Cable Lug 16mm2 M6 20x Cable Shoe






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First take your 1 x meter of positive (red)16mm2 cable and cut yourself 2 x 20 lengths.


On the fist length attach a 16mm2 M8 (8mm) lug on to one end and a 16mm2 M6 (6mm) lug on to the other end the securely crimp into both place


On the second length attach a 16mm2 M6 (6mm) lug on to one end and a 16mm2 M10 (10mm) lug on to the other end and securely crimp both into place.


Please see picture below...






Next put a 100 amp midi fuse into a midi fuse holder and attach the M6 (6mm) lug from each cable to either end on the midi fuse holder.


Please see picture below... (pay no attention to the cable lengths in the picture below they should be equal 20cm lengths)



Now take the end with the M8 (8mm) lug on the end of it and bolt it directly to any spare terminal on your empty positive bus bar.



Please see picture below...





Next find your isolator switch and attach the M10 (10mm) lug on the cable coming from your midi fuse to either of the terminals and securely bolt into place.



Please see picture below...


As you started with 1 x meter of 16mm2 positive (red) cable and cut 2 x 20 cm lengths off you should have a 60 cm length left over.


Take that 60cm length and on one end attach a 16mm2 M10 (10mm lug on to one end and a 16mm2 M6 (6mm) lug on to the other end and securely crimp both into place.


Fist attach the M10 (10mm) lug on to the last remaining terminal on the back of your isolator switch and bolt into place.


Please see picture below...

Next take the M6 (6mm) lug and attach it to the positive (top) terminal on your 12 way blade fuse box.


Please see picture below...



And to finish off your fuse box installation take 1 x meter of 16mm2 negative (black) cable and attach a 16mm2 M8 (8mm) lug on to one end and a 16mm2 M6 (6mm) lug on to the other end and crimp both securely into place.


Attach the end with the M6 (6mm) lug to the negative (bottom) terminal on the 12 way blade fuse box and bolt securely into place.


And finally attach the other end with the M8 (8mm) lug to any terminal on your empty negative bus bar.


Please see picture below...




Now we have installed the fuse box we are going to zoom in on the diagram for a bit to make things easier to understand.




The first thing that everybody needs in a camper van is lights and to keep everything as simple for your install as possible for your ceiling lights we recommend touch sensitive lights, these are much easier to wire up than ones that need switches as you can wire them directly to your fuse box and not have to go via a switch.


This means if you want to turn a light on and off you just have to reach up and touch it.



8 X 12V LED TOUCH SENSITIVE ON OFF LIGHT BOAT CARAVAN MOTORHOME BRUSHED WARM


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As these are such low powered lights we could wire them all together into one circuit however if you have a problem with that one circuit whilst you are out and about you will be left without any lights, it is best to wire them together in two circuits so if something goes wrong with one circuit whilst you are in it you have another for back up.


I know this sounds complicated but don't worry it really isn't. You will need a few more bits to do this... please see links below



WAGO 221-412 x10, 221-413 x10, 221-415 x10 of Each Splicing Connector Conductors 0.14-4 mm². Compact Design with Lever


YOU WILL NEED 1 X SET OF THESE


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*11 AMP Rated* 0.5mm2 Thin Wall 2 Twin Core Cable Wire Car LED Lights (30M Roll)


YOU WILL NEED ONE ROLL OF THIS (YOU WILL HAVE SOME LEFT OVER FOR OTHER BITS)



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H&S Crimp Connectors 520pcs Electrical Connectors Assorted Insulated Crimp Terminals Kit Pack Spade Bullet Butt Fork Wire Connectors



YOU WILL NEED ONE PACK OF THESE



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So to wire these together into two separate circuits you will need to use 4 x lights for each circuit


First take 4 lights and take the positive cable from each light and wire them to one of your Wago 221 connectors with 5 x terminals... please see picture below




Next take some of your 11 amp twin core cable and remove enough of the outer layer of insulation to reveal enough red and black cable and connect the positive (red) cable to the Wago 221 connector that you wired your lights to... Please see picture below






Once you have done that run all of the negative cable from each light and connect the to another Wago 221 connector along with the negative (black) cable from your twin core cable... please see picture below.






Now run the twin core cable neatly to your 12 way fuse box and cut to size.


When you have cut enough cable to reach your fuse box strip the ends off of the both the positive and negative cables and crimp one of these connectors on the end of each.



Now you can connect them to your 12 way fuse box, first take the positive (red) cable, attach it to any of the positive terminals on your blade fuse box and screw into place.


Next take the negative (black) cable and attach it to any negative terminal on the blade fuse box and screw into place.


As you are wanting two circuits for your lights repeat the same process again with the remaining four lights.


You should now have something that looks like this...





To finish off the down lights the last thing you will need is some blade fuses.


These lights are very low powered at 1.8 watts per light, this is a very low power draw and will only need a small fuse, the exact maths is


4 x 1.8 watts = 7.2 watts

7.2 watts ÷12 volts = 0.6 amps


So in theory if a 1 amp fuse would be enough for each circuit but the cable is 11 amp so anywhere between 1 amp and 10 amp would be suitable.


I like to go for something like a 3 amp of 5 amp but as long as it is over 1 amp and under 11 amp you are good to go


Standard Fuses,TKING 100pcs Assorted Auto Car Standard Blade Fuses Replacement Kit 2A 3A 5A 7.5A 10A 15A 20A 25A 30A 35A With 1 Fuse Extrator 1 Carrying Box (Car Standard Blade Fuse)


YOU WILL NEED A SELECTION OF BLADE FUSES

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Please see picture below...





The next thing you are going to need is some 12v sockets, both the cigarette lighter style and some usb sockets, before we get on to our awesome charging sockets set up we are going to need a few normal ones for powering some of your every day bits.


There are a few bits in your van that are going to want to leave plugged in pretty much all of the time and these 2 x sockets will cover two of them... your fridge & TV.


It is best to have dedicated sockets for both of these items so you never have to choose between what you can use at certain times and because they are dedicated sockets you already know exactly where they should go. As close to where you are going to have you TV & Fridge as possible!


For this you will need...


Universal Waterproof 12V-24V DC Cigarette Lighter Socket For Car Boat Motorcycle (2 Pack)


YOU WILL NEED 1 X SET OF THESE



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When it comes to wiring these sockets into your set up you are going to need some higher amp rated cable.




*21 AMP Rated* 1.5mm2 Thin Wall 2 Twin Core Cable Wire Car LED Lights (30M Roll)



YOU WILL NEED 1 X ROLL OF THIS


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So first run a length of 21 amp twin core from your 12 way fuse box to where your fridge will be located.


Then run a length of 21 amp twin core from your 12 way fuse box to where your TV will be located.


Next attach some female spade crimp connectors to one end on both the positive (red) and negative (black) cables on both your lengths of 21 amp twin core cable... Please see picture below.





Next take both of your cigarette lighter sockets and attach the positive (red) cables to the positive (+) prongs on the back of each socket and the negative (black) cable to the negative (-) prongs on the back of each socket... Please see picture below




Now find the cable that we ran from the fridge to the 12 way fuse box and on the other end just like we did before with the 6 way fuse box attach a ring crimp connector to both the positive (red) cable and the negative (black) cable.


Then screw the positive (red) cable onto any of the positive (+) terminals and the negative (black) cable onto any of your negative (-) terminals on your 12 way fuse box.


Repeat again with the cable that you ran from your TV to your 12 way fuse box and you should have something that looks like this...