Excessive Hab Battery Drain

Our recent trip to the Tiverton Balloon and Music Festival was a huge success with one exception.  On returning to our camper (2007 Nuevo EK 2 berth) we had no 12V power at all.  I had to start the engine at midnight (apologies if you were near us) so that we had enough light to make the bed and brush our teeth.  For the rest of the stay we had to run the engine for 30 minutes to get some charge into the hab battery but it only lasted a few hours even though the hab battery condition screen constantly said the battery condition was good. The battery is only 9 months old and is a 120ah model so It should not be faulty.

On returning home I have hooked up to the mains and charged the hab battery for a whole day using the on board charger.  All the 12V systems I am aware of are switched off but when I look at the hab battery drain screen all but one of the "boxes" are blacked out showing a high drain.  If I put all the internal lights on as well then all the boxes on the drain screen black out so I am assuming that the gauge is working properly.  Obviously if this high level drain is happening all the time it is little wonder that the hab battery is struggling, but I have no  idea what is drawing so much current when it should in fact be zero.

All suggestions gratefully received  

Is it possible that the fridge is running on 12 volt? It should not be on 12 volt with the engine stopped, but just maybe the isolating relay has stuck in the 'on' position (or the contacts of the relay have become welded together). Just a thought.

I'm not that familiar with the power control system in your van but I think with your age of Nuevo you could still have the radio on/off toggle switch in the habitation area. If you have the radio was connected to the leisure battery and even with the radio supposedly switched off it would draw quite a bit of current and flatten the battery in a few days. Maybe you've accidentally switched it and not noticed.

If that's not it you'll need to measure the current directly at the battery and start isolating circuitry till you find the culprit.

Peter

Just copied and pasted from my last posting
I think this has been mentioned in a previous thread but for new readers disconnecting the power for a few seconds and starting up again seems to cure it. Like all modern equipment with 'computers' inside they seem to need a re-boot from time to time.
Regards
Fred

Spospe wrote:Is it possible that the fridge is running on 12 volt? It should not be on 12 volt with the engine stopped, but just maybe the isolating relay has stuck in the 'on' position (or the contacts of the relay have become welded together). Just a thought.

I'm guessing this is the MES electrical system in which case you need both the engine to be running and the vehicle to be moving before the fridge operates on 12v, in any event the fridge is connected to the vehicle battery direct and to the leisure battery as well but via the split charge relay so it would have to be the split charge relay that was stuck and then the vehicle battery would flatten as well.

Peter

https://www.autosleeper-ownersforum.com/t11332-sigma-el-touch-screen-dislay#90095

The link above is to the thread mentioned by oldfred - I missed it when away for the weekend.

Sounds like a possible solution.

Peter

Our MES panel has no battery drain screen (06 so may be different panel) so maybe not an MES system

Many thanks for the responses so far.  I can confirm that it is nothing to do with the radio as we have replaced it with a modern "head" unit that is wired to a non ignition controlled feed on the vehicle battery so that it does not keep switching itself off every 20 minutes.

It is also unlikely to be the fridge as it is as Peter said that it only functions once the vehicle is in motion when operating on 12V.

However, pulling the main 50A fuse for a few seconds has cured the battery drain screen reading a high drain when all systems off, and it now reads a correct drain of zero boxes with all systems off and two boxes when all interior lights are on for instance.

This now leads me to ask that when the drain screen was reading high did this mean that there really was a high drain (remember the hab battery kept going flat) or was it just a high reading on the screen with no actual drain taking place meaning that I may still have a dud battery?

Tincataylor,

I think you are just about to answer your own final question..........your hab. battery is either going to hold up or it isn't.

There is no alternative but to drop an ammeter into one of the battery leads to see if there is a discharge or not, 'cos if there isn't......it's a duff battery and the voltage will drop anyway.
If there is current flowing, then you've got to find what's still switched on.

Derek

Derek,

The van goes into the garage tomorrow for a rapid discharge test on the battery and a drain test as you have suggested. 

What I will not be able to replicate is the possibly artificial drain reading that was present before the main 50A fuse was pulled for a few seconds.  Was this a real drain or not? Why does pulling the fuse cure the screen reading?  What caused this possibly false reading in the first place and how do I avoid it happening again? 

My own thoughts are that with all systems off the high drain reading had to be false as where could the current be going unless a short circuit was generating heat somewhere?

Well lets see what the garage say. Your newish battery could be U/S due to the fault  that  caused the battery to go flat.
Lets hope they can identify the original fault that may have cured itself.!

regards

Mike

Tincataylor wrote:Derek,

The van goes into the garage tomorrow for a rapid discharge test on the battery and a drain test as you have suggested. 

What I will not be able to replicate is the possibly artificial drain reading that was present before the main 50A fuse was pulled for a few seconds.  Was this a real drain or not? Why does pulling the fuse cure the screen reading?  What caused this possibly false reading in the first place and how do I avoid it happening again? 

My own thoughts are that with all systems off the high drain reading had to be false as where could the current be going unless a short circuit was generating heat somewhere?

Not having seen the fault, this is an intelligent guess. There will be an error in the firmware that operates the power system that will invoke this condition when certain circumstances occur (anyone that has this problem should think what happened or was done immediately prior to the problem occurring and see if they can induce the problem by repeating them). Its a long time since MES made this system and they still exist; there was a man (a year ago) who had something to do with designing the system but was never in when I called. AS have no knowledge of the system design as they bought it as a package so can't help.

Peter

I think the preceding condition that Peter was describing is actually the drop in operating voltage to the panel.
This appears to be the common factor in most of the reports and one that I have experienced myself.
It seems that the only reading sent wonky is the misreporting of the load as being high.

Luckily, a hard reset corrects the issue.

Derek

The garage has tested the battery and the tests show it to be in good condition and that there is no drain on the battery when all systems are off.  I have a loan battery for this weekend when we are going to the Upton Blues Festival and if everything works OK then there must be something wrong with the original.

However as the battery was purchases on line the supplier requires a copy of the invoice and a printed report from my local garage stating the battery is faulty before they will send a new one under warranty.  I will post the final outcome as soon as I know what it is for those who are interested   

Tinca

I bought a 1000ah cold-cranking battery from 'Performance-Batteries' on the net for the Land Rover, I started having trouble after 3 years & was just about to buy another, when I noticed the the warranty was FOUR years on their website, contacted them, they told me to take it to an independent motor shop, have it load-tested & supply a written report, luckily, my 'local' guy did this for me, I sent it off, & a day later, a new replacement arrived & they took the old one back, well pleased with this particular company & would heartily recommend them.

I though people might like to know of the successful outcome of this post.  My local garage prepared a report for me (in return for a few bottles of cider) stating that the battery was indeed faulty and unable to hold a charge. They also conducted a leak test to make sure the vehicle was not drawing current when everything was switched off.

I contacted the supplier who had a replacement battery with me the next day and the old battery collected the day after.  No fuss, just excellent service. 


As a result I have no hesitation in recommending www.advancedbatterysupplies.co.uk for both price and service for all your vehicle and hab battery needs,

Tincataylor