Camping conversions!

I admire your knowledge and expertise with electrics , but what if anything is wrong with mine as follows

Standard alternator engine battery, 130 amphr house battery fed by voltage sensing relay fridge 12v fed by sensing relay only runs when engine running , 130 watt solar panel with regulator for house battery, all with appropriate fuses, switch board with circuit fuses to isolate any faulty appliances all lights are led and tv low wattage. Never run out of power yet and never had a flat starter battery.

Your layout sounds good, 120W solar is the key to your never running out I think - plus that huge 130Ah battery!!

Mine is a prototype or Mk 1, V1.0 etc. it remains to be seen if it works well at all!
Unusually for a camper mine is a very 230V focussed system and that's really why it's complex.

Were I to do it to another van I'd make up the custom B2B system on a separate panel and just fit it as a separate part as it's quite fiddly with the split charge sensor, 2 relays, 2 DC-DC converters (for bi-directional charging) etc. Best made up on the bench and merely connected in now I know what it needs. This is really the only complex part, it simply takes earth, 12V, 24V - just three connections, but no one makes such a converter - or at least I didn't fine one!!

My custom 12V+24V B2B means the van battery is still used for all the usual stuff like the radio, dome lamps etc so that wiring can all be left alone. Essentially all it does is look at what battery system is being charged and float charge the other one. The Victron or MPPT does the full multi-stage charging as required.

The design also makes the solar charging a very simple single battery one, any battery can in fact be charged and the whole system will charge.

The 230V is useful of course for off-grid charging of stuff but it's main job is to run the £70 A++ rated 230V 'tabletop' compressor fridge, the cheapness of which pays for all the other electrics. I also tend to use 230V quite a bit with my gadgets so having it in a van makes it much more homely

I get the idea of using a 240v fridge there are cheap as chips but they are all compressors that is why we went to the expense of a three way fridge, had a 12v compressor and never was silent in a small van very annoying , it seams a lot of trouble to get 240v as most things can be charged from 12v these days you can even get 12v hair dryers but things like electric BBQs or fryers or anything using heat is going to drain your batteries pretty quick . However GPW your ingenuity does impress keep us informed on how it performs.

The drawback of the compressor is as you noted - the compressor LOL. I'm hoping it will be fairly quiet or I'll have to switch it off at night! At least the back of it faces the back of the drivers seat so hopefully it will be ok.

The advantage of 240V is for cameras, laptops, shavers, toothbrushes etc I don't have to change anything and can run power tools, Lipo chargers etc. from it if needed (but only small ones LOL). The inverter is only 500VA so not up to hairdryers etc unless we are on hookup.

The key thing in the van is going to be packaging the loo, fridge, seating, sleeping and storage which should be started before too long! I'm hoping it all fits LOL.

Stealth hookup going in, finally wired up the socket for the van, just waiting for some nylon P clips for the inside.
The socket can't be seen in normal use, I'm hoping it's protected from the elements by the spare wheel and is routed through 3/8" fuel tubing to stop it melting on the exhaust.







The batteries arrived today, the box looked pretty ordinary but weighs 30kg !! They come in pairs and were both made on Guy Fawkes night last year so I hope they don't blow up LOL.. I've decided to tuck them in behind the drivers seat against some close cell foam to keep them secure and at cabin temperature, not sure how I'm going to strap them in yet.

Another update as the layout is now getting fixed. Stuff has to arranged so things are removable as required so when using wood-glue I've been a little cautious where it goes.



Wood (Cedar IIRC) fixed to the floor (33x33mm square) uses 2" no.8 screws and bite to the 10mm hardwood ply (2mm pilot holes) very nicely. Uprights are glued and screwed (2.5" no. 8 screws into 3.5mm pilot holes) to the lower rails before fitting. Fixings to the van are via no.8 woodscrews into the 2 or 2.5mm pilot holes, but really only needed for steadying / locating as the floor should take the weight, spread out on the framing.

Plastic containers are 45L Wilko boxes at £7 each and at 28cm tall can lift up slot out into the passageway for access. This gives 135 litres of out-of-sight storage. The framing also offers possible secret voids from boxing in with ply to hide a tracker, laptop or something if the van is burgled. The rear bed is 85cm wide from the 4mm side panels which will be brought out to 10cm (bed becomes 75cm wide) to fit flush down that side of the van covering the electrics with a long thin cupboard.

There's an 'upstairs' and 'downstairs'  set by the framing. The top of the framing is exactly 36cm above the floor to give a nice amount of headroom and just enough space for the Wilko boxes to slide out (360 - (2 x 33) = 294mm is just enough!). The Fridge will live upstairs.

There will be a spare bit of house carpet added which will cover the floor and toilet cubby to allow that to slide out (will have to add restraint/door for driving!), the 192cm long bed area (slats) will end near the upright to the RHS of the toilet and a thick curtain drape will be attached behind the moonroof for privacy is travelling in 2s. Need to take the headlining off to bolt a curtain rail in.
Note also the extractor fan pipe and the heater pipe - heater is in red in the background, their routing will change.

Run out of framing wood now so I'll be doing plywood bits until more of that arrives, ply will add strength to the framing. Flexible 8mm beech bed slats will be used for the rear (top) part of the bed toward the back door, the rest probably as fixed 16mm slats as fixed is easier and flexible ones won't improve comfort of legs I don't imagine. Slats will slot in place for access.

Also if solid board is used the mattress can't breath and everything rots, so slats are a win-win!

Congrats on your 1000th post!

Your setup is really coming along nicely, can't wait to see how it all comes together.

That's really looking good, but don't think your layout is settled yet, at least if there is a female involved; you'll be figuring out what you can move to fit in her latest request .........and the next .....

BTW good choice of the Weller soldering station; they're so much better than the famous Hakko ones that everyone seems to like.

LOL, yes, very true.

Had the Weller a while, in it's 2nd element now. It can solder 16mm wires to tube connectors given time on a #8 tip so quite versatile!

Currently working out my grounding plan as the current sensors I bought want to be on the -ve side of the batteries which is a bit of a pain but with careful planning I think it can be done. The battery earth strap is out of course as starter currents use that so it's all down to an analysis of the ground currents rather than the voltages for that!

Still waiting for a few bits, moved the B2B charging stuff into a separate board now as it helps the layout, will take photos at some point!

ETA: Earthing scheme for correct current meter readings:

Looking almost identical but with much more work done:



Still awaiting some parts but it's coming along. Because it's a prototype / custom build it's a bit slower than building from plans, but the layout is more fixed now. The electric + heater section is well sorted out now with just a few details to check.

Gone over to 6mm ply for the shelves which works well.
Heater pipe goes into a unequal Y branch to cover front and back. Had to trim the outlet as the shelf is a bit narrow!

Extractor pipe can be seen entering the fan box, (a 100mm electrical box was the right size) as the 80mm fan fits inside. The big pipe with the two holes is for conduiting wires from the switch panel to various stuff like solar, 12V outlet, fan, heater.

The RHS cupboard side is nearly done and slots in, running a bit low on wood but hoping I don't need to add much now! All seating+bed surfaces will be flexible bed slats in pockets as they are nice and thin and the flex is more gentle on the structure.

So from front to back it's the batteries in a narrowish slot, then the toilet space, then the electrical zone + heater, then the main fixed bed/seat area to the back. haven't started the LHS cabinet yet but hoping it gets a bit easier as the ways to do stuff get worked out.

Got my battery saver today so the DIY multi-voltage bi-directional B2B is complete!



Basically a 3 wire unit with 24V, ground and 12V.
Although it looks massively complex it's not really and this is what it does.
It's designed so the 24V side goes via a switch for long term storage.  

At the heart are two power converters, one to charge the 24V pack from the 12V side, and one to charge the 12V battery from the 24V pack. Both chargers are set to float charge at 13.8V and 13.8 x 2 = 17.6V.
This will NOT give a full charge especially if you have an AGM leisure battery so a proper AGM capable solar and EHU based one is needed for that. Having said that whapping up the voltage to 14.7 x 2 = 29.4V is the turn of a screw...

The relay wires are colour coded:
Black, coil earth
Red,   coil switch
Purple, common
White,  normally closed
Yellow, normally open

Therefore:
Whites  = charge the 12V battery
Yellows = charge the 24V pack.

Both 24V and 12V inputs to the board are fused (orange 5A for 24V, red 10A for 12V)
The split charge detector drives relay #1 (LHS) which switches the 12V.
Relay #2 is driven from Relay #1 and they always switch effectively together.

At rest the white relay leads are connected to the purple relay leads. This float charges the 12V starter battery via the top LHS power converter, but via the 24V battery saver (bottom RHS). See the white wires, active when idle.

When driving the white wires are disconnected and the purple wires instead now connect to the yellow wires from the relays.
The yellow wires then connect in the top RHS step-up power converter that then float charges the 24V pack, until the split charge sensor decides it shouldn't.

Simples. I'm sure Victron should have already made one of these with a lower power 'don't-charge-anything' mode....

More van progress:





I found Reimo 19L tanks are the right size so 2 just fit in there, one for feed one for waste. I have a small submersible pump so when I find some pipe I'll make a tap from some pipe so a momentary switch and a one-way flow valve should do the job. Then I'll need a sink+drain for tank #2 and access from standing next to the sliding van door to pick them up for emptying and filling.

The big LHS cupboard is coming on, will just have top-lids for these as there's no space for doors anyway with the bed height.

Still waiting for my battery isolator switches so no electrics yet, although I did relocate the green MPPT solar controller so I could see the display!

19 litres seems a little small unless it is a one-person setup; our requirements in NZ are 4 litres per person for three days so two people -> 24 litres minimum for both fresh and grey water tanks, NOT including the toilet which must have 1 litre of clean water per person per day for three days. We have a 25 litre fresh water tank which is a jerry-can like yours and a 27 litre grey water tank which is rectangular, from the standard range made by a company not far away, and the toilet has its own tank within itself.

We also used a small submersible pump which I made up a variable speed control for, however we don't have the one-way valve so it is best to turn the pump on full until the water comes out and then turn it down to what flow is wanted.

Your regulations in NZ seam very pedantic verging on draconian or are they just advisory, we have toured Oz and many times where told oh just dig a hole and bury it especially the chem toilet as its taboo to contaminate there cess pit . Hear in UK we free camp often take everything with us home or to the next camp site grey water its acceptable to water a tree (and also in Europe) we have no regs at all on size of tanks or even having any. Its just common sense for all free campers to leave no trace but there are always idiots who just dont care whether campers or not.

19L is actually quite big for the size of van, 10L and 12L kits are commonly sold for small van conversions here!

E.g:
https://www.ebay.co.uk/itm/COLD-WATER-PLUMBING-KIT-TAP-PUMP-2-X-10L-CANS-FOR-CAMPERVAN-MOTORHOME/142974276565

I did look at 25L round tanks as they are very common and cheap but I'd need to step out the side of the unit quite a lot for that. Lots of space to add 6L of bottled water anyway

My key water-saving feature is a momentary switch so when you stop pressing it the pump shuts off.
Good idea about variable speed, I have a spare PWM control I can use for that - definitely will use that.

@JT69 that is the requirement to obtain 'self-containment' certification here. It is absolutely discouraged to 'water a tree' or leave any other discharge. Many towns provide dump stations where grey and black water tanks may be emptied into the town's sewerage system and there is always a clean water tap there as well to fill your fresh water tank. I don't consider the regulations to be 'draconian' at all, just good sense, and they're not that hard to comply with. Also it isn't necessary to have the certification; if you don't it simply limits where you can camp without receiving an infringement notice and fine. Clearly if you always use proper camp grounds or park at people's houses where there are external facilities there is no need for self-containment.

@GPW on my PWM controller I used a pot with switch as per a radio on/off/volume control so fully anticlockwise is OFF and clockwise rotation turns it on at the slowest then advances it with further rotation. The pot is fitted just behind the faucet for easy access. Works well, but a non-return valve would be an improvement although it doesn't take long for it to pump up from the tank each time.

My housemate is now having second thoughts about the van though and we may end up quitting it as it is just too low to the ground. It only needs the wheels to go down a small dip like the rain channel crossing at a driveway or after a speedbump and the fibreglass moulding hits the ground and is damaged. Continually having to have the bodywork repaired is becoming too much of an issue. The previous owner says he already had it raised a little so it must have been impossible before; we will make inquiries as to whether it can be raised some more but I think it really would need to be a lot and may not be possible or economic. it's really disheartening as I put in so much work on it and it now seems likely to have been for nothing and I don't want to throw any more time or money at it if it really won't ever be properly usable.

AgathaAlice so as I understand a self -containment certificate is mandatory in NZ but only if you want to free camp and to avoid a fine (good legislation we have seen far too much fooling with human waste throughout Europe) as for grey water there is no problem with grey water in Europe it is no problem think of all the animal waste that is biodegradable as is grey water.

Yes if you have self-containment then you can freedom camp except for some places which have local by-laws in force to prevent it, otherwise you're restricted to official camping grounds (which cost for their use, of course, although it is often very reasonable) or parking up at an acquaintance's place using their facilities or similar. If caught freedom camping without self-containment certification displayed on your camper you're likely to be awakened at first light by a ranger who will issue an infringement fine: they do random patrols of areas which have become known as popular spots. To me it seems quite sensible.

By the way if you missed it in an earlier post, my name is Tony and my housemate who is the user of the van is Carole. The name Agatha Alice is of personal significance to Carole and she chose to name the van for that, so that is what I used as my log-in.

Slightly more progress now my main master switches turned up, so now I can isolate the 24V and 12V at the flick of a switch. So there are 40A and 50A 'disaster' breakers at the batteries themselves, then into the 100A/300A isolation switches.

The 12V then goes to my B2B board, 5 switches with their own mini-breakers and the 12V power meter, the 24V goes to the 3 remaining mini-breaker switches and the Victron.

So my 24V to 13.5V regulator on my B2B board had a spaz and killed itself so I put in a different, lower power (15A) one which is also a known RF quiet one so that's current working well. When I put the van lamps on in the back it now registers the power from the 24V pack as the power is coming via that regulator and the van battery is not really involved at these lower power levels.

I'll have to see when it does when I start the van with it connected as it will then be pushing full current while cranking - no current limit on the regulator so it will hopefully max out at 15A and I'll have to fuse at 10A in, 20A out.

I also tried my A++ mains Table-top fridge on the Victron, initially the Victron's fan comes on but it soon goes off, the running power the fridge uses from the 24V pack is 36W. I checked and the mains voltage was fine, the almost silent compressor was running and the freezer plate was getting cold: 36W runtime, amazing.

Woodwork is coming along, sink/kitchen is almost done, my optional solar is wired, 12V outlets and USB are wired and working, hoping it's not too long before it's in action and I can attempt to reclassify it as a campervan.

36 W is really good, must be a good efficient fridge, and that would be allowing for the inverter's own power requirement also so the fridge itself will be a little bit less still.

You could always connect a relay which has a normally-closed contact between the vehicle battery bank and your system, with the (24v) coil connected to the 'start' contact of the key switch, this would isolate the starter motor load from all your other gear and restore connection immediately after cranking ended.

Yes I was quite surprised at 36W, that's camping fridge levels of power. It was the only A++ Table-top I could find, the rest were A+ rated only. It has no radiator on the back, heat dissipation is just from the black compressor enclosure so it's very neat.

The Victron is a low frequency inverter so probably very efficient at low powers (standby is 5W (2W on 'search mode' when it only switches on for a second or two every few seconds), most inverters eat 1 amp just sitting there so for them it would probably use 45W odd and 12W when not running.

Good idea about the ignition, but I've decided to go for a MKIII B2B setup now. Basically this will completely separate the 24 -> 12V step-down part to a simple circuit on one of the switches with breaker. This is because the use case is only when I'm actually in the van. I.e. when I stop for fuel or park at the supermarket I don't want the 'non-charge -from-alternator' mode to do anything at all !

So my B2B board will become a simple auto-sense-relay+stepup so I also have a chance to add a parallel or different step-up (i..e more space) to get my required 15A 24V charging current (around 440W max into 28.8V).

Here's my sink with the MK1 tap!



There's a speed control for the water pump, the tap is just 10mm copper into a speed-fit elbow that then goes to the regular outlet in tank where the pump is connected. Filling the tank is waiting for a tank-fitting to turn up.

The waste tank has a cunning silencer / water-trap - simply the hose extends to the bottom of the tank, and just unhooks from the sink when I need to take out the tank. Not sure about the magnetic clips, I'll have to see how they work for the panel. I may re-make the tap as my pipe bender was a bit severe, I think a nice wide curve would be better.

The sink is an 8L stainless mixing bowl, I bought a carbide drill and using oil I drilled it. The drain is from the rather too-small sink I bought before, unfortunately I couldn't find a small drain separately. The drain is sealed to the bowl with acrylic filler and clamps the bowl to the micro worktop.

Above the sink on the pillar in the background is the heater control.

Hey I f***ed up on that relay anyway as I have been thinking lately about vehicles with 24 volt engine and 12 volt house systems. As yours is the opposite the relay coil would have to be 12 volt of course, but anyway you've solved it another way.

That setup looks good but you can get actual small sinks (as we did) with the standard waste connection. Where your bowl may win though is draining when the vehicle isn't level since that shape has to drain regardless; ours does have an issue on some angles. Don't you need to have a P or S-trap to prevent any smells from the grey water tank rising up back into the vehicle?

We're not having any luck finding a vehicle to suit Carole; everything that comes up is old, has eye-watering numbers of kilometres on the odometer and has rust showing, which means even more that's not showing.
The new radiator gets installed in the Hiace tomorrow; the mechanic thinks he has been able to fix the courier damage so by this time tomorrow it should be leak-free again unless Murphy's law intervenes yet again.

Talking of 24V vs 12V, one annoying undocumented feature of the Victron is that the 1A feed for the 'starter battery' is the same voltage as the domestic battery, i.e. they expect you to have a 24V or 36V starter battery for the 24V and 36V models! I may fit a 3A buck regulator as I have some nice quiet ones, but it would be simply to miss it out altogether as I already have my 24V to 12V float plan.

I also just fitted the 10mm wooden frame right under where the bed slats go to tuck my portable 80W panel, it just hands under the slats - much more space there than for a 80W in fact.

The cunning point about the long pipe is that it stops the smells just like a water trap, because the water in the pipe will only be of the pipe area, just like in a trap. I.e. it's like a dynamic trap with pipe extension... all the smell from the surface of the waste water just stays in the tank as it cannot get into the pipe.

It may be easier in the long run to go for a good vehicle to convert rather than a ready-made camper, due to the better condition of the base vehicle. I'd choose a Peugeot Boxer if I was doing it, VWs are expensive and rust IMO. Another option would be a petrol, manual Hiace. One thing I found eats up the time of converting a van is the problem solving and rework, if one can solve these issues somehow it becomes a more realistic proposition.

There's also the economical Fiat Doblo hi-top route, it makes a tiny occasional camper but they are so cheap and frugal it's an interesting alternative.

The Hiace is just a bit too small, she definitely wants something around the size of the Toyota Coaster or the Nissan Civilian (although unlike Toyota the Nissan people here are NOT good to deal with; been there!). She'll just have to be patient and keep eyes peeled for a bargain and maybe go for a year or so with nothing while she looks and also sells the existing one. She can have fun looking at everyone else's and picking up ideas for layout in the meantime.

Anyway Murphy did indeed strike again, the mechanic removed the radiator from our van and found it is different from the one we were supplied; seems the apprentice at the wrecker got the year wrong so they're now sending another one direct to our mechanic (hopefully more adequately protected against couriers), meanwhile as 'insurance' he has dropped our old one at a repairer's to see if it can be readily repaired. The story will continue in a couple of days.

Yes the Hiace's size is challenging!! The Super Custom even more so as the sunroofs use a bit of space, I'm having to set my 'look out the side door' seats a little lower than the bed so I have headroom there. The high floor is the main issue - the Renault Trafic has a few extra inches on it due to the low floor in that.

I think there is also the 'use case' decision too, because it's compact the Hiace is good for parking and quite fun for short holidays, for longer more serious trips one really needs full standing headroom and a working shower with hot water, so that counts out ALL the little mini-vans (including the VWs) and puts you into Sprinter / Ducato territory.

Once there the Sprinter is expensive, rusty and narrow so you are left with the Ducato as the only viable panel van. The Toyota Coaster looks nice and spacious but quite a bit bigger than a Ducato - but will it be too big?

Shame about the radiator, it's the same all over, attention to detail is not really a 'thing' these days... still you may end up with a better one at the end.