Knaus Sun TI electrical problem HELP PLEASE ☹️

[Spinksy50]

Hi all,
We’ve had our 2005 Knaus Sun Ti on a Renault Master base for a week. We took it away for the night to test, everything worked well off grid. However, on returning from the pub, the test button for the vehicle battery showed it only half-charged. The leisure battery remained fully charged. Curious.
The vehicle battery is now completely flat, having sat on the drive for 2 days. There is no internal power, despite the leisure batteries showing full charge.
I’ve checked Trip switches and Isolator switch, all fine. There is power to the panel, but nothing 12v.
Two new leisure batteries fitted just before we picked up... could it be wired to draw from vehicle battery by mistake???
We have it booked in for the dealer to look at, but it’s a long way and wondered if anyone had any ideas that might be an easy fix?
We’re booked to go away at Easter
Thanks for reading!
Lou:anyone:

 

[Canalsman]

There is usually a switch that allows the habitation 12 volt systems to be connected to either the leisure battery or the starter battery.

Make sure you have not selected the starter battery in error.

If the starter battery is faulty it may not be holding a charge, or it has been flattened due to incorrect selection.

 

[Spinksy50]

There is usually a switch that allows the habitation 12 volt systems to be connected to either the leisure battery or the starter battery.

Make sure you have not selected the starter battery in error.

If the starter battery is faulty it may not be holding a charge, or it has been flattened due to incorrect selection.

I’ve read that but couldn’t find anything obviously like a switch. Any idea where it would be and what it would look like please?

 

[maingate]

What charging system do you have. It could be Electroblock or Reich?

The first place I would look is the charging unit, check the fuses.

Second place is next to the engine battery. There could be some fuses near it, one of them is a small 2 amp fuse which is for the charging circuit. It could have blown.

 

[r4dent]

Do you have anything (usually at or above eye level) that could be a control box.

If so can we have photos please.

Check your documentation to see if you have a manual for any thing that included the words control or distribution or anything electrical.

Check your main van manual for a section called "12v electrics".

I am of the school that thinks there is a switch somewhere.

Is there an owners club for our van. These are great sources of answers.

 

[Spinksy50]

Do you have anything (usually at or above eye level) that could be a control box.

If so can we have photos please.

Check your documentation to see if you have a manual for any thing that included the words control or distribution or anything electrical.

Check your main van manual for a section called "12v electrics".

I am of the school that thinks there is a switch somewhere.

Is there an owners club for our van. These are great sources of answers.

Hi,
Thanks for your help all.
Update.. we left the fridge on 12v setting by accident when we parked up. Could this have drained the vehicle battery?although doesn’t explain why we now have no 12v power despite apparently fully charged leisure batteries...? Pic of control panel attached.

 

[Spinksy50]

If the engine battery is completely flat, whatever is powered from it will have stopped working. All the habitation stuff should run off the habitation battery. So they should all still work. If anything doesn't, that's the culprit!
The car radio in the dash probably runs off the engine battery. You haven't left that on, have you?
It may just be that the engine battery had died. Even more likely now: best get it charged and checked before messing with anything else.

Absolutely nothing now works, lights/tv/pump... even when I’ve hooked up to 240v! It’s a mystery for the dealer I guess.

 

[r4dent]

Update.. we left the fridge on 12v setting by accident when we parked up. Could this have drained the vehicle battery?although doesn’t explain why we now have no 12v power despite apparently fully charged leisure batteries...? Pic of control panel attached.

Fridge running on 12v would flatten a battery in about 30 mins. However, Fridges 12v normally only connects to car battery and is usually connected only when ignition is on and often only when engine is running.

Thanks for photo, I don't know that particular panel but hopefully someone else might. Do you know the make or Model. Your symptoms sound like you are running all 12v off cab battery and that your charger is only connected to hab battery. Any other panels visible?

To get home you could consider swapping hab/cab batteries or jump starting from hab batery.

 

[Spinksy50]

Fridge running on 12v would flatten a battery in about 30 mins. However, Fridges 12v normally only connects to car battery and is usually connected only when ignition is on and often only when engine is running.

Thanks for photo, I don't know that particular panel but hopefully someone else might. Do you know the make or Model. Your symptoms sound like you are running all 12v off cab battery and that your charger is only connected to hab battery. Any other panels visible?

To get home you could consider swapping hab/cab batteries or jump starting from hab batery.

Bless you, thanks. Luckily it went flat on our driveway, so could be worse. I thought the same as you, somehow things are wired to run off vehicle battery by mistake. The dealer has been fab on the phone, so fingers crossed

 

[MarkJ]

Do let us know what the problem turns out to be....

 

[Mick H]

Knaus Sun TI

On a standard Knaus Sun Ti 650MF, there is NO switch, to select between starter/habitation batteries.
The charging/distribution circuits, are controlled by a Calira system. Unfortunately, there have been numerous issues, with this, for many Sun Ti owners.

Based on what you have said, I suspect, that the Calira, might not be charging, and, if this has been going on, for some time, there has been a steady deterioration, of both batteries, because they have only been receiving a charge, whilst driving. Also, depending on the batteries age, they might well be past their best.

If it is the Calira, then replacements are quite expensive, but they can be repaired, but, again, not cheap!

A number of owners, are now on their 3rd Calira. In my opinion, they are NOT robust enough, although a well known expert, disagrees, and blames the owners, for causing their failure.
Instead of renewing/repairing, a Calira, I would recommend replacing it, with a more robust charging system, but retaining the Calira control system, so that the "Bordcontrol" panel, would still work. I did this, myself, after 2 Calira failures, and everything has worked ok, for the last 8 years.

 

[Mick H]

The 240v hookup will probably only charge the hab battery, so if the hab power is coming from the engine battery, that won't help.
As you say, it really isn't your problem. The dealer needs to fix it.

With the Knaus Sun Ti. The Calira, automatically, controls all the charging regimes, for both batteries,
i.e. When on hookup, or from the Renault Master alternator.