Compressor fridges

[olley]

Our pvc has a compressor fridge and after our first weekend away without power I would rather have gas.
Swift have fitted a derisory 20watt solar panel which in sunshine produces about 1amp, the fridge takes about 3amps so even though its not running all the time it still deletes your batteries over a weekend.

The answer is more solar, lots more, but thats a job for the winter, in the meantime I have bought a 100watt panel and really cheap solar regulator, the panel will simply sit on the ground and that will do for the Lincoln show and maybe the Malvern.

The fridge it's self is fine, although a bit small, still it keeps our lce lollies nicely frozen

 

[Blue Knight]

What batteries do you have fitted Olley?

 

[Nasher]

I have a Waeco CRX-50 fridge, no solar, a 110ah battery and have never had a shortage of 12v over a long weekend

I also use lights, tv, water pump & my diesel hob/heater needs a bit of power to fire up

 

[olley]

2 brand new 100amp Hankook agms. Bk.

 

[Blue Knight]

2 brand new 100amp agms. Bk.

What's your charger size and does it have a 14.7v charger setting for AGM. Perhaps I'm jumping the gun here but your charger may not have the metal to support AGMs correctly.

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[olley]

No question that the Sargent charger isn't up to the job, it's only a 20amp and has no settings at all, it's just a basic flooded cell charger but it should still get them to 90% of fully charged I would have thought.

 

[Blue Knight]

I've just looked at the Swift tech section and it looks as if your Swift Select is equipped with a Sergent PX300 Charger.

The brochure does say that it'll be compatible with AGMs but after reading the actual data I would say not.

The max charge voltage is 14.4v so one battery alone will take an age to charge and will only ever achieve 80% of its stated capacity; adding a second battery will kill it.

See below - I don't think your problem is the fridge but the battery set-up (and the charger).

Also, your engine alternator is only likely to be pushing out 14.4v so that's not going to help the AGM batteries much either.

 

[olley]

As I said the charger isn't up to the job. After arriving on Friday evening by Sunday the batteries were down to 12volts, no telly just a few led lights and the fridge. Around 36 hours at say 2amp per hour that's 72 gone.

 

[Blue Knight]

As I said the charger isn't up to the job. After arriving on Friday evening by Sunday the batteries were down to 12volts, no telly just a few led lights and the fridge. Around 36 hours at say 2amp per hour that's 72 gone.

Sorry to say this but your whole system (compressor, AGMs and a sub-standard charger) is not fit for the purpose of 'off-griding'. In this instance it's clear that the Swift set-up needs constant life support from EHU to function effectively.

You'll need to get a few bits changed if you want to off-grid while adding a 100W of solar to thay set-up will just not cut it.

Did the dealer advise you on this combo as I would go back to them and have a word!

 

[olley]

This is just a test bk, can we get on with a pvc from using a RV (still got it) if we can then I will do some mods, new battery charger, proper solar regulator, 200watts solar. Upgrade weight etc.
Maybe sell the RV next year? Just fitted 3 x 180ah hab batteries to that.

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[Blue Knight]

This is just a test bk, can we get on with a pvc from using a RV (still got it) if we can then I will do some mods, new battery charger, proper solar regulator, 200watts solar. Upgrade weight etc.
Maybe sell the RV next year? Just fitted 3 x 180ah hab batteries to that.

That sounds like a cunning plan sir.

Good luck Olley with whatever you decide.

Andrew

 

[TheCaller]

I suppose Swift & others like them know their market & know what sells, but my impression is that what they are making are caravans with a motor attached to propel them from one EHU point to the next.

I fully understand why converters like the Sargent kit & they have some innovative features, but they are unsuitable for any vehicle that is going to be more than 24hrs away from a hook up, especially a vehicle with a compressor fridge.

Maybe DVLA are right after all - they are all motor caravans as far as DVLA are concerned.

 

[olley]

I guess most of the problem is me, we go to shows in the RV, don't need to dump don't need to fill with water. Tv all day, showers, heating if we want, power no problem start the genny, now everything runs out.
Either I get used to the change with a few mods or flog it.
I can't see the point of a compressor fridge in a motorhome.

 

[Kannon Fodda]

you’ll need a B2B charger. The standard systems in MHs aren’t able to pull enough juice from the alternator as once the motor battery is full that starts reducing demand with smarter alternators that won’t see the leisure demand. At present even a long drive and you could get to your destination less than full

as far as pvc electrics go it does seem the main manufacturers see them as weekender vehicles. You’ll. stay off grid for a night at most otherwise you’ll be on ehu somewhere. I’ve spent a fortune to get off grid capable electrics yet here I am on a site plugged in.

(no idea why this is in bold font)

 

[tonyidle]

(no idea why this is in bold font)

It does that when you're talking sense .

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[csd4t]

Watching this thread with interest, just done 5 nights at new forest, by day 4/5 no fridge and batteries showing 9v.
PVC with 100w panel, Sargent EC325, two 85amp lead acid batteries.

 

[Deneb]

PVC with Isotherm compressor fridge, 2x 90Ah batteries, 200W solar, Votronic MPP regulator and B2B.

Love our compressor fridge, would never go back to gas. Currently touring Scotland, been on EHU 2 nights in the last 16 days, and battery SOC never less than 82%

 

[olley]

Just had a chat to Sargent very helpful guy, only way is to turn of their charger off and fit a new charger with a battery master to maintain the engine battery, their solar charger can handle up to 150w but again no AGM setting.
Another annoying "feature" is start the engine and all hab circuits turn off except charger and fridge, but stop the engine and they don't come back on and you lose power to the fridge until you press the main power button. There is a sensor wire from the engine in the EC600 but he can't tell me which one it is so I shall have to hunt for it.

 

[Blue Knight]

Just had a chat to Sargent very helpful guy, only way is to turn of their charger off and fit a new charger with a battery master to maintain the engine battery, their solar charger can handle up to 150w but again no AGM setting.
Another annoying "feature" is start the engine and all hab circuits turn off except charger and fridge, but stop the engine and they don't come back on and you lose power to the fridge until you press the main power button. There is a sensor wire from the engine in the EC600 but he can't tell me which one it is so I shall have to hunt for it.

Did he advise you to ignore all of the 'AGM compatability' advice that is printed in the Swift manual. Truly shocking!

Also, I've done a few figures Olley concerning your weekend Ah usage and I reckon you used close to 45Ah and not 72Ah as you thought previously.

The PX300 Charger is most likley only capable of attaining a 75% SoC with those two big AGMs of yours; therefore, with a 12v reading (50% SoC or 100Ah) after 48-hours then IMO you're not using 70+Ah but 40 to 50Ah, max, i.e. 150Ah - 100Ah.

As you say, make a few changes to the system and the fridge will be just fine and dandy.

 

[DBK]

As I said the charger isn't up to the job. After arriving on Friday evening by Sunday the batteries were down to 12volts, no telly just a few led lights and the fridge. Around 36 hours at say 2amp per hour that's 72 gone.

I don't think your charger is the main issue. We have a compressor cool box which uses a similar amount of current. With 180Ah of batteries I wouldn't expect to last much more than two days without needing to do something about charging the batteries. Normally, this isn't an issue as we have 200W of solar but on a wet weekend they aren't going to do much. We also have a diesel heater which takes quite a lot of power too.

After a trip down the Mosel late one year I fitted a B2B as the sun was too low in the sky to do much good and we were only driving a short distance between overnight halts. It isn't often realised just how much driving you have to do to charge your leisure batteries unless you have a B2B fitted. It can take several hours so depending how far you drove to your weekend stop it is possible the batteries were not fully charged even when you arrived - leaving aside the issue of the charger probably not having the correct charging profile for the AGM batteries.

What I'm trying, in my rambling way, to explain, is even with a better charger you will struggle to last over a weekend. Solar will help of course but not in winter or when it is cloudy. More batteries will help but scope may be limited in a PVC. A B2B and then if the budget will stretch a couple of lithium batteries would help a lot.

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[Blue Knight]

One of the big issues with PVCs these days is very often the people selling them have not got the first clue about their technical spec.

My own supplying dealer is the main distributor for Globecar in the UK and yet they don't have a scoobies about the vehicles they sell.

I now have three hab batteries fitted to help support our needs and don't ever need EHU unless it's late October onwards in the Highlands & Islands and, even then, it'll only be required every 4-5 days with travel inbetween. It has some fairly good electrical gear to start with though.

Kannon Fodda has made some great mods to his Autotrail to make it a very usable bit of kit but, IMO, it's just a shame that any UK model needs to go through a costly upgrade just to get it fit for purpose. The owner has already paid once for the Sergent equipment and then has to pay again to get decent gear that works for off-grid camping. If the manufacturers got their doo-doos together then they would realise the stuff they were peddling was not fit for purpose.

 

[Blue Knight]

They are good at marketing the off-grid life though:

 

[sciac2001]

Although initially being stunned that the pvc that we had purchased did not run on gas - we had obviously not done our proper research and unbelievably, even the salesman did not know - we are delighted that this is indeed the case.
Of course, it has meant that we have had to splash out on a decent wattage in solar panels but the system has proved a godsend as we are totally now unaffected by altitude touring, blow-outs during gusty periods or having to clear sooty deposits.

 

[CazPaul]

Sorry to say this but your whole system (compressor, AGMs and a sub-standard charger) is not fit for the purpose of 'off-griding'. In this instance it's clear that the Swift set-up needs constant life support from EHU to function effectively.

You'll need to get a few bits changed if you want to off-grid while adding a 100W of solar to thay set-up will just not cut it.

Did the dealer advise you on this combo as I would go back to them and have a word!

Great advice Andrew, if we ever go down the PVC route I will be after your input please.

 

[olley]

I have been trying to find an installation/wiring diagram for the The Sargent EC 651 fitted to our Swift, it has a habitation relay in this unit and a wiring diagram or installation manual which would show how which wire to remove to turn it off. No success so far.

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[olley]

I don't think your charger is the main issue. We have a compressor cool box which uses a similar amount of current. With 180Ah of batteries I wouldn't expect to last much more than two days without needing to do something about charging the batteries. Normally, this isn't an issue as we have 200W of solar but on a wet weekend they aren't going to do much. We also have a diesel heater which takes quite a lot of power too.

After a trip down the Mosel late one year I fitted a B2B as the sun was too low in the sky to do much good and we were only driving a short distance between overnight halts. It isn't often realised just how much driving you have to do to charge your leisure batteries unless you have a B2B fitted. It can take several hours so depending how far you drove to your weekend stop it is possible the batteries were not fully charged even when you arrived - leaving aside the issue of the charger probably not having the correct charging profile for the AGM batteries.

What I'm trying, in my rambling way, to explain, is even with a better charger you will struggle to last over a weekend. Solar will help of course but not in winter or when it is cloudy. More batteries will help but scope may be limited in a PVC. A B2B and then if the budget will stretch a couple of lithium batteries would help a lot.

Understand DB going to hold fire at the moment and have another weekend away and see if we are happy with the PVC its self if we are then I will spend some cash.
Been doing some scoping out to see how easy or not some of these mods would be.
Had a look at your BTB and I can fudge my wiring under the floor from the engine battery to the drivers seat and then under the floor again at the back of it, the floor behind the driver is built up about 4" and then theirs the double seat with the hab batteries underneath. Space is not a problem as theirs nothing in there except my two AGM's and some air pipes for the heating theirs even room for another AGM on end if I wanted.
Had a measure up for solar and I can get 3 100watt on the roof, although I think 2 for now, the route down would be close to the edge of the roof and down the drivers pillar and into the raised floor same as the BTB wiring with the reg under the double seat.
For a proper mains charger I probably have to run under the van but it might be possible get under the front edge of the shower which leads to the fixed bed and incoming EHU.

So I now have no change out of £600-£700.

 

[Lenny HB]

I really don't understand why more & more manufacturers are changing to AGM batteries they are pretty useless for leisure use and fail in a very short time. On our current van I ditched the AGM and fitted 3 Gels and have never had any battery problems.

 

[Kannon Fodda]

Main upgrades to worry about would be a B2B and the solar. Battery types might help, either GEL or even better Lithium if you have deep pockets, so you can really use most of that capacity - Lead acid and AGM dont do regular deeper discharge or high loads.

I still only have 100W solar, but the Victron MPPT controller will be a lot more efficient than the dodgy Autotrail effort, and offers a number of different charging profiles so you can select battery types. Much better than just a keep trying to whack energy into the battery when it might not be needed when say on my drive, yet the battery master ensures engine is also topped up so the alarm can't deplete it. That didn't mean much change out on wiring as with only 100W it didn't overload the Sergant PSU charger/12v/230v all in one thingy.

The big change was the Sterling B2B. I know the standard wiring to the Sergant relay was disconnected - a fuse behind the driver's seat was pulled - which stops back feed weirdness between the B2B and Sergant. The B2B has some big cables run from somewhere up front to the leisure battery as it will handle far more than the 12A max the Sargent allowed when driving along.

I don't have a compressor fridge, just the 3 way thingy. My original leisure stuff was so pants with a single 75Ah (yes that is all that was fitted) battery that I don't think it got a decent charge even on a couple of hours run from Surrey down the M3 to the New Forest. And that's the point the Sergant is usually that throttled to 12A max charging whilst driving that it's effectively incompatible with the OP's battery capacity.

But I didn't have the Sergant PSU charger/ 12v 230V unit replaced with a charger for when on hook up. Too much aggro needing then to mess with too much of the 230V / 12v habitation wiring. Although the Sergant thing only does one steady charge rate, flat rate up to 12A depending on what else is being drawn off, I figured if on EHU I have hours and hours for the batteries to refil. So why swap that out? The priority is the off grid top off of solar, or if you are driving only a shorter distance.

Without knowing your wiring and connections I dunno how much my experience would work for you. I left my upgrades to the experts, VanBitz, so don't know exactly how they did it.

 

[Langtoftlad]

Watching this thread with interest, just done 5 nights at new forest, by day 4/5 no fridge and batteries showing 9v.
PVC with 100w panel, Sargent EC325, two 85amp lead acid batteries.

9v ???
Surely that means your leisure batteries are goosed ?