Question about replacing a cab battery??

[autorouter]

He said a reading of 12.4 was a full battery not under charge.

If there is not a smart alternator fitted, then it looks like there is a fault with the charging from the alternator. 12.4V is not by any stretch of the imagination a fully charged battery. Measure both the cab battery voltage and the hab battery voltage when the engine has been stopped for more than an hour, preferably while it's dark to avoid confusion from the solar panel contribution. Then start the engine and measure the cab voltage again, while the engine is running. The voltage should jump to over 13V, ideally more like 14.4V. That means the alternator is charging the cab battery. If it doesn't increase, then you have a charging problem.

Also measure the hab battery while the engine is running. The voltage should be similar, ie between 13V and 14.5V. That will tell you that the split charge relay is working OK or not.

Are you in a position to hook up mains power, so that the mains charger can charge the batteries? You should get similar results for the voltages. Note that the voltage while charging does not indicate the state of charge of the batteries. It takes a few hours of charge to bring them up to 100% from 12.4V.

 

[autorouter]

What happened to being able to trust the company you are dealing with? What can you do if you believe they are looking you in the eye, shaking your hand and telling you a pack of lies!?

Knowledge is power. Learn how to do the tests yourself, and how to interpret the results.

 

[Teasy2007]

Knowledge is power. Learn how to do the tests yourself, and how to interpret the results.

Our son is a Mechanic and he is bringing his battery testing equipment this evening so perhaps we will have a definitive answer then.

The only question will then be if, as we have protested, and Funsters have confirmed, there is something wrong how can I possibly convince the technician “I have 18 years experience and I know what I am talking about” to put it right.

 

[Googlebot]

We had the same from a Technician, I have been fixing them for over 20 years he said.

What have you fixed then? Oh, just took the fridge out and put it back in....

Still broken.

 

[autorouter]

Our son is a Mechanic and he is bringing his battery testing equipment this evening so perhaps we will have a definitive answer then.

I'm sure he'll sort your cab battery problem out, but remind him not to try the battery drop tester on the Gel batteries. They aren't designed for starting engines, and don't like high currents. If he's not used to motorhomes he might not know this.

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[Teasy2007]

Our son came round this evening and tested the cab battery. These are the two photos he took. The technician said the drain was 0.07 but the other photo shows that this is 0.79. He did not believe the battery had been disturbed and certainly not replaced.

 

[Sandancers]

I spoke to the technician a short time ago and he assured me the battery was ok. If it would start the engine it didnt matter what it read on the Multimeter. When I pointed out that it would disconnect the tracker if it went below a certain level, as it had done in the past, he advised me to ring the tracker company and ask them to disconnect it from their system!!!

I asked him point blank if he had exchanged the battery and he said he had, when I then asked which battery it was he said he thought it was the AGM Fiat, he had switched it like for like.

He said a reading of 12.4 was a full battery not under charge.

IF the battery had been removed to be changed and that is the battery which runs your tracker then surely you'd have got a warning from the tracker Company at the time ?

 

[Teasy2007]

We certainly thought it would, I even rang the tracker company to see if the tracker had lost power around the time he was changing the battery. It hadn’t.

My son said there was no evidence that the battery had been changed.

This morning the reading was 12 so we immediately put the camper on hook up.

It would seem that the battery is reading as good, but the drain is 0.79 - 1.1 instead of 0.07 which the technician told us was the normal drain.

There was nothing switched on on the camper at all, so it seems the question is what is draining the battery? And where do we go from here?

 

[autorouter]

There was nothing switched on on the camper at all, so it seems the question is what is draining the battery? And where do we go from here?

It's a case of working outwards from the battery, testing each branch of the wiring until you home in on the culprit. That clamp meter in the photo looks like a good tool for the job. (Kewtech KT203, available from Screwfix).

Some favourites are alternator diodes leaking, radio/media player not going into sleep mode when turned off, or the classic light left on in the garage/locker.

 

[autorouter]

This morning the reading was 12 so we immediately put the camper on hook up.

Did you check with the meter that the cab battery was actually charging? ie over 13.5V?

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[Teasy2007]

It's a case of working outwards from the battery, testing each branch of the wiring until you home in on the culprit. That clamp meter in the photo looks like a good tool for the job. (Kewtech KT203, available from Screwfix).

Some favourites are alternator diodes leaking, radio/media player not going into sleep mode when turned off, or the classic light left on in the garage/locker.

Given that the Camper is still under warranty: the dealer seems less than interested in sorting the problem: we don‘t know enough to do the investigation and we dont really want to spend a day travelling to the dealer and waiting for the Technician to tell us nothing is wrong, again, it seems the only/best option would be to keep an eye on the battery, cross our fingers and hope it doesn’t let us down.

I will email the service department with the photo and query the technician’s reading of 0.07.
I wont hold my breathe for a solution!!!

Thanks for your expertise and advice Autorouter, it is great that we can ask questions and receive great advice in return.

 

[Teasy2007]

Did you check with the meter that the cab battery was actually charging? ie over 13.5V?

That’s something we can do!

 

[Teasy2007]

Did you check with the meter that the cab battery was actually charging? ie over 13.5V?

We unplugged the Camper, and checked the multi meter, which read 13.1, after 5 hours on hookup. I dont know if that is good or bad! It dropped to 12.7 on the camper display after 10 minutes.

 

[autorouter]

We unplugged the Camper, and checked the multi meter, which read 13.1, after 5 hours on hookup. I dont know if that is good or bad! It dropped to 12.7 on the camper display after 10 minutes.

Looks OK to me.

A battery can never give out more than 13.6V on its own, so if you see a voltage of more than 13.6V, that means something is charging it.

Many mains chargers are 3-stage intelligent chargers.
Stage 1 is a gradual increase from about 13V to a maximum of about 14.4V.
Stage 2 is a constant 14.4V.
Stage 3 is a constant float voltage of about 13.4V.

Stages 1 and 2 can take several hours if the battery is really flat, or it can race through them in a minute or two if it's already fully charged. It should then stay at the float voltage indefinitely.

When you unplug the charger, the battery voltage gradually drops from the float voltage to the resting voltage, which can take up to an hour or so if there's no drain on the battery, or a few minutes if there's a small drain.

Your battery dropping from 13.1V to 12.7V in 10 minutes is about what I'd expect for a battery with a small drain. This chart is the 'resting' voltage for a standard flooded lead-acid battery like a starter battery. Other lead-acid types, like AGM or Gel, are slightly different.

 

[Vipar]

Put a mark on the battery in a non obvious place take a picture on your phone. Go back to the supplier and say you not satisfied with the exchanged battery would they swap it for another. They can’t say no as it is still new and must be under warranty. Then when they say that they has swapped it check for the mark and if it’s not there you have a new battery fitted. If the mark is there the produce your evidence.

I have been caught a couple of times, so I mark filters and anything that has to be changed. I have caught main dealers out on a couple of occasions last one cancelled the £200 bill when I threatened to take it further.

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[Googlebot]

Demand a new battery and just keep banging on at them.

If you have a drain and it’s under warranty then it’s their problem. The drain will knacker any battery you put on so needs sorting ASAP.

You can pull each fuse out with the meter connected to see which circuit is the problem.

 

[Teasy2007]

Demand a new battery and just keep banging on at them.

If you have a drain and it’s under warranty then it’s their problem. The drain will knacker any battery you put on so needs sorting ASAP.

You can pull each fuse out with the meter connected to see which circuit is the problem.

Is there any way on knowing how much drain is to be expected? We have never had this problem with any other motorhome and cant understand why a Carthago Malibu 640 should have ‘something’ which is causing the drain.

We have always had Alarms fitted on previous Motorhomers, but decided to go for a tracker because we were sick of alarms going off, nobody taking any notice etc. The tracker has been checked by the tracker technician, who, apart from reinstalling in another position, said the tracker should drain a minimal amount and only really wakes up when the engine is started or the battery is disconnected.

We have now checked the battery on a number of occasions and from fully charged 13.4 on the display to 12.2 takes about 3 days, depending on the amount of sunshine.

 

[autorouter]

We have never had this problem with any other motorhome and cant understand why a Carthago Malibu 640 should have ‘something’ which is causing the drain.

It's because there is a fault somewhere. A drain of 0.5 amps will drain 0.5 x 24 = 12 amp-hours in a 24 hour period. In 3 days it will drain 36 amp-hours, which will take a 100 amp-hour battery down to 64% charge level. That's about what you are seeing.

You have seen with your own eyes a drain of 0.79 amps, in the photo in post #36. I would be hoping for a drain of 10 times less, so it would last two or three weeks at least without hookup.

Once the fault is fixed, a solar panel should be able to compensate for a drain of 0.1 amps.

 

[Teasy2007]

We have just decided to put the cover back on the battery and I asked if the inline fuse should actually have a fuse in it?

 

[Teasy2007]

On the top of the battery are 8 numbers and a letter, can anyone tell me what date these represent, Ive tried to find the code but have cant find anything.

The etched numbers look like 234T and directly underneath A454.

The battery is on a 2019 Fiat Ducato.

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[Googlebot]

Not sure of the numbers on the battery I am afraid. Ref the fuse, I can’t see why someone would fit it and it would have no fuse?

Can you trace where the cable goes?

You really do need to sort it, the problem won’t go away and will just eat your batteries at great cost. They aren’t cheap.

 

[joka250]

We have just decided to put the cover back on the battery and I asked if the inline fuse should actually have a fuse in it?

That fuse holder and the wiring to it do not look original to me. You need a decent auto electrician to check the whole system. I assume warranty won't pay for that but if it solves the problem you'll have peace of mind.

 

[Teasy2007]

I think Autorouter may have the right idea with it being for the solar panel. The cab battery was being charged from the solar panel until we brought it home last Tuesday. We just thought that the recent bad weather wasn’t enough to boost it until we saw the empty fuse holder!!

 

[Googlebot]

I think Autorouter may have the right idea with it being for the solar panel. The cab battery was being charged from the solar panel until we brought it home last Tuesday. We just thought that the recent bad weather wasn’t enough to boost it until we saw the empty fuse holder!!

It is entirely possible that the technician has removed the fuse to check for drain and then forgot to put it back.

 

[Teasy2007]

It is entirely possible that the technician has removed the fuse to check for drain and then forgot to put it back.

I emailed them yesterday, the receptionist replied within a few minutes but I have heard nothing from them since. One thing for sure we are not going back to the Dealer until it needs its first habitation check in May.

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[Teasy2007]

That fuse holder and the wiring to it do not look original to me. You need a decent auto electrician to check the whole system. I assume warranty won't pay for that but if it solves the problem you'll have peace of mind.

We had the solar panel, charging point for Mike’s oxygen machine and inverter all fitted when we bought the Malibu in May, so everything is as it was when we took delivery.

We dont have enough knowledge to do this type of job and we only asked our son to check the battery because we did not have the equipment or knowhow.