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hello every one. I am a new member, just joined today. I am hoping one of you can help me with a problem I have on our CI Carioca. The leasure battery has gone flat and it does not appear to be charged by the charger. Is it bcause the battery has gone too flat and the charger output is not great enough to charge it up. I hope this makes sense and that some one can help. :(
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The onboard charger will not charge the leisure battery if it is flat. You may be lucky and restore it if you use a suitable independent charger- the onboard charger will not charge either the vehicle or leisure battery if either fralls below 10.7 v.

This has been my experience and I am sure some of the more informed members will correct me if I'm wrong!

It's all a learning process- if we're fortunate!! ;-)

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First off you will need an electrical meter.


Then you can check the output of the charger it should be at least 13.8v.


No output might mean a blown fuse or problem with the charger.


A dead battery is usually a scrap one, they just don't recover if they go dead flat.


So if it's a dud battery no amount of charging will bring the voltage up, sometimes they will appear to

charge up but the capacity is very much reduced.


Make voltage checks at the battery terminals, test the battery voltage with it disconnected, check the charger output by metering across the battery terminals with the battery disconnected.


If you find a fault it's tarck it down time!



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First, how do you know the battery is flat? Is it just because the on-board electrics don't work when not on hook-up? So, do the on board electrics work when on hook-up?


If the answer to the last two questions above is yes, find the battery and look for a large fuse carrier nearby. When you find that, disconnect the mains, remove the battery positive connection, then the negative and, just in case, keep them separated, and the positive clear of anything conductive. If possible, check the electrolyte level. If the battery is sealed, gel or AGM type, you won't be able to do this. Inspect the terminals and their clamps, and carefully clean and lightly grease.


Take care with the battery, they are very heavy, and contain acid. It is a good idea to wear gloves when handling batteries. Especially take care with metal tools as, although only 12V, even a partially discharged battery will give a huge spark if you accidentally bridge the terminals with anything conductive, potentially sufficient to melt bits off whatever comes into contact with them. If it happens, don't grab the bridge with bare hands, it is likely to be quite hot! That's where those gloves are useful!


If you don't have a volt meter, or a multimeter, it would be a good idea to get one, and check the battery voltage after it has been disconnected for a couple of hours. If you get over 12.5 Volts it is reasonably charged, 12.8 = full. If 12.0V it is flat, and if lower than 12V it is in the danger zone. They will drop to 10 or below, but at those voltages are liable to suffer damage unless quickly re-charged.


Now remove the fuse from the carrier and inspect/test it. Check its capacity against your handbook: it may have been replaced with one of too low Amperage. It may well have failed, which will prevent charging and supply. If defective, replace with a new fuse of correct capacity, re-connect negative, then positive, connections, reinstate mains power, and re-check the voltage across the battery terminals. You should now see something near 14V, indicating the charger is working.


If you don't, assuming the on-board electrics are working, you have a wiring fault between charger and battery, so will need to trace the wiring looking for damage or a loose connection.


If the on-board electrics are not working, check the mains switch is on, and that any circuit breaker feeding the charger circuit on the mains side, and any switch on the charger, is on. If you still get nothing, it may be a duff charger, or a wiring fault on the mains side. Don't forget to disconnect the mains hook-up before doing any tracing of mains circuits!


It is just a matter of checking each function methodically, and working through the possible areas of failure one at a time down each system. If you are unhappy checking the mains side, get an electrician to do it for you. Let us know how you get on. There are others far more knowledgeable then me, who will be able to give more specific advice if required. Good luck.

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Beg steal or borrow a battery charger and get some charge into it to raise the voltage back above 10.5 volts and the onboard charger will re-enable its output and start doing its job again. You could try starting the engine and try charging from the altermator to bring the volts up. ( Do not rev the engine - you might and probably will blow a fuse).


It probably appears totally flat as below 10.5ish volts the battery is disconnected from supplying any loads. Below around 8 volts ( cannot remember exact voltage for system used by CI) the on board charger will not switch on its output. This is a safety feature.


If this fails to work then follow advice in previous posts, but I think it will work.


You then need to work out if the battery has failed or what caused it to go flat. I suspect the standby drain from the electronic control panel and water heater are the problem with a drain of about 50mA and you have left the van idle for too long. I suggest you fit a switch in series with the negative lead from the liesue battery so you can isolate it when laid up for long periods. Also check you have not left anything switched on especially the gas heater fan as for some strange reason may be wired directly to the battery positive feed and not turned off by the control panel and master relay.


Hope this helps.


You battery will have suffered reduced life as a result of being run flat and hopefully you have caught in time for damage just to be small reduction in life and capacity. The newer it is the more chance it has of recovering. After it is charged again, check electrolyte levels, top up if required and give it a good charge for a few days.

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Guest 1footinthegrave

All good advice, the only thing I'd add is they do not last forever, and batteries vary in the amount of charges / and discharges cycles they give, some brands will give up far earlier than others, new ones I recently purchased quote 400 to 500 cycles, some will give considerably less, but a battery can just suddenly give up the ghost, like others have said a cheap digital meter then set it to the DC voltage range and it will tell you instantly if the charger part of your onboard electrics is working, plenty on Ebay such as this cheap and cheerful one at £3, yes I know £3, but I bought one similar and it does the job ! !



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rocksteady - 2012-12-05 5:23 PM


hello every one. I am a new member, just joined today. I am hoping one of you can help me with a problem I have on our CI Carioca. The leasure battery has gone flat and it does not appear to be charged by the charger. Is it bcause the battery has gone too flat and the charger output is not great enough to charge it up. I hope this makes sense and that some one can help. :(


Hi - welcome to the Forum. I'm glad Brian and Brambles have replied to you - they are the experts in this type of thing! However, from a completely non-technical point of view, when I purchased my CI, I was not told about another fuse, completely separate from the fuse box. In my CI, it is situated underneath the sink, on the inside of the 240v external plug. I may be completely wrong, but it's worthwhile checking. Best of luck,


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Wo Wo, hold on there!! Take the blinkers off.


1 Get a multimeter, digital is best

2 Connect it across the leisure battery terminals.

3 START THE ENGINE and run on fast tick over

The Split Charging should work and your battery volts SHOULD rise very quickly to at least 12 volts then continue upwards towards 14 after time. If no volts go in search of blown fuses.


4 Once you have established that the Split Charging works and have got the battery volts up to 12 or more then connect the mains hookup, switch on the charger and turn OFF the engine. The voltage SHOULD continue to rise towards 14 ish because of the built in hookup charger.


Only after you have done these basic tests can you progress.


Good luck




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  • 1 month later...

:-D :-D



I believe I have found some people who actually know what they are talking about,

I have an old style Auto-trail Mohican and have had problems with the electrics for years. I have spent around £2k trying to get it sorted and cannot afford another cowboy.

I thought it was sorted for the past two years, but now I have discovered something......


I am rebuilding, and recently had an 'expert' remove my 3 way fridge. Not only did he leave me with a gas leak (gas now turned off until further notice) but also told me that the reason my fridge had never worked on battery whilst driving was because it had been disconnected and the wire used to run all the 12 volt from the cab battery!!

So that will be why the lights didn't go out when I started the engine and why I have had to replace my cab battery three times!!

This wire has now been removed.


I think I am in trouble.


But, thanks to you guys, I have now ordered a multimeter and will check the leisure battery and see if it is charging before I do anything else. But I have looked and cannot find any large fuse box. The only fuses are in the box under the sofa where all the wires go, and those fuses are fine.

When other people have worked on my electrics they have always said things like "There should be another fuse box somewhere". But no one ever found it.


I have a sinking suspicion that I may just have to remove all wires and start again - so please watch this space as I will be asking many more questions!

But thank you - I am so pleased to have found this site, this page, and people who could actually help.

:-D :-D

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