Camping conversions!

My never ending conversion is progressing too

I discovered from the growing pile of dead DC-DC converters that the current sense for them was on the ground side of the converter, so I can't use them as common ground converters like the old 7812 at all.

This wasn't an issue for the regulators I used for the lights etc as the current of the load is limited, but battery charging has no limits so the current regulation of the converter is required to work.

So I've now completely isolated the ground of the 24V system from the van. This involved removing my link that connected them together in the first place.. Technically I could connect them with diodes but I'm not seeing any need yet.

They appear to like this arrangement much better...

Ok so some progress, I managed to get the MPT7210A solar converter working and it nicely charges the batteries for free in the van, so that's working well.
I can recommend portable solar, it's quiet, simple and just charges everything up like a dream, great stuff.

Less good news on the bed, I ordered the mattress foam in 4 parts:

145cm x 75cm
44cm x 75cm

145cm x 44cm
44cm x 44cm

from an eBay store they sent me 4 mismatched pieces that don't fit together and the large bit is even cut out of a piece of foam 1" thicker than the rest.
I'm failing to understand how they managed to get such a simple order so wrong, cutting errors are up to 3cm in places and the thicker bit is difficult to miss. Now I've got a lot more work in working out how to wrap it all back up to return it.

I think I'll go for a different company, big single sheet and trim and cut it myself as even a blindfolded Orangotan could do a better job and at least it would all be the same level.

I'm understanding more now why people buy campers ready made...

LOL. Wish you were here, we have a tame upholsterer who would get you what you wanted with no difficulty and would cut it for you accurately exactly to your requirements right in front of you while you wait.

Carole has placed advertisements on various media to sell our beast, but as she's been told, just coming into Winter isn't such a good time to try to sell a camper.

Ha yes, I desperately need to find an upholsterer here!!

The advantage of putting a van up for sale for the winter is lack of competition and it gives the new owner time to tinker until the spring.

Ok so a little more info about the 12V van and 24V house system I used.

The mixing of voltages has a number of pros and cons:
Cons:
1. No simple split charge system

Pros
1. Many van items are irretrievably on the 12V van battery like interior lights, radio etc., this system causes the van battery to 'disappear' electrically from the system while remaining connected (see float charger below).
2. The Victron Multiplus inverter/charger can use thinner wires (i.e. connections are less critical)
3. Single down conversion from 24 to 12V (more efficient than a dual conversion battery-2-battery (B2B) charger
4. Single up converter from 12V to 24V

In practice once you move from a direct split charge relay to a B2B (which are usually needed for lithium anyway) then the voltage of the domestic bit doesn't make much difference to the circuit or the issues. A Victron (etc.) B2B costs hundreds of £s, my DIY system probably comes in around £55 in parts.

I use the word 'converter', 'charger', 'regulator' referring to a step-up or step-down DC-DC converter.

12V to 24V charging - the charge-while-driving bit:
The main problem I've had was with the commercial auto-voltage sensor that detects the engine is running. It had some hysteresis but cut in at 13.2V. Then if there was a heavy load then the input voltage would drop below that and it would switch off again and form a low frequency on-off oscillator. So I had to take it to bits to adjust the voltage to 13.4V (to allow the van battery first dibs!) and add a small capacitor between the 'on' relay drive and the voltage sensor bit inside, so that when it switched on or off it got an extra kick in that direction, which slows down any opposing decisions.
This sensor drives a relay for +12V (the unchosen switched 12V relay pin then goes to the input of the float charger below) and the Gnd12V relay is driven from the first (so the sensor only drives one relay coil).

Thankfully there is an amazingly good step-up converter on eBay for this job, e.g:
DC-DC-1200W-20A-Adjustable-Boost-Step-Up-Converter-Power-Module-8-60V-TO-12-SG
which has 3 controls, 1. output voltage, 2. current limit and 3. input battery voltage protection. So the output voltage is set to 29.4V for my AGM, 28.8 for Gel/Wet/Carbon, the current limit to the limit of the batteries (my small AGMs are limited to 10A charge) and the input battery limit which I set to 13.6V. This battery limit is ace.
A little 40mm 12V fan cools this converter when activated from the input via a 50 ohm resistor.
The charge voltage is set to 29.4/28.8 for peak charge as it is rare driving will be to too long and the Victron will do the full 4-stage voltages when on EHU. One shouldn't leave it on this voltage for days.

The 24V to 12V float - the clever, van integrating bit:
The float (13.2V) charger is a simple aluminium cased 15A DC-DC stepdown converter (with added 30mm fan switched by a 40C temperature sensor on the heatsink) and is powered via an extra 'battery saver' module to protect the 24V battery pack from over-discharge.
This charger doesn't do the full 4-stage charging works on the van battery, but will simply maintain the storage/float charge and will top up when required. 13.2V is chosen as it's the storage charge of a lead-acid. This means it always has enough juice to start the van and run all the stuff, but doesn't waste any power and doesn't corrode the battery so it can be left on for long periods of time.
When enabled the van battery itself rarely gets used for anything - e.g: switching on the radio or interior lights draws current from the 12V line but the float charger keeps the rail up at 13.2V. This means that (within the float charger's current limit) any power used from the 12V system gets drawn straight out of the 24V house battery via the charger. You can see this on the current meters, switch on any 12V item and the current is drawn from the 24V pack. It's like magic, and something only this mixed voltage system can do. Then when (for instance) the diesel heater needs 20A the charger maxes out at 15A and the 12V van battery supplies the rest, which is replaced over time after the heater switches off the glow-plug. It means the van battery will only start to be depleted after the house battery is dead.

Summary:
Electrically it's a bit subtle as you have to be very careful with the earth currents flowing in the regulators/chargers. The regulators use resistors (a wire loop) on the output -ve/earth to sense/limit current. If you ignore or bypass them the regulators go 'phut' very quickly. Only use these as 3 terminal regulators for known devices like LED lamps as leaving the output -ve disconnected disables the current protection of the switching FETs, which you really need to protect for battery charging!!
The 12V battery and electrics are generally earthed to the van by Toyota. The 24V earth then only really goes to the Victron and solar as well as the regulators. The Victron's earth (and EHU earth) cannot then be connected to the van chassis unless via diodes! The two DC earths are also of course connected together via the regulators own current sense resistors so you can never have the two regulators on or connected at the same time, diodes are used in the -ve outputs where required to prevent this.
My 12-to-24V charger has an internal output diode so is always connected to the 24V (via a fuse!), but the input is via two relays on the +ve and -ve 12V inputs, driven by the voltage split charge sensor.
My 24-to-12V float charger has none of that so has a schottky diode on both the +ve and -ve outputs.
The idea is than when operational each charger's own -ve in to -ve out is the sole connection between the power source and power sink (load). This keeps it happy and working.

@GPW, it's been a few months, how's your conversion coming along

Hi,

Well it's been finished for a while, on the basics.
I need to have some cushions made up, that's the only real work to do.

I had to play around with the switched charge sensor and to add cooling fans to the 24V-12V regulators, using a 40C bimetallic switch for the 24->12V one as this is the float charge, on for long periods.

Curtains are needed, but the structure and layout is all in and finished, so just textiles left.

Great that you're at such an advanced stage with your project.
I'm grappling with the battery charging setup in our new vehicle and unfortunately can't see any really good solutions short of spending huge amounts of money so I'm stuck with the equipment that was in it when purchased. Redarc have a unit which (at great cost) does most but not all of what I really want. I feel like emailing them and suggesting what else is needed so they could do a 'mark II' version, no other manufacturer looks to come near.

What is the issue with yours?

For mine, the main issue was the voltage sensor, which had very little hysteresis, and so cycled on and off far too often.
I managed to take it apart, alter the 'On' voltage and use an additional capacitor to give it a good kick when it switched, so it didn't think about anything else for a while.

Victron have various good solutions too, but also expensive.
Perhaps a DIY solution with an Arduino and some very simple software to manage some delay and hysteresis, may be the answer.

Money!
We have three sources of charge which are independent of each other and the vehicle battery is a standard lead-acid while the house battery is a lithium pack of four cells with no protection or balancing system. There's a VSD which links the two together when either is sitting at an adequate voltage to charge both.
The solar regulator does a great job on its own, along with the VSD when the vehicle is not in use.
There's a mains charger in parallel with the solar regulator output which can be used if there's mains and no sun although its fan is very noisy (must see if I can fit a quieter one, you wouldn't want that going while trying to sleep).
When the vehicle engine is running the alternator is directly feeding both batteries and seems to put out nearly 15 volts, I need to check that as the lithium won't be liking that very much.

Those three are basically working against each other and that makes all the multi stage charging irrelevant.
If traveling and the sun is shining well there needs to be a way of disconnecting the alternator from the house battery (why pay for diesel to do what the sun can do for free?).
There needs to be some control of the charging of the lithium when the alternator is operating rather than just brute force.
The mains charger should operate only if there's insufficient sun. Presently manually switched.
The house battery needs to be disconnected before the glow plugs come on to prevent the solar controller turning off the load when it thinks the voltage has gone too low before the VSR's start protection has come into operation (currently I have glow plug and start relay feeds via diodes to the VSR protection input but it is not fast enough to stop an occasional shutdown of the solar at 11.1 volts).
Everything should happen without manual intervention by a non-technical woman.

The Redarc Manager 30 unit does all the necessary things except keeping the vehicle battery topped up during long periods of non-use (winter etc) and balancing of the lithium cells but is very much outside our price range. It also has facilities we'd never use like Bluetooth connectivity for example. I'm unsure about its level of RF interference radiation, our present solar regulator has a nasty fur all over the spectrum analyser screen on the FM broadcast band and so far attempts to filter it have been unsuccessful.

Sorry I haven't replied to this.
I read it a few times, but didn't come up with any solutions, so I didn't know what to write!

If you can draw a diagram of where the current flows, and where the devices are (a schematic of the whole system) this would I think be easier to analyse, and might suggest some obvious improvments just on inspection.

It sounds almost as complex as my multi-voltage system

It's not complex at all, it's really very simple, but can't do the things the way I'd like and the three sources of charging are not able to communicate with each other to know what is actually happening. For example if the solar has just done a nice dual stage charge and the vehicle is then started the alternator immediately bumps full voltage over the battery via the VSR regardless of the fact it is already charged. Similarly with the mains charger. There's no answer using the equipment that is there and there is no money for anything nice like that Redarc unit, obviously manual switching would overcome all the limitations, but a non-technical woman can't be expected to know how to use such switching.
The other issue that probably needs more immediate attention is that there have been a lot of motorhomes stolen recently over here so there is a need of fitting an alarm system / 'immobiliser' to at least make it more difficult for someone to steal it. We had a nice Uniden alarm in the orange monster and it worked very well despite the bad reviews Uniden have, I've been trying to find an identical unit but nothing has come up at anything but exorbitant pricing. There is also an issue with the 'house' door in that I can see no way of fitting an actuator for locking / unlocking and also of fitting a switch to give 'door open' status and another for 'locked / unlocked' status so the alarm will work correctly with it. Without that it will seriously diminish the effectiveness of the alarm unit.

Anyone on here got a Uniden VS2600XR or VS1600XR alarm unit they don't want, with at least two remotes? I have a full install kit just not the unit itself and any remotes, also like a fool I let the installation / programming manual go with the orange van and have been unable to find a copy on the internet; plenty of user manuals and I have an electronic copy of that but it doesn't go into option programming.

I see, so the main issue is three sources of power, into the correct 4 stage charging profile.
But the only cost of a wrong profile, is reduced battery life: cheaper to buy a new battery now and again, Lithiums don't care about a profile anyway.
To prevent manual switching, some decent Schottky diodes (I use this in my van, 20A T220, parallel as needed), or a more expensive 'MOSFET' smart diode.

I don't understand about the 'house' door - the sliding door?
A useful alarm is a basic cheap one that works off the door lamps (the rear section is a different circuit, so needs two diodes for the '0V = open' signal. Then put the siren inside the van: if they open a door when it's armed, they get deafened.

OK it's very hard to explain the charging problems, diodes won't do anything the present setup won't do. What it needs is some intelligence to choose the best charging source(s) available at any time and provide the result to whichever battery needs it without any human intervention.

Regarding the alarm, as we don't now have a Hiace we don't have a sliding door (or even the batwing thing the orange monster had). What we have is an outward opening door which is supported on a couple of hinges and has a lock with a large lever for use from inside and a key operated turn latch on the outside. The lever has a very large travel and is entirely visible so while some very large solenoid could be made to operate it the result would look awful and make hand operation difficult. Think the old 'trafficators' that cars once had! Similarly fitting reed or pin switches to give the status would be visually unacceptable and physically difficult and even getting wiring for all that back to where the alarm unit could be mounted is not a trivial exercise so at least at first the alarm would only be able to operate the front doors and disable the starter and the fuel shutoff valve which would be better than nothing. At least it would mean that to steal the whole vehicle without using a flat deck truck or trailer or wreck the autobox by towing it, a thief would have to take some time to find and disable the alarm unit which I could hide fairly well.
Yes two sirens would be the go, one that can be heard outside by nearby people and the other inside like the one I have on my house alarm in the ceiling just above the keypad, that thing is so loud that even with earmuffs it would be unpleasant.

The diodes would guarantee that the largest voltage had priority. If that voltage had insufficient current then the voltage would get pulled down, and another power source would then also contribute.
For a very low battery, all sources could contribute for a while.

So the intelligence of the diodes is simply to manage any higher voltages into the battery terminal. This would work reasonably well, I am trying to think of disadvantages: apart from the small voltage drop over a diode.

What do you see as an issue with this system: what have I missed?
I would be interested in a photo of the house door! Is this an original Toyota feature?

What we have is a Toyota Dyna which is a light truck, it (along with many others) was imported into NZ as a truck chassis and fitted with a camper body by a company which was based in Auckland so the 'house' bit is of their making, however it has seen extensive modifications and rather a few owners since the guy whose company it was sold it so there's nothing Toyota about the camper part of it. We are in contact with him and he has helped with various things despite that it was a lot of years ago he built the thing.

The power system which is not what the guy fitted originally consists of a pair of 160 watt solar panels, an MPPT regulator, a bi-directional VSR connected to the vehicle battery, and a mains charger which is controlled by simply switching on or off the power point when shore power is connected.
When the vehicle is parked up and the sun is shining the solar charges both batteries via the VSR, that's fine.
If the engine is started the alternator gives greater voltage than the solar is set for, the VSR connects the alternator to both batteries and so brute-force charges both, even if there's plenty of sun so we're spending diesel to charge the house battery when the sun could be doing it for free.
Again on shore power the charger is connected by the VSR to both batteries if it is turned on.
It all works, but it is obviously far from optimum, especially the lack of control with the alternator going and I can't see any use for diodes in the setup.
The lithium battery is four separate 100Ah cells in series with no protection or cell balancing and probably doesn't like the alternator very much. If / when it dies we'll fit something different provided it doesn't destroy the whole vehicle explosively!

Anyway don't worry about it, if Carole's health doesn't improve we'll likely dispose of it as I doubt she'll ever really use it.

All noted!

What is the max cell votage of the lithium cell?
A 'Lipo' is 4.2V, 4.2 x 4 = 16.8V, so it will be safe, but never charged.

The problem with direct charging of a lithium from an alternator is not the battery's...
.. for a 100Ah cell 100A is only 1C, not such a big deal.
The problem is one of alternator cooling: on idle the alternator is working very hard, but the fan is spinning slowly. This can and has melted the windings on alternators, and is a major reason for a battery manager for lithium: a current limit.

So when you charge the lithium from the alternator try to keep the revs up!

I'll have to look at the voltage next time I'm outside, it's written on the cells, but I think it's around 3.7 volts per cell. It handles my load tester wound up to its maximum of 20 amps without any sign of drop so it's certainly getting nicely charged by the solar.
It would be rare for the engine to be running but the vehicle not being driven so cooling shouldn't be a problem.

BTW I know I shouldn't really still be here as we don't actually have a Hiace any more even though the Dyna is incorrectly recorded on its registration as a Hiace, however I've made no secret of it and the admin hasn't booted me out yet! When they do I'll accept it and go quietly, meantime there are some similarities between the two kinds of Toyota which make it seem worthwhile to stay.

I was a bit remiss in updating this, here's a shot of the inside from the front, showing the bed, slats, sink, cooker (needs a metal shield behind)

The fridge slides forwards it's own length when the front seat is slid forwards, and a hinging wooden leg supports it just behind the seat.

This then gives a reasonable seat area there.
I still need to add deyails such as a folding table, but in essense it's done.

Above the fridge, between the two LHS windows you can see the heater contol.

can someone tell me the measure
1. across floor...wheel arch to wheel arch
2. above wheel arch....side panel to side panel
3. rear door...opened width

geoffreyKZH138V wrote:

can someone tell me the measure
1. across floor...wheel arch to wheel arch
2. above wheel arch....side panel to side panel
3. rear door...opened width

Hi,

Measurements are fairly accurate, but not guaranteed!

The metal to metal stripped out width inside is about 60"
The wheel arch width with carpet still in place is about 42"
The opening is about 53"

I designed my camper bed to expand to 47", so a narrow cupboard on one side, and the other build out to cover the wheelarch (to give a corridor to the back - see my custom/campervan photos.

Hello Folks

‘Found’ this theme from the post here: https://hiace-super-custom.forumotion.com/t4300-sound-proofing-old-work-hiace-van#23986

Towards the bottom of that post I’ve added a few pictures of the rear area of my van, currently. You can see it’s practically empty as I’m going to be adding some sound and thermal insulation plus will be improving some of the electrical systems. My van is a LH119 ‘Cruising Cabin’ and all the camping and seating is out and safe and being tidied up ahead of re-installation. All lots of work but worthwhile.

In general the improvements will be:
1 – sort out a bit of rust and improve the sound and thermal insulation and improve / install the wiring for:

2 – install a 240V hook up. Quite a few of the CCs seemingly had this, based on the manual but not mine. It was not very sophisticated and just linked a hook up cable (actually probably 110V) to a couple of sockets on the cabinetry. My van has the RH side external cubby, which on some held batteries and on mine holds the grey water tank. There’s quite a bit of spare room in the cubby, certainty enough for a 16A-style. At it’s most simple it’ll be something like this:
https://www.screwfix.com/p/abb-16a-2p-e-surface-socket-250v/1858f But its exact shape will depend on where I put other bits.

3 – install a diesel heater. I’ve already got one of these. It’s a 2kW Autoterm unit and it’s been lifting the temperature (a bit) in my garage all winter and has made working on the van there a bit more convenient. It’s too small for the garage but will be fine for the van. I did a lot of searching about before going with this and think it’s great and am looking forward to getting it in the van. Not quite sure whether it’ll be fitted ahead or behind the rear wheel arch but it’ll likely be fed from the fuel tank (via a filter with a tap I got at the same time) rather than a separate fuel tank. I do have one of these, but think that when the 2kW heater goes into the van I might get a 4kW unit for the garage. Will see. There are a few posts on this forum about diesel heaters. Contact me if you’d like to know why I got what I did.

4 – improve the electrical system with an inverter (prob just small ~1.5kW max). Improve the leisure battery arrangement. The van already had power fed from the alternator (see my post on ‘what is this 40A fuse for’) but it needs a proper charging system for a leisure battery, a half decent battery storage capability and possibly solar. On the 40A fuse thing, I think I'll replace this with a much larger ~200A and put a 40A fuse or trip somewhere accessible. Having to lift the driver's seat to fix this is a rear pain and a poor location for this. I’m doing lots of searching and talking to folk on these and everything here is both expensive and has a lot of compromises. I might go for a more portable system that can be used elsewhere rather than design, build and have to lug about a permanent system that can’t be used elsewhere. Hopefully it’ll be Lithium, but will see.

These are the main areas. The van is already a camper and want to keep this original fittings as much as possible. They just need a bit of a tidy up, clean etc and a few small modifications. An example of these will be improve the storage within the van as the long cabinet needs adapting to be more functional. Another is to sort out access to the rear seat base so that the useful space there is more accessible, which is not the case now. More stuff as it happens…

Cheers!

Beware your local electrical regulations! Here in NZ we have what is called the 'homeowner exemption' which allows us to do (quite) limited mains wiring in our own house but DOES NOT extend to recreational vehicles, all of that must be done by a registered electrician! An electrical warrant-of-fitness must then be issued for the installation by an electrical inspector. This may not apply in your country of course.

Remember that LiFePO4 batteries require a quite different charging profile from the old lead-acid batteries if you're not to shorten their working life, and at the price of those things that is something you surely don't want to do!

No I don't have any solutions yet either.

My view is that Lithium is not currently worth the trouble.

You need a B2B device to charge them safely (Although my 24V system has intrinsically got that, as my 12-> 24V steup has a current limit (when wired correctly, the current sense is on the ground side!), and the Lead-Carbon batteries seem to have promise, for less money.

Also a battery is only a store of energy, not a generator. For long periods off grid it's more important to get the solar sorted out, so on average a days input is >= a days usage.

Also buying lower power items too, low power lights, laptops etc. The only real drain on mine is the heater, or inverter if loaded.

LH119V wrote:

4 – improve the electrical system with an inverter (prob just small ~1.5kW max). Improve the leisure battery arrangement.
Cheers!

My advice: Buy a Victron 'Multi'. It's an inverter charger.
They 'seem' expensive, until you understand that:

1. They are bullet proof and have a big surge rating
2. They do auto-switchover for EHU mains hookup, inc grounding.
- No stupid switchover wiring.
3. They include high power chargers.
4. The sine wave is perfect: everything will work
5. They will idle at 2W parasitic drain. Nothing else will.