How to stay longer off grid (compressor fridge).

[Minxy]

All the previous post`s regarding Compressor Fridges...

I asked a similar question when we got our PVC....

And most of the above have just confirmed...

Who would be willing to put an ordinary 12v/240v/Gas fridge in for me, down South..????

Any idea`s..???????????

I know it means cutting a hole in the side for the vent and exhaust, Gas supply is near by.. but would sooner have that than go away wondering when the battery`s were going to let me down..

Mo, why not just get your solar/battery capacity increased, for the cost of changing your fridge (if it could be done) you could probably get a good lithium/solar set up.

 

[CazPaul]

Mo, why not just get your solar/battery capacity increased, for the cost of changing your fridge (if it could be done) you could probably get a good lithium/solar set up.

Yes you beat me to it, my thoughts exactly.

 

[Raul]

Our set up is …

PVC van
2 x lead acid leisure battery
1 x 120 solar panel

We can just about manage (UK summer/France October) 3 days off grid The 4th day depletes the battery too far.

Is there anything we could do without swapping fridge to absorber yo run off gas that would give us 5-6 days comfortably off grid?

Assuming your leisure batteries are 100ah each, you can fit as much as 480w solar with a mppt controller.
Classic mistake most folk do is, Insufficient charging rate for off grid. In ideal weather, a panel will work within its parameters, but, the ideal conditions don’t last, so that panels parameters are not sustained. Most don’t account for this and drastically under panel their needs. Yes you can increase the storage, but once depleted, you still have to charge back.
My advise would be, as it stands with what you have, the best bang for the buck, will be at least 300w solar on the roof, and a good mppt controller.
I have 600w solar on the roof and run two compressor fridges. No problem so far. I added 230w solar portable when the second compressor went in the van.

 

[old-mo]

Mo, why not just get your solar/battery capacity increased, for the cost of changing your fridge (if it could be done) you could probably get a good lithium/solar set up.

Cheers Mel..... But to be honest I don`t know or understand what set up I have...

I have two battery`s under the drivers seat, presumably the leisure batteries, and two that look quite big solar panels... (Don`t think there is enough room to put bigger ones up there.)..

And the complicated as all get out electric boxes an elcb thingy`s in the wardrobe and a display that I have no idea what it is or does...

I do understand 12 v - 240 and gas fridges...

I cannot afford to be without electric, be it 12 volt or 240 through the on board 12v to 240v thing...

But I know we could manage with the fridge being on Gas...

Our other stuff is the normal to keep us happy ie TV/Radio (Which I think comes off the engine battery... LED lights, water pump and heater pump..

Hence I would love the 3 way fridge...

 

[Minxy]

eddievanbitz have you got any suggestions for Mo? Sensible ones!

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[Toady]

eddievanbitz have you got any suggestions for Mo? Sensible ones!

Great suggestion. Speak to Eddie and he will sort out what you need.

 

[old-mo]

eddievanbitz ........... You in bed yet..??

Or watching rugby...

Could you sort out my electrics or fit a new 3 way fridge...

Please PM me with an approx price...

 

[Minxy]

eddievanbitz ........... You in bed yet..??

Or watching rugby...

Could you sort out my electrics or fit a new 3 way fridge...

Please PM me with an approx price...

Don't think he'll do a barter for a battered old tea urn so you wallet moths might get upset when you disturb them.

 

[Grianan]

So managed to get a peek at current set up today.

We currently have
120W solar
2 x LA95 12V 95Ah(c20) 85Ah (c5) Varta batteries (assuming both the same, we can only see one without removing drivers seat).
A cheap as chips solar controller.

 

[Hoovie]

Your Chip as Chips solar controller is a basic PWM Solar Controller. If you swapped that out for an MPPT Controller, you would get an instant benefit of upto 30% more charging from the solar.

to be technical, a Solar Panel voltage is a few volts more than the battery volts.
As an example, a 120W panel at full power might put 6A current into the Controller at 20V. A PWM will transfer that current into the battery, so you are getting 6A, but only at around 14.4V maximum, which is around 86W, not 100W, as it just chops the voltage down from 20V to the 14.4V.
An MPPT Controller will convert that excess Voltage to extra Current - so instead of being 6A at 14.4V, you will get around 8.33A at 14.4V.
the exact extra benefit depends on a combination of what voltage the panel is running at and what voltage the battery is currently at, but you will gain power from an MPPT over an PWM except for a very tiny window of time, so overall always a good upgrade.

More Solar would be good if you are a summer camper. if you could get 200W or so on the roof, you should have more than enough to run the fridge during the day whilst also recharging the battery for the night. Wintertime, Solar is ornamental though.

I'd try those before looking at Lithium Batteries and definately before a 3-way fridge (making a retro-fit to a 3-way fridge would cost much more than getting Lithium!).
Make sure if you change to an MPPT controller it will support Lithium as a future-proof. Something like a Victron MPPT 75/15 would be good - under £100 for the BlueSolar version, work with any battery and support upto 220W

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[davidroxburgh]

I quite agree that a change of the solar regulator makes sense. For me I would go Votronic - On-Buy have a 220version - up to the same as the one suggested above cost £128 odd. Votronic used to go 165, 250,350 and then 430 I think so I guess this is a very recent version. They too support Li.

I am guessing the batteries are AGM? Can you use a phone to take a photo under the seat by lifting the seat as high as it will go slide it full back or forward and then try?

Does your van have an EBL or whatever? May I ask what van and age?

 

[davidroxburgh]

If you could manage both a new solar controller and a B2B - then both would have Lithium settings ready for the day you decoded to splash out - but meanwhile your batteries would do much better whether lead acid or AGM I think. If you will need help fitting those items, then arguments for lithium grow stronger, because if the seat has got to come off anyway when fitting the new solar regulator and B2B then the labour cost of changing the batteries would be less than as a stand alone job. I thought the report of wondering star above was a good testament to lithium!

 

[Raul]

That controller alone, turns your 120w panel into a 80w. Even worse, it’s not even a true pulse with modulator, PWM. A true pwm controller does 3 stage charging, this one is a single voltage chopper. It cuts the voltage of the panel and does constant voltage charging as long as receives power from panel.
You need a real mppt controller for the start, big enough to upgrade your 120w solar later.
I would recommend a victron 100/30 smart, that can charge Lithium as well, just in case you will upgrade later.

 

[Hoovie]

That controller alone, turns your 120w panel into a 80w. Even worse, it’s not even a true pulse with modulator, PWM. A true pwm controller does 3 stage charging, this one is a single voltage chopper. It cuts the voltage of the panel and does constant voltage charging as long as receives power from panel.
You need a real mppt controller for the start, big enough to upgrade your 120w solar later.
I would recommend a victron 100/30 smart, that can charge Lithium as well, just in case you will upgrade later.

Ref the 100/30 .... that supports 440W of solar, which can be a lot to fit on the roof just in terms of available roof real estate. On my Motorhome, due to roof vents and bits & pieces, I could only fit 270W nicely (I like it to look symmetrical as well ) so instead of the 100/30 I had on my last camper (the 100/30 is a great controller, not disputing that at all ), I opted this time for a 100/20, which support upto 290W (perfect for my roof array). And also fitted a second 100/20 which goes to an SAE connector in the rear valance, into which I can fit a cable from Portable Panels. Those panels can be positioned and angled as well which could be a benefit.

Just an alternative idea (especially considering a pair of 100/20s is only a little more expensive than a single 100/30)

 

[stewartwebr]

I think that MORELO were fitting the Dometic 10 series compressor but might be moving over to something else soon, according to the Dometic specification for the 10 series compressor the consumption for a 24H period @12v seems to be in the range 40ah to 70ah so OK a bit more than stewartwebr suggested but he makes two very valid points, the first being the way the fridge/van electronics handles the switching of the small inverter that is dedicated to the fridge and secondly when you have 840ah of LiFePO4 and no doubt a roof full of solar you don't really worry that much.

EDIT actually MORELO may already be using the Siemens fridge freezer in the Empire Liner and it is is possibly more efficient than the Dometic offering.

Hi Martin, yes you are correct in that we have the Seimens fridge freezer, it is on the Morelo “secret” list which I am sure you shall have a copy of. It is very very efficient and effective and no ugly grills.

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[Grianan]

davidroxburgh what is an EBL?
Van is 2018 PVC Globecar Campscout.

Is it worth doing B2B as well as changing to an MPPT controller?
That controller seems like a no brainer.

If we could get to position Hoovie said of being able to run fridge and charge battery I’d be over the moon.

 

[Raul]

Ref the 100/30 .... that supports 440W of solar, which can be a lot to fit on the roof just in terms of available roof real estate. On my Motorhome, due to roof vents and bits & pieces, I could only fit 270W nicely (I like it to look symmetrical as well ) so instead of the 100/30 I had on my last camper (the 100/30 is a great controller, not disputing that at all ), I opted this time for a 100/20, which support upto 290W (perfect for my roof array). And also fitted a second 100/20 which goes to an SAE connector in the rear valance, into which I can fit a cable from Portable Panels. Those panels can be positioned and angled as well which could be a benefit.

Just an alternative idea (especially considering a pair of 100/20s is only a little more expensive than a single 100/30)

Depends, my van PVC I designed it for off grid. I have 600w on the roof on a 100/50 controller, and 230w portable on a 100/20. That enables me to run two compressor fridges, throughout the year.
It’s all down to the OP budget, and what space is available on the roof. I agree two 100/20 is better as you will have two independent mppt’s.
The 100/30 is a nice middle ground choice, no to expensive, but in the same time versatile in terms of its use. You can load a 100/30 with one panel, yes a 120 cell half cut now are in the 450w territory.

 

[Hoovie]

davidroxburgh what is an EBL?
Van is 2018 PVC Globecar Campscout.

Is it worth doing B2B as well as changing to an MPPT controller?
That controller seems like a no brainer.

If we could get to position Hoovie said of being able to run fridge and charge battery I’d be over the moon.

Well .... What I can tell you is that I used to go to VW Shows in various UK locations, but mainly Leeds or more north to Trade. Would arrive on either Thusday Evening or Friday Lunchtime. And pack up Sun Afternoon.
Had 200W on the roof, a Waeco CRX-50 12V Compressor Fridge, and 200Ah of Lead Acid. No Hookup.

The batteries would get use overnight of course, but would be full again by lunchtime. In fact I would use my little 500W Induction Hob to boil kettle for drinks during the day instead of using the gas hob to avoid wasting potential solar power, and also use a slow cooker sometimes for the same reason.
I honestly use to leave back for home on Sunday afternoon with the batteries as full as when I arrived.


Now is a B2B worthwhile. Without a doubt it will charge your batteries better than a basic relay-based Split-Charge. It will also treat your batteries better and you will also certainly get a longer life from them. In many ways, a B2B vs Split-Charge Relay is a similar argument to MPPT vs PWM, except the cost of upgrade is a fair bit more as you will almost certainly have to run more cables and work out how to disable the existing charging circuit. (an PWM to MPPT swap is purely a device swapout)


PS. an "EBL" is a Schaudt ElektroBlock device. popular on german vans.

 

[Hoovie]

I see Seimens do a A+++ Fridge/Freezer that uses just 84KWh/Annum. That is excellent for a big Fridge Feezer
My little 94L Fridge I fitted in my Camper only had a little ice-box but it also used 84KWh/Annum.
84KWh/Annum on an AC unit works out as, including probable inverter losses, to around 1Ah/Hr, so a very respectable 24Ah/Day.

 

[Jamesh]

Don't think he'll do a barter for a battered old tea urn so you wallet moths might get upset when you disturb them.

He did do some work for Tim Vine, John Bishop and MacIntyre..... But not sure about you, going by your jokes....

Cheers James

ps I actually like your jokes (most of them!)

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[paddymcc]

I think that your existing solar controller supplies both leisure and starter battery. I've a feeling that the Victron units only supply one battery (ie leisure) and so you would need to fit a battery master as well to supply the starter battery. The Votronic units supply a main charge to the leisure and a bit on the side to the starter so it might work out cheaper. Votronic are fine for lithium if you want to future proof.

 

[Grianan]

I think that your existing solar controller supplies both leisure and starter battery. I've a feeling that the Victron units only supply one battery (ie leisure) and so you would need to fit a battery master as well to supply the starter battery. The Votronic units supply a main charge to the leisure and a bit on the side to the starter so it might work out cheaper. Votronic are fine for lithium if you want to future proof.

Why would it be preferable to supply the starter battery too?
We don’t think the solar touches the starter battery - that is under the passenger floor whereas the leisure’s are under the drivers seat - Can’t see a link between them.

 

[Richard n Ann]

Why would it be preferable to supply the starter battery too?

Because it will discharge after a few weeks on it's own, but we use the van radio too.

 

[davidroxburgh]

Hi Minxy Girl had several Globecars I think so would know more about their split charge relays. I know you have a compressor fridge but is your heating gas or diesel? if the latter I think you would need lithium to get to 5 days but if heating is gas then with both the solar regulator and B2B and a good drive before stopping I think you would be there.

If the existing batteries are AGM (they looked like it but see from your van spec) then I know the 2 Votronic units I suggested have 2 AGM profiles and at least 1 lithium profile. The Victron ones may well do but I am not familiar with them.

The complexity and costs of fitting B2B are linked to the van set up thickness of wiring Etc. Hence the question about EBL as I think that would be relevant.

The next step will depend on whether you will DIY or if not choose who to go to?

 

[Sapper520]

Why would it be preferable to supply the starter battery too?
We don’t think the solar touches the starter battery - that is under the passenger floor whereas the leisure’s are under the drivers seat - Can’t see a link between them.

Our solar is connected to one of the controllers in the photo below. I‘ve read what people have to say about them (frankly it’s way too technical for my understanding) but it’s working fine for us. 130w panel, 2 x 110 batteries with the controller currently split 70% leisure / 30% vehicle.

Also when on EHU leisure and vehicle batteries receive charge.

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[paddymcc]

Why would it be preferable to supply the starter battery too?
We don’t think the solar touches the starter battery - that is under the passenger floor whereas the leisure’s are under the drivers seat - Can’t see a link between them.

As Richard and Ann said it ensures that the starter battery doesn't go flat if you have a solar panel. There will be a connection between starter and leisure battery as that's how the leisure battery is charged from the alternator when the engine is running. It's likely that it is via your electrical box of tricks, in my case an Electroblock but I don't know what Globecar uses. Mel will know I suspect.

 

[Hoovie]

whether a trickle charge to the starter is needed does depend on how you use your vehicle. If you don't drive it but it stays parked up for more than a month, then it can be very useful. If you drive it on a weekly basis or more, than not really required.
Some Motorhome electrical setups do this as standard, some don't.

Votronic Duo controllers are quite good and have a trickle feature, but that is limited to 1A, so if you are want to do this to make up losses from using a dash radio powered by the starter battery when parked up I don't think 1A will quite cut it.
The Victron MPPTs don't have this feature available.

Note that solar controller trickle chargers only work with solar charging, so if you want a way to maintain the starter from any source (e.g. Solar OR EHU), then you need an independant trickle charger, not one built into a solar controller.
The Battery Master from VanBitz is quite popular, but note that it doesn't work with Lithium properly. Votronic do one which also is not Lithium compatible and is very expensive for the diode in a box you get. Sterling also do a maintainer, but yet again, no Lithium compatible.
The best option on the market, IMO, is the Ablemail AMT-12. This is, as far as I am aware, the only Lithium (and Smart Alternator) compatible battery maintainer on the market and is also programmable so you can chose how much 'trickling' you do (you just change the on and off duty cycles to increase or decrease the average trickle current).
I have mine set to a higher current trickle to compensate for the losses incurred if I use the dash radio (powered by the starter) set to come on without the ignition key.

 

[Sapper520]

whether a trickle charge to the starter is needed does depend on how you use your vehicle. If you don't drive it but it stays parked up for more than a month, then it can be very useful. If you drive it on a weekly basis or more, than not really required.
Some Motorhome electrical setups do this as standard, some don't.

Votronic Duo controllers are quite good and have a trickle feature, but that is limited to 1A, so if you are want to do this to make up losses from using a dash radio powered by the starter battery when parked up I don't think 1A will quite cut it.
The Victron MPPTs don't have this feature available.

Note that solar controller trickle chargers only work with solar charging, so if you want a way to maintain the starter from any source (e.g. Solar OR EHU), then you need an independant trickle charger, not one built into a solar controller.
The Battery Master from VanBitz is quite popular, but note that it doesn't work with Lithium properly. Votronic do one which also is not Lithium compatible and is very expensive for the diode in a box you get. Sterling also do a maintainer, but yet again, no Lithium compatible.
The best option on the market, IMO, is the Ablemail AMT-12. This is, as far as I am aware, the only Lithium (and Smart Alternator) compatible battery maintainer on the market and is also programmable so you can chose how much 'trickling' you do (you just change the on and off duty cycles to increase or decrease the average trickle current).
I have mine set to a higher current trickle to compensate for the losses incurred if I use the dash radio (powered by the starter) set to come on without the ignition key.

My Sunlight van came with a built in charge to both Leisure and vehicle (according to the user manual) when on EHU. One of the things I asked the dealer to do was to rig the Solar up to charge the vehicle battery as well (as per the photograph above) when not on EHU.

I take it a Battery Master would be surplus to requirements in my case, with charge going from EHU and / or Solar?

 

[Hoovie]

My Sunlight van came with a built in charge to both Leisure and vehicle (according to the user manual) when on EHU. One of the things I asked the dealer to do was to rig the Solar up to charge the vehicle battery as well (as per the photograph above) when not on EHU.

I take it a Battery Master would be surplus to requirements in my case, with charge going from EHU and / or Solar?

sounds to me like you got it covered

 

[Minxy]

Hi @Minxy Girl had several Globecars I think so would know more about their split charge relays. I know you have a compressor fridge but is your heating gas or diesel? if the latter I think you would need lithium to get to 5 days but if heating is gas then with both the solar regulator and B2B and a good drive before stopping I think you would be there.

Steady on ... I've only had two Globecars!

As Richard and Ann said it ensures that the starter battery doesn't go flat if you have a solar panel. There will be a connection between starter and leisure battery as that's how the leisure battery is charged from the alternator when the engine is running. It's likely that it is via your electrical box of tricks, in my case an Electroblock but I don't know what Globecar uses. Mel will know I suspect.

Our Globecars had the Schaudt Electroblock EBL 119 which didn't have a provision for sending any of the solar input to the cab battery, just the hab ones, this explains what I did when I installed my solar panels and connected them up to charge both cab and hab batteries:

Globecar Campscout - Services & AV

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