Leisure Battery gauge stuck at 100%

[far.landscape]

Hi, this forum has already been very helpful - hoping someone may already know this…

The battery gauge on our Grand California (the one on the panel stuck outside the bathroom) is constantly stuck at 100%, permanently showing 0 amp draw regardless of actual draw and 0hrs and minutes remaining, and constantly showing a “charging” status if on hook up (ie it still shows “charging” even having been on hook up for >2 days).

The battery must be charging and holding a charge to some extent, as we can “off grid” for a night and still have some power the following morning (albeit with an apparent drop of voltage eg the water pump seems less strong), but this means we never have any idea how much charge is actually in the battery or what kind of condition it’s in.

Does anyone know how to reset this or what may be the cause or the solution? Turning the red “master” switch off in the electrics locker for >10 mins did not solve, albeit I tried this during the day so possibly solar (which we have as an option) was providing some voltage??

I’m guessing pulling one of the fuses may do it, although I’m reluctant to do anything too “risky” as we’re in the middle of a trip and as it’s working-ish I don’t want to risk making anything worse. I suspect the battery may not be in great condition (we purchased second hand, and the gauge has been reading like this since we got it) but it would be more than useful to at least know what the charge status is. I don’t have a multimeter to hand to directly check but am going to try to pick one up while on this trip (quite remote at the moment).

(note, I have already searched and read in full every battery related post for the GC600 & GC680 on this forum, and didn’t find anything related to this).

 

[Bart7974]

Hi,

could be a software failure of the central processing unit (VW name :customer-specific functional control unit ,CFCU)) you can reset this CFCU.

Try the following :
- Disconnect the blue connector , wait one minute, and then reconnect the blue connector in front of the passenger foot area installed on the right of the dash panel behind the glove compartment.

Bart

 

[Bart7974]

disconnecting of the blue connector is a little bit tricky , important to wait 1 to 2 minutes.

I am still waiting and preparing for my GC600, have this information from German GC users of the caliboard.de

 

[far.landscape]

Hi Bart, thank you for this. I’d done that already as part of trying to resolve a problem with the water pump (turned out to be water in the tap, shorting the micro switch).
This battery gauge issue has been the same before and after doing that, so unfortunately that can’t be it.

 

[far.landscape]

This is what my battery gauge has looked like since I got the GC600. Percentage, Voltage, current and time always looks like that (100%, 12.7v, 0 A, 0 h 0 min). If on hook up, then the green gauge shows “charging”. (But still at 100%)

For avoidance of doubt, the display is not frozen. Other than this, all menu options, temperature readout, heating control, time etc, work as expected.

 

[yossarian]

Can you take a photo of your leisure battery connections?

 

[yossarian]

My thought process is that if vw is using an IBS to measure the battery the IBS can be reset separately. Check the end of this thread for what it should look like and how to reset it. https://vwcaliforniaclub.com/thread...ontrol-panel-to-“reset”-battery-status.41312/

 

[far.landscape]

Can you take a photo of your leisure battery connections?

My thought process is that if vw is using an IBS to measure the battery the IBS can be reset separately. Check the end of this thread for what it should look like and how to reset it. https://vwcaliforniaclub.com/threads/hard-reset-of-6-1-control-panel-to-“reset”-battery-status.41312/

Thank you for this thought. Will have a look and post if / once found.

 

[far.landscape]

Bit of additional info after paying attention to this since previous off grid trips…

After 24hrs off grid, fridge running (power setting 3, night mode overnight), sink use twice, 2 quick showers, but conservative use otherwise, I notice:

Fridge is now “off” (still cold, but compressor is not coming on, and it’s flashing a 5 light sequence when opening the door), and the water pump is only actuating for a few seconds before triggering off. Also, lights in bathroom are slightly dimmer than usual.

I’m guessing this means voltage is low, although obviously with this sensor reading issue and no multimeter on hand I don’t know for sure. I’m also guessing that running out after that use means my battery is not “dead”, but not in great condition either.

Heading to Stornaway today to grab a multimeter…

 

[Bart7974]

My thought process is that if vw is using an IBS to measure the battery the IBS can be reset separately. Check the end of this thread for what it should look like and how to reset it. https://vwcaliforniaclub.com/threads/hard-reset-of-6-1-control-panel-to-“reset”-battery-status.41312/

Hi ,
as far as I could see is this a possible solution for a T6.1 . "far.landscape" has a Grand California and this has a different battery management.

A battery management reset in a GC is possible with the "blue connector " disconnection.
But with this method the cut off time of 1 to 2 minutes very important not only a few seconds.

Members told that a "some seconds cut off " did not reset the system. A longer cut off time did do the job.

Bart

 

[Bart7974]

View attachment 82611

This is what my battery gauge has looked like since I got the GC600. Percentage, Voltage, current and time always looks like that (100%, 12.7v, 0 A, 0 h 0 min). If on hook up, then the green gauge shows “charging”. (But still at 100%)

For avoidance of doubt, the display is not frozen. Other than this, all menu options, temperature readout, heating control, time etc, work as expected.

other possible solutions:

- you wrote its a second hand GC600, maybe it needs a software update--> VW dealer
- hardware problem of the CFCU--> VW dealer has to replace it

try to find a VW dealer
Bart

 

[far.landscape]

Hi ,
as far as I could see is this a possible solution for a T6.1 . "far.landscape" has a Grand California and this has a different battery management.

A battery management reset in a GC is possible with the "blue connector " disconnection.
But with this method the cut off time of 1 to 2 minutes very important not only a few seconds.

Members told that a "some seconds cut off " did not reset the system. A longer cut off time did do the job.

Bart

Correct it is a Grand California. I have disconnected the blue connector for > 2 mins and it did not resolve the issue unfortunately.

 

[far.landscape]

other possible solutions:

- you wrote its a second hand GC600, maybe it needs a software update--> VW dealer
- hardware problem of the CFCU--> VW dealer has to replace it

try to find a VW dealer
Bart

…not terribly likely where I am at the moment…

 

[Bart7974]

…not terribly likely where I am at the moment…

I just looked "Stornoway" up on the map , wow very nice area , that is one of our future trips with our GC600.
The nearest VW dealer is in Inverness on the "mainland "

 

[yossarian]

Thank you for this thought. Will have a look and post if / once found.

The battery in question is probably the one in under the bonnet.

 

[far.landscape]

The battery in question is probably the one in under the bonnet.

Yes, got it. See photos.

Unfortunately, I disconnected the plug attached to the negative for > 2mins and readout on the panel is the same.

New symptom, having run engine charging (pressing the engine battery button on the dash) the fridge was still not functioning. I then switched off the red master switch and disconnected that blue plug for > 5 minutes, on restart, the fridge worked but then on checking heating I got W 302 H on the truma (which means voltage < 10v) and the fridge failed and would not restart. I then repeated the switch off sequence and the fridge restarted for a few minutes, and this time I get a “low voltage” warning on the solar controller!! I’m running engine charging again but am suspecting that due to this battery monitoring problem the battery has been “killed”.

All the while the display on the bathroom is reading 100% (the display does switch off entirely when the red switch is switched off).

I’ve checked all cables under the left side seat and left side dash (right hand drive vehicle) and nothing is loose.

I’m running engine charging again but am suspecting that due to this battery monitoring problem the battery has been “killed”.

 

[far.landscape]

Photos for above post

 

[far.landscape]

This is the battery I have under the bonnet, which I believe to be the leisure battery according to reading previous posts.
After 1.5hrs of engine Charging while driving and now picking up a multimeter, It reads 11.8v while the red switch is off, and dips to 10.02, when the switch is on and the fridge is on.

Chap in the garage here has questioned if this is the correct battery for a campervan.

Anyone know if this is the standard and what sort of dip voltage I should expect when the fridge is on?

I’m guessing it’s cutting out when it dips below 10a…

 

[yossarian]

View attachment 82632
This is the battery I have under the bonnet, which I believe to be the leisure battery according to reading previous posts.
After 1.5hrs of engine Charging while driving and now picking up a multimeter, It reads 11.8v while the red switch is off, and dips to 10.02, when the switch is on and the fridge is on.

Chap in the garage here has questioned if this is the correct battery for a campervan.

Anyone know if this is the standard and what sort of dip voltage I should expect when the fridge is on?

I’m guessing it’s cutting out when it dips below 10a…

Assuming your fridge draws 7A or so while running a 1.8V drop suggests a resistance of about 0.25 Ohms. Very high and if it's the battery internal resistance and not a damaged or loose cable then suggests the battery is done. Check by putting the multimeter on measuring the voltage on the battery terminals while running the fridge. A new battery should have internal resistance of less than 0.003 Ohms.

I'm pretty sure I've seen GC OEM equipment list a 92AH AGM battery as standard. That one looks correct to me.

Anyone know if this is the standard and what sort of dip voltage I should expect when the fridge is on?

Based on 7A current expected voltage drop at the battery terminals is 0.02V.

Edits: clarify measurements / answer V drop question.

 

[Bart7974]

View attachment 82632
This is the battery I have under the bonnet, which I believe to be the leisure battery according to reading previous posts.
After 1.5hrs of engine Charging while driving and now picking up a multimeter, It reads 11.8v while the red switch is off, and dips to 10.02, when the switch is on and the fridge is on.

Chap in the garage here has questioned if this is the correct battery for a campervan.

Anyone know if this is the standard and what sort of dip voltage I should expect when the fridge is on?

I’m guessing it’s cutting out when it dips below 10a…

Yes I also can confirm that this is the right battery.

But your battery seems to be gone . But what is the cause ?

Because you have a “stuck gauge at 100%” and a very low battery voltage maybe the IBS, see post #7 yossarian, or the control unit CFCU is faulty.


Bart
Bart

 

[far.landscape]

Yes I also can confirm that this is the right battery.

But your battery seems to be gone . But what is the cause ?

Because you have a “stuck gauge at 100%” and a very low battery voltage maybe the IBS, see post #7 yossarian, or the control unit CFCU is faulty.


Bart
Bart

Yes I tried disconnecting the IBS but unfortunately it did not resolve.

 

[far.landscape]

Yes I also can confirm that this is the right battery.

But your battery seems to be gone . But what is the cause ?

Because you have a “stuck gauge at 100%” and a very low battery voltage maybe the IBS, see post #7 yossarian, or the control unit CFCU is faulty.


Bart
Bart

Thanks for confirming the battery btw.

 

[far.landscape]

Assuming your fridge draws 7A or so while running a 1.8V drop suggests a resistance of about 0.25 Ohms. Very high and if it's the battery internal resistance and not a damaged or loose cable then suggests the battery is done. Check by putting the multimeter on measuring the voltage on the battery terminals while running the fridge. A new battery should have internal resistance of less than 0.003 Ohms.

I'm pretty sure I've seen GC OEM equipment list a 92AH AGM battery as standard. That one looks correct to me.



Based on 7A current expected voltage drop at the battery terminals is 0.02V.

Edits: clarify measurements / answer V drop question.

Thank you for that explanation, and yes, the voltage is dropping 1.8v while the fridge is running, so confirms a “dead” battery.

two problems now…
1: getting hold of a new one with the same specs,
2: the original problem, ie why the van voltage sensor isn’t working (which is either the cause or a symptom of the issue), ie how to stop the same thing just happening again even if I do find a new one.

I’ve managed to find a friendly hookup for the afternoon and have been watching the voltages. It will “take a charge”, in the sense that it’s gradually increasing while on hookup (currently at 13.5v), but as soon as off hookup it drops at the rate of 0.1v per minute. Again confirming a duff battery, which I guess I already knew…

 

[Bart7974]

just to verify you measure on the "right" battery:
Your battery picture looks as if it is the motor battery, I can not see the high amp fuses.

You are now connected to the grid and charging, what does your display show ? still 100% , frozen ?

 

[Bart7974]

just to verify you measure on the "right" battery:
Your battery picture looks as if it is the motor battery, I can not see the high amp fuses.

You are now connected to the grid and charging, what does your display show ? still 100% , frozen ?
View attachment 82650

and here the 2 batteries: