2nd battery error message

[MackM]

Hi, I have a new California T6.1 and have managed to get away a few times including a quick trip to France. An error message “Second battery low” has appeared. I have 2 solar panels which have been working fine from Roger and was driven nearly 400 miles yesterday but the message still persists. I have plug into the mains this morning but no change.

Firstly I am not sure which is the second battery I.e. the one in the cupboard or under the seat? Secondly, I Was hoping there might be some advice on anything I can look at like a fuse? I have booked the van in later in the month but would be good to sort as off to the New Forest this weekend. Many thanks

 

[Nick Stubbs]

I you have a volt meter/multi meter check the voltage on both battery's whichever is the lowest has the problem, then check the fuses on the terminal posts. If both have the same voltage maybe an issue with the display or monitoring circuitry.

 

[Loz]

The questions I would ask myself, did they mean second battery as in individually (does it understand 3rd battery) of just the leisure batteries as a whole and therefore the leisure batteries are not being charged.

edit: I have the 6.1 circuit diagrams so I might take a look and see if it monitors the batteries separately.
My hunch is;
Your solar is connected to the rear battery and its at 100% but the cube fuse has blown and the under-seat battery is low.

 

[Loz]

Update
3 battery monitors are indeed installed so the message refers to the second battery under the passenger seat.
So I would suggest you check the main block fuse on the 3rd battery in rear wardrobe.

I would also check the battery voltages when the hookup is plugged in to make sure it is charging both batteries.
You may have more than 1 fault, but tackle one at a time. so as not to get confused

 

[MackM]

Update
3 battery monitors are indeed installed so the message refers to the second battery under the passenger seat.
So I would suggest you check the main block fuse on the 3rd battery in rear wardrobe.

I would also check the battery voltages when the hookup is plugged in to make sure it is charging both batteries.
You may have more than 1 fault, but tackle one at a time. so as not to get confused

Thanks - I will have a look

 

[andyinluton]

Loz

Any idea how the separate battery monitors work? My initial thoughts were that as the two leisure batteries are permanently connected to each other, they would be seen as just one battery. Any chance of a look at the 6.1 charging diagram?

Actually was half tempted to suggest that actually its his phone battery thats the problem looking at the top left of the screenshot!

 

[MackM]

I you have a volt meter/multi meter check the voltage on both battery's whichever is the lowest has the problem, then check the fuses on the terminal posts. If both have the same voltage maybe an issue with the display or monitoring circuitry.

What is a terminal post? I will then have a look. Thanks

 

[MackM]

Loz

Any idea how the separate battery monitors work? My initial thoughts were that as the two leisure batteries are permanently connected to each other, they would be seen as just one battery. Any chance of a look at the 6.1 charging diagram?

Actually was half tempted to suggest that actually its his phone battery thats the problem looking at the top left of the screenshot!

Still comes up with the same fault even without the phone connected but a good thought

 

[Nick Stubbs]

What is a terminal post? I will then have a look. Thanks

The big lug on top of the battery, the large fuses are connected to it pressuming they are the same as the T6

 

[MackM]

main block fuse on the 3rd battery in rear wardrobe

Is this in the battery compartment under the wardrobe?

 

[Loz]

Is this in the battery compartment under the wardrobe?

Yes

 

[Loz]

Loz

Any idea how the separate battery monitors work? My initial thoughts were that as the two leisure batteries are permanently connected to each other, they would be seen as just one battery. Any chance of a look at the 6.1 charging diagram?

Actually was half tempted to suggest that actually its his phone battery thats the problem looking at the top left of the screenshot!

Yes, a major upgrade to how they were previously connected. Each battery now has its own monitor like the starter battery has and each one is on the can bus and feeds to a new special vehicles module which is also connected to the new display unit.

 

[altvic]

Is this in the battery compartment under the wardrobe?

yes

 

[andyinluton]

Loz

When the cube fuse blows what gets separated from what? On the T5.1 maybe incorrectly I assumed it separated the live connection between the front & rear batteries. I also assumed - dont know why, that both the engine and the battery charger supplied the front battery & the fused link relayed that charge to the rear one. Leaving you in the event of the fuse blowing effectively with just the front battery working.

If that is/was the case & the arrangement is still similar, blowing the fuse wouldn't stop the front battery( battery 2) being charged from the alternator or the charger & following a lengthy drive battery 2 should be charged?

 

[Loz]

In the case of ours, the cube fuse sits on rear(3rd) battery so yes, as you say it becomes isolated from everything else, but Roger used to connect his solar charger to the rear battery so there could be a case where his solar is quite happily charging the rear battery in isolation.
Now with the 6.1 having proper battery monitors(and not just a shunt that requires the earth from the 3rd battery to be also run to the shunt) it can tell you which battery is flat.

However, in the current case of the OP, to have a flat second battery and a full 3rd battery there have to be other things going on as there are 2 other systems charging the 2nd battery; 1. the alternator through the split charge relay and 2. the mains charger.

I am currently thinking that the 2nd battery monitor is simply not correctly assuming the charge state, especially if the block fuse is okay then the 2 batteries are effectively in parallel.

The other thing it could be is a duff second battery. See later update

 

[MackM]

This what the Victron app and camper panel tells me. it has over 60 hours of charge but there is a red ! On the battery. So it could be just a faulty reading?

 

[andyinluton]

How intelligent is the split charge relay in the 6.1 & indeed the charger ? do they use the information from the battery monitors?

MackM does that new control panel show battery voltage? if so what voltage?

 

[Loz]

How intelligent is the split charge relay in the 6.1 & indeed the charger ? do they use the information from the battery monitors?

Unfortunately, despite all the new stuff they have stuck with the simple relay we have

 

[andyinluton]

Id be tempted to pull the big fuse & see what voltage is shown then.

 

[Loz]

That display is not helpful and just wrong IMO it says 13V but also says less than 60AH, as the new monitor is based on a calculation of charge in and charge out I just don't think it has had enough cycles to correctly calculate the capacity.

Also, where on the battery is the Solar connected? is it on the correct side of the battery monitor?
It may be simply that the solar is charging the batteries but the battery monitor is not seeing it as the solar is directly connected to the battery posts?

 

[MackM]

It may be simply that the solar is charging the batteries but the battery monitor is not seeing it as the solar is directly connected to the battery posts?

That maybe true but 400 miles of driving yesterday and it’s been plugged into the mains all morning so that should register the charge?

 

[MackM]

MackM does that new control panel show battery voltage?

Sadly not. Only what is shown...

 

[Loz]

That maybe true but 400 miles of driving yesterday and it’s been plugged into the mains all morning so that should register the charge?

Then assuming all charging systems are working, the only conclusion is that the calculation is incorrect and it should sort itself out after a few discharges, which may take a while if its always being kept fully charged

 

[kurienp]

To be doubly sure, I would get a multimeter and measure the voltage in each battery.

 

[MackM]

Then assuming all charging systems are working, the only conclusion is that the calculation is incorrect and it should sort itself out after a few discharges, which may take a while if its always being kept fully charged

I would suspect there has been very little discharging going on with all the sun we have had