Leisure battery flattened by fridge!

[MartianTom]

Hi folks,

I know I'm going to sound really dumb, but I'm a newbie!

I've just got back from my shakedown trip in my MH. Spent 10 days touring around East Anglia. Wild-camped for 3 nights, but other than that I stayed on CCC sites. I'm letting myself in gently, as you can see

Anyway... before I set off I bought a brand new 85 Ah leisure battery, which was mainly going to be for running the fridge in transit. I had electrical hook-ups on all the sites, and on wild-camping nights I barely used the 12v at all.

In all, I covered 650 miles driving, and during all of that time the fridge was on. I got home today and checked the leisure battery - and it's almost flat!

I set out assuming that the trickle charge would keep the battery topped up, despite the fridge, and that the electrical hook-ups would also provide a charge. Have I got that seriously wrong? If so, what can I do to avoid this situation in future? If I spend more time wilding, then I can't see how I can avoid running the battery flat quite quickly if I'm using the fridge, unless I keep my daily miles to a minimum - which'll be a serious pain when I set off around Europe next summer!

Any advice would be greatly appreciated.

 

[David & Ann]

Hi folks,

I know I'm going to sound really dumb, but I'm a newbie!

I've just got back from my shakedown trip in my MH. Spent 10 days touring around East Anglia. Wild-camped for 3 nights, but other than that I stayed on CCC sites. I'm letting myself in gently, as you can see

Anyway... before I set off I bought a brand new 85 Ah leisure battery, which was mainly going to be for running the fridge in transit. I had electrical hook-ups on all the sites, and on wild-camping nights I barely used the 12v at all.

In all, I covered 650 miles driving, and during all of that time the fridge was on. I got home today and checked the leisure battery - and it's almost flat!

I set out assuming that the trickle charge would keep the battery topped up, despite the fridge, and that the electrical hook-ups would also provide a charge. Have I got that seriously wrong? If so, what can I do to avoid this situation in future? If I spend more time wilding, then I can't see how I can avoid running the battery flat quite quickly if I'm using the fridge, unless I keep my daily miles to a minimum - which'll be a serious pain when I set off around Europe next summer!

Any advice would be greatly appreciated.

From reading your post, I take it you have no 3 way fridge. Normally you should run your fridge on gas when wilding, on electricity when in a CC and on battery when driving. If you don't have a 3 way fridge, you have a problem. When driving the Alternator should be charging your battery. When on hook up your battery should also be charging. Perhaps some members with more knowledge with battery and electrics will be along to advise you.

 

[MartianTom]

From reading your post, I take it you have no 3 way fridge. Normally you should run your fridge on gas when wilding, on electricity when in a CC and on battery when driving. If you don't have a 3 way fridge, you have a problem. When driving the Alternator should be charging your battery. When on hook up your battery should also be charging. Perhaps some members with more knowledge with battery and electrics will be along to advise you.

Thanks for your response. Yes, it is a 3-way fridge. It was on 12v only when I was driving. Average electric hook-up was for 18 hours. Whenever I parked up or wilded, I put it on the gas.

 

[DTDog]

It sounds to me that the 12v side has been wired up wrong.

The 12v supply should come from the vehicle battery, not the leisure. And should be run through a relay which will only start to work once the engine is running (to allow the alternator to replenish the power taken from the fridge).

If it has been wired wrong and depending on how far you are driving, it might be just as easy to leave the fridge turned off while driving as it will retain it's cold for several hours if the door isnt opened.

 

[rienza]

There quite a lot of items that are 12 volt on a motorhome ie lights, pump, 12 volt TV ? These operate on 12 volt even if you are on hook up but then the battery charger should be constantly recharging the leisure battery whilst hooked up.

Firstly is your battery charger switched on ( refer to manual) and is it set to charge the leisure battery or the vehicle battery?

Having said all that the alternator should have kept the battery topped up when you have done that sort of mileage so you may have a problem.

 

[n brown]

this is quite simple to sort out.as said your fridge should run directly off the vehicle battery via a relay.the relay is there so you can't accidently drain the vehicle battery and only connects to the fridge when the engine is running and the alternator charging.get a smartcom relay from e bay and connect it up as shown,they're easy to fit honest!

 

[Firefox]

If you are on a hook up you are OK, the fridge should work off 240V and your battery should charge as well. But the fridge can flatten your leisure battery overnight if not, and you attempt to use the fridge off 12V. So use gas on the fridge (if available) when wilding.

Having said that, you said the battery was flat after your drive back. Did you leave the fridge on and check it some time after getting back, even a few hours of the fridge on 12V can flatten an 85A battery depending on ambient conditions. The only time the fridge should work off 12V is when you are running and the alternator is working. If it gets cold off 12V when you are stopped and not on a hook up, it shouldn't really be wired like that. It is usually wired off a relay to work when running, the same as your charge.

If it was flat immediately after your drive, check your charging system and leisure battery earth.

If you are going round Europe and doing wilding I would recommend 2 leisure batteries and a fridge which can run off gas.

 

[jezport]

Are you sure your charger is working?
Your batteries should keep charged from the alternator while driving.

 

[n brown]

where are you?someone in your area might be willing to give it a quick look

 

[MartianTom]

Thanks for all your replies everyone. All info taken on board.

Here's what I did:

Ran the fridge on 12v whilst driving.

Switched to 240v on each electrical hook-up.

Switched to gas only for wild-camping, and for any stop where I was likely to be away for over an hour.

I understood, as has been pointed out, that the 12v in transit supply comes off the vehicle battery, not the leisure battery, which was why I was puzzled. As far as I was concerned, I used the leisure battery very little: the water pump (not a huge amount), and very occasional lighting (I have an AA battery-operated reading lamp, which I mainly used).

I simply can't understand where that charge has all gone. Interestingly, when I checked the charge level on the day before my return journey (150 miles), it still showed full charge. If, for some reason, the wiring is wrong, and the fridge 12v is coming entirely off the leisure battery... then, considering the total miles for the trip, wouldn't it have gone flat before?

 

[n brown]

your 12v fridge element could be from @ 85w-135w so maybe your charger put enough back in the leisure batt to keep it up for the trip? gawd knows!you'll have to put a meter on the wires connected to the fridge to be sure where the power's coming from.if the voltage goes up when you start the engine then its right and you have a different prob

 

[MartianTom]

where are you?someone in your area might be willing to give it a quick look

I'm in Herne Bay, in Kent.

Just been and checked all the connections - all fine. I then switched on the 12v and the leisure battery level indicator showed 2/3 charge. When I switched on the water pump, however, it dropped immediately to 1/3. Same if I switched on the interior light. They were both working at vastly reduced capacity, too.

Am I wrong in assuming that a 240v electrical hook-up takes over all electrical functions from the leisure battery? (i.e. water pump and interior light) The interior light is very bright (though I don't know the exact wattage) and I had it on for a couple of hours on Sunday night - but I had a 240v hook-up that night.

 

[n brown]

2/3 capacity is pretty flat.when you hook up 240,it doesn't take over as such,your inbuilt charger just starts to charge the leisure batt,at what amps i don't know but they're often not very powerful.usually enough though if you start out with a fully charged batt and it's usually being charged off the vehicle or 240v,unless there's some heavy current draw,like a fridge or halogen lights etc. i think every camper owner should buy a cheap test meter,less than a tenner,for testing voltage and continuity

 

[Canalsman]

Do you have a multimeter? If not, you need to get one (at Maplins for example).

You need to be able to measure the voltage at the leisure battery terminals.

Connect the multimeter and then start the engine. The voltage will rise if the battery is being charged from the vehicle's alternator.

Next, stop the engine and connect the 240v hook up. Again observe the voltage. This should again rise if the battery is being charged off the mains.

Your fridge should have a light that shows if it's being run off 12v. This should only light up when the vehicle's engine is running. There is a relay (or should be) that prevents the fridge from drawing 12v from either the vehicle or leisure battery.

Don't be guided by the battery level indicator - they aren't particularly reliable.

Take a look here for some extra info www.marxrv.com/12volt/12volt.htm

 

[rienza]

As I asked earlier have you checked that your built in battery charger is switched on and that it is set to charge the leisure battery Martian Tom?

There is usually a switch which allows you to alternate between charging the leisure and vehicle battery. You would normally leave on leisure but could have inadvertently have been switched to charge the vehicle battery.

The switch is very often not obvious.

 

[Deleted member 207]

I'll preface this with a warning that not all 3 way fridges are wired up exactly the same - it varies according to the make/age of the fridge and also the vehicle builder.

For pre automatic ignition fridges (piezo/push button), they dont need a 12V supply to stay alight on gas, automatic ignition (you hear tick tick when lighting the gas) need a constant 12V supply which comes from (usually) the leisure battery irrelevant of whether the engine is running.

Some vehicle builders wire in the 12V supply to the fridge from the vehicle battery using the vehicle's charge indicator light to switch a solenoid, others use the same system but wire the fridge to the leisure battery - others just wire to the leisure battery without any regard to the vehicle alternator output so its easy to flatten the leisure battery within a few hours.

Some builders install "smart controllers" which sense alternator output or 240V input and then select the appropriate charging circuits.

So we need to know some details about the fridge and the method of recharging the leisure battery to give you a proper answer.

 

[Martin P]

What make is the charger on your van

 

[The Grand Wanderer]

Hi Martain Tom,
CI or Caravan International are part of the Triango Group the same people who make Autotrail. It may be worth while to contact Colin Treacher at in order to aquire a manual for your van's electrical system.

Auto Trail VR Ltd
Trigano House
Genesis Way
Europarc
Grimsby
North East Lincolnshire
DN37 9TU
Tel: +44 (0)1472 571000
Fax: +44 (0)1472 571001


As far as I am able to see the electrics are made by Nord Elettronica
May be they might send a manual.

However it is vital that you maintain your battery/ies by making sure they are full of acid. Over a period of time the acid evaporates or boils off and you have to refill them with distilled water. A battery that is dry will not hold its charge neither will it supply a full amount of ampheres or power. It is also important that all batteries are properly earthed, often over time the earth strap corrode and cause resistance, thus inhibiting their ability to charge properly. Also check that all contacts to the relays under the bonnet are clean and corrosion free.
Hope this helps you,
Wanderer

 

[MartianTom]

Aha!

Hi Martain Tom,
CI or Caravan International are part of the Triango Group the same people who make Autotrail. It may be worth while to contact Colin Treacher at in order to aquire a manual for your van's electrical system.

Auto Trail VR Ltd
Trigano House
Genesis Way
Europarc
Grimsby
North East Lincolnshire
DN37 9TU
Tel: +44 (0)1472 571000
Fax: +44 (0)1472 571001


As far as I am able to see the electrics are made by Nord Elettronica
May be they might send a manual.

However it is vital that you maintain your battery/ies by making sure they are full of acid. Over a period of time the acid evaporates or boils off and you have to refill them with distilled water. A battery that is dry will not hold its charge neither will it supply a full amount of ampheres or power. It is also important that all batteries are properly earthed, often over time the earth strap corrode and cause resistance, thus inhibiting their ability to charge properly. Also check that all contacts to the relays under the bonnet are clean and corrosion free.
Hope this helps you,
Wanderer

Thanks for that info, Grand Wanderer. I contacted Colin Treacher, but he was unable to help given the age of my bus! Thanks, anyway.

But.... this afternoon I took the leisure battery off to charge it. I then went out for a drive and noticed that the 12v light on the fridge switch didn't illuminate when the engine was running, even though the switch was on. This suggests to me that the 12v supply to the fridge was coming off the leisure battery after all, which would certainly account for its going flat so quickly - unless, that is (and I'm displaying my ignorance of electrics here, but so be it!), the leisure battery needs to be connected too to complete a circuit from the vehicle battery.

Seems odd to me that they would wire the 12v side of the fridge up to the leisure battery rather than the vehicle battery. If that's the case, though, is it a fairly straightforward job to rectify? Is that Smartcom relay all I need?

 

[Canalsman]

The absence of the leisure battery shouldn't make any difference to the fridge operation when the engine's running.

You now need to replace the leisure battery and see, with the engine switched off, if the fridge 12v light comes on.

If it does, then it isn't wired correctly and is drawing power from the leisure battery.

If you aren't comfortable with rectifying the problem yourself, a visit to a friendly (and recommended and knowledgeable about motorhomes) auto electrician would be advised. A motorhome dealer would also be able to sort this - but try and get a recommendation.

In either case, ask for a quote first ...