Burstner 2016 - Issue with Inbuilt battery monitor over hab door - Any Thoughts

[Miss Trinity]

I have a Burstner Nexxo T660 with a monitoring panel over the Habitation door which has a indicator needle that is not returning to zero after taking a battery reading. It's worked fine till now, but just checked the batteries and both habitation were showing very low readings and the cab battery was dead. A bit surprised as had it on EHU throughout winter at various times during the past month. But we have had severe frosts of -5'C for a number of nights so I suspect the cab battery is knackered as over 5 years old. Is this the likely cause for the monitoring needle not returning to zero. And will a new cab battery fix this problem. I would really appreciate your help as its my only transport and I dare not risk getting stuck away from home. Many thanks Trinity.

 

[Stanbrook]

Sorry to hear about your poorly motorhome, is this the same control panel?

Did you follow the instructions in the Burstner manual about winter lay up?

Have you tried charging the batteries on hookup for a couple if days and then testing them?

Does the vehicle start? Does the electric step work?

Are you doing the repairs yourself? Dealer to fit new batteries? Good luck

 

[autorouter]

Most batteries fail by gradually losing storage capacity, until one day they won't start the engine. Winter is the worst time. Battery capacity reduces at low temperature, and the engine is harder to turn when the oil is cold and thick. So the chances are, if the battery is 5 years old, it's on its way out.

However a flat battery can also be a result of other faults, so it's important to check for these, so you don't end up in a few weeks with a new battery that's gone flat again.

You can get a lot of information by just looking at the voltages. You need to know about resting voltage, charging voltage and float voltage.

If a battery is not being charged and has no loads draining it, the voltage will settle to its resting voltage. It might take a few hours to do this, after a long drive for example. Typical resting voltage is 12.0V (as empty as you would normally go) to 12.8V (100% full).

If the battery is being actively charged, the charger will push the voltage up to the charging voltage, between 14.4 and 14.8V.

When the battery is full, the charger drops the voltage down to the float voltage. This keeps the battery charged without overcharging it. Typical float voltage is 13.4 to 13.8V.

When you plug in the EHU, the voltage should rise from resting voltage to charging voltage. If the battery is very flat, it might take some time to reach the full charging voltage, maybe a few hours. But it should gradually rise. When it's fully charged, it will drop down to the float voltage.

Similarly when you start the engine, the voltage should rise from resting voltage to charging voltage. For both batteries.

With all this information, you can see if the EHU is charging each of the batteries, and also if the alternator is charging the batteries when the engine is running.

 

[autorouter]

Is this the likely cause for the monitoring needle not returning to zero

The best way to check the panel meter is to use a multimeter on the battery terminals, and compare the panel meter readings. A multimeter is a useful tool in a motorhome, and it's easy and safe to measure voltages with one.

Any cheap meter will measure the battery voltages. You can get one for a tenner or less, from Screwfix, B&Q etc.

Plug the black lead into the 'COM' socket, and the red lead into the socket with 'V' in its label.

Turn on the meter, and set the range to 20V (DC Volts). Push the black probe onto the battery negative terminal, pressing hard to cut through any oxidation layer down to the metal. Push the red probe onto the battery positive terminal, again pressing hard. The display should read between 10 and 15 volts.

If you get them the opposite way round, nothing bad happens, but a minus sign appears in front of the voltage reading.

Now you can check the panel meter reading against your multimeter reading, to see if the panel meter is working OK. With a bit of luck, that non-zero offset will just be a bit of offset that you can take into account when reading the panel meter. If it's all over the place, then at least you know.

These panel meters are generally robust and reliable, but they involve magnets, springs, coils and pivots, so plenty to go wrong.

 

[SmithsInFrance]

We've got a burstner with the same panel and the needle on the meter regularly sticks at zero when we check (even though batteries are charged). Mentioned it once when it went for a service, but don't think they did anything.

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[Miss Trinity]

That's most helpful and thorough thank you. I am now well on with checking the cab & hab batteries in their various states, isolated, solar, EHU and alternator charging and so far everything is pointing to a faulty gauge on the panel which you correctly identified. So if all goes well by tonight I am hoping it's just that which is manageable till I get a chance to speak with my dealer as it should be covered. Sure been a tricky job as initially I was blindly trusting the gauge reading as I have over the past 3 years, so never considered the gauge was at fault. But that would be a real positive outcome in the current circumstances, especially with Lockdown still thwarting our chance to wander... I'll update when I know more, cheers Trinity =",'=

 

[Miss Trinity]

Seems that both cab & hab batteries are fully charged and there is no apparent discharge other than a negligible amount for tracker + alarm. The odd thing is the panel gauge only works on EHU & when engine is running, but not otherwise. I did rechecked all the EBL99 connectors and fuses but no joy. Any thing else I should know about or is this an actual fault i should be worried about as to be honest i have had enough of pulling things apart, at least for now. Still its drivable and safe to use. Thanks Funsters you've really helped me. Trinity =",'=

 

[SmithsInFrance]

The odd thing is the panel gauge only works on EHU & when engine is running, but not otherwise.

that's interesting - will check ours next time we take it out and see if that is the case for us as well. (not sure when that will be, but will report back eventually)

 

[Miss Trinity]

Hokky dokky, good luck