Different readings and fluctuating voltage shown on Control Panel

[Mr B]

Hi

Can anyone advise me on this issue:

- Whilst away on holiday I noticed some strange things happening with the battery voltage shown on my solar display

- It seemed to fluctuate up and down and never fully charged upto 14.4v even when driving (it used to always show 14.4v after sitting in the Sun or being driven with Lighs on for a journey) - now max it charges to is 13.5v after sitting in the Sun for a whole day

- Just got in the van and it is showing 12.5v on the Camper Control Panel even after being sat in the Sun for a couple of days

- It's doing loads of weird stuff now and I never had an issue for the last couple of years that I've had the solar installed.

- Both the solar control panel and the camper control panel would always show the same voltage in the batteries when driving or if I started the engine briefly when camping, now they show different values all the time and the Voltage fluctuates wildly

The photos show both control panels captured at the same time and the difference in the displays. The first two are with the engine on and captured at same time - the second two show the engine off and captured at the same time.





Are my batteries finished? Or is it something else? How do I troubleshoot this?

Thanks if you can help!

 

[WelshGas]

Hi

Can anyone advise me on this issue:

- Whilst away on holiday I noticed some strange things happening with the battery voltage shown on my solar display

- It seemed to fluctuate up and down and never fully charged upto 14.4v even when driving (it used to always show 14.4v after sitting in the Sun or being driven with Lighs on for a journey) - now max it charges to is 13.5v after sitting in the Sun for a whole day

- Just got in the van and it is showing 12.5v on the Camper Control Panel even after being sat in the Sun for a couple of days

- It's doing loads of weird stuff now and I never had an issue for the last couple of years that I've had the solar installed.

- Both the solar control panel and the camper control panel would always show the same voltage in the batteries when driving or if I started the engine briefly when camping, now they show different values all the time and the Voltage fluctuates wildly

The photos show both control panels captured at the same time and the difference in the displays. The first two are with the engine on and captured at same time - the second two show the engine off and captured at the same time.

View attachment 114612 View attachment 114613

View attachment 114614 View attachment 114615

Are my batteries finished? Or is it something else? How do I troubleshoot this?

Thanks if you can help!

1. You need to check the voltage on each leisure battery at least 30 minutes after engine Off or disconnection of mains hookup. NB Solar should be disconnected or measurements at night.
Using Multimeter, disconnect red wire on rear leisure battery, make sure it doesn't touch any metal, and measure voltage between disconnected red wire and black -tve pole on rear battery. ( This is the voltage of front Leisure battery ).
Then measure voltage between red +tve pole on rear battery and black -tve pole on rear battery. ( This is the voltage of the rear leisure battery ).
If you get 0 v when measuring rear battery then remove the cube fuse and try again as the cube fuse may have blown.

 

[WelshGas]

@Mr B
Normally the Solar panel is wired to the rear leisure battery. Depending on how the solar +tve connection is made, above or below the cube fuse, if the cube fuse fails the solar will only charge the rear battery, BUT all the power will be taken from the front battery to run the vehicle. You'll only have half your normal battery capacity.

 

[Mr B]

@Mr B
Normally the Solar panel is wired to the rear leisure battery. Depending on how the solar +tve connection is made, above or below the cube fuse, if the cube fuse fails the solar will only charge the rear battery, BUT all the power will be taken from the front battery to run the vehicle. You'll only have half your normal battery capacity.

I photographed the box fuse and it looked like it was fine - but I may be wrong.



I've got Solar Camper Solutions 100w panel and Epever MPPT.

I noticed in some threads that people were saying that you should connect the Solar negative to a ground point (rear battery clamp bolt) rather than the negative on the rear battery so I have tried that but it's made no difference.

It was always connected since install to the rear battery negative and it seemed to work fine for at least the last two years.

I will do the tests you recommended above when I can and report back. I'm currently at work so can't do it right now.

Thanks for your help.

 

[Mr B]

Also I should note - that when I look at the Camper Control Panel the little icon in the bottom right corner randomly starts flashing.

If I turn the Camper Control Panel on and off, it goes back to normal for a while. I also got an error 7001 on the panel which I cleared. I need to check if it's back again.

 

[WelshGas]

I photographed the box fuse and it looked like it was fine - but I may be wrong.

View attachment 114617

I've got Solar Camper Solutions 100w panel and Epever MPPT.

I noticed in some threads that people were saying that you should connect the Solar negative to a ground point (rear battery clamp bolt) rather than the negative on the rear battery so I have tried that but it's made no difference.

It was always connected since install to the rear battery negative and it seemed to work fine for at least the last two years.

I will do the tests you recommended above when I can and report back. I'm currently at work so can't do it right now.

Thanks for your help.

Only on the T6.1 do you need to connect the Solar -tve to a ground point rather than the battery -tve pole.

 

[Mr B]

Only on the T6.1 do you need to connect the Solar -tve to a ground point rather than the battery -tve pole.

Oh ok - I'll put that back then to the -tve pole.

 

[Mr B]

1. You need to check the voltage on each leisure battery at least 30 minutes after engine Off or disconnection of mains hookup. NB Solar should be disconnected or measurements at night.
Using Multimeter, disconnect red wire on rear leisure battery, make sure it doesn't touch any metal, and measure voltage between disconnected red wire and black -tve pole on rear battery. ( This is the voltage of front Leisure battery ).
Then measure voltage between red +tve pole on rear battery and black -tve pole on rear battery. ( This is the voltage of the rear leisure battery ).
If you get 0 v when measuring rear battery then remove the cube fuse and try again as the cube fuse may have blown.

Both measure 13v

Car has been off for hour but solar was still charging up until I disconnected the battery +


Should I wait for a bit longer now I've disconnected the solar?

 

[Mr B]

Camper control panel is reading 12.9v

 

[Mr B]

I don't know what else or how to test further for this problem.

The batteries essentially won't charge to 14.4v from the alternator or from solar and both readouts from the camper control panel and the solar control panel show different readings.

This problem only occurred after VW changed my air conditioning wiring (at great expense) as the previous wiring was apparently non-standard according to them and had frayed.

I can't prove they caused it as I don't have enough knowledge but I can't see what else it could be.

I suppose it could be due to the mppt controller being faulty but how would that affect the alternator charging.

I guess I'll have to pay for an auto electrician to diagnose further.

 

[WelshGas]

Camper control panel is reading 12.9v

Those readings all seem OK, and I presume the Cube fuse checked out OK.

You might have some variation in readings over the past few weeks with the high temperatures . The fridge might well have been working hard and Solar Panel output starts dropping off as ambient temperatures rise above 25c.

The batteries seem OK but the true test is if they hold a charge over time. Leaving them both disconnected, by also disconnecting the -tve lead on both batteries and measuring the voltage of both every 48hrs for a week or so. The voltages should be almost equal and drop very little, if at all, over a week.

 

[Mr B]

Thanks

I've ordered ctek 5 charger which says it can check for faulty batteries so I'll try that too.

 

[derek_j_buchanan]

Hi

Can anyone advise me on this issue:

- Whilst away on holiday I noticed some strange things happening with the battery voltage shown on my solar display

- It seemed to fluctuate up and down and never fully charged upto 14.4v even when driving (it used to always show 14.4v after sitting in the Sun or being driven with Lighs on for a journey) - now max it charges to is 13.5v after sitting in the Sun for a whole day

- Just got in the van and it is showing 12.5v on the Camper Control Panel even after being sat in the Sun for a couple of days

- It's doing loads of weird stuff now and I never had an issue for the last couple of years that I've had the solar installed.

- Both the solar control panel and the camper control panel would always show the same voltage in the batteries when driving or if I started the engine briefly when camping, now they show different values all the time and the Voltage fluctuates wildly

The photos show both control panels captured at the same time and the difference in the displays. The first two are with the engine on and captured at same time - the second two show the engine off and captured at the same time.

View attachment 114612 View attachment 114613

View attachment 114614 View attachment 114615

Are my batteries finished? Or is it something else? How do I troubleshoot this?

Thanks if you can help!

As per boats the alternator is designed to recharge batteries after starting and does not take account of the battery status when it does. That’s why it is almost impossible to recharge a battery unless you are on a really long journey. Plug in to the mains. In terms of solar it looks at the battery and charges it based on the battery hence can fully recharge. Best bet is connect to mains and properly charge

 

[Mr B]

As per boats the alternator is designed to recharge batteries after starting and does not take account of the battery status when it does. That’s why it is almost impossible to recharge a battery unless you are on a really long journey. Plug in to the mains. In terms of solar it looks at the battery and charges it based on the battery hence can fully recharge. Best bet is connect to mains and properly charge

Thanks, but the solar when parked and the alternator with lights on when driving would fully charge the battery to 14.4v.

This was the same for the last three years

Now the batteries will only charge to 13.5v Max, even when left in the sun for 4 days or driving (with the lights on, so no blue motion kicking in) over 600miles.

As soon as you turn on the control panel, even with the engine on the display will show 12.3v - 12.7v and then start fluctuating. The display also shows negative amps being taken from the battery when it should be charging so it makes no sense. There is no draw from the batteries when everything is off so something weird is going on.

There is a fault somewhere, either with one of two leisure batteries or with the split charge relay I think.

I spoke to a 'master tech' at VW today and he thinks that is the most probable cause if one of the batteries isn't faulty.

I'll test the batteries and re charge them with the ctek 5 then hopefully that will make it easier to diagnose either way.

 

[ThomasHJ]

14.4v is a reading I only ever get when my Cali has been on electrical hookup for a while (12h) and the batteries are not being used. When they have been fully charged and at rest for a while.The second I disconnect the batteries from EHU, the reading will drop down to about 13.3 - 13.5v. To me this is normal battery behaviour.

 

[Mr B]

14.4v is a reading I only ever get when my Cali has been on electrical hookup for a while (12h) and the batteries are not being used. When they have been fully charged and at rest for a while.The second I disconnect the batteries from EHU, the reading will drop down to about 13.3 - 13.5v. To me this is normal battery behaviour.

It's not.

If you see my display you would understand!

The master tech assumed that too until I showed him the control panel with the engine running.

 

[dspuk]

Thanks, but the solar when parked and the alternator with lights on when driving would fully charge the battery to 14.4v.

This was the same for the last three years

Now the batteries will only charge to 13.5v Max, even when left in the sun for 4 days or driving (with the lights on, so no blue motion kicking in) over 600miles.

As soon as you turn on the control panel, even with the engine on the display will show 12.3v - 12.7v and then start fluctuating. The display also shows negative amps being taken from the battery when it should be charging so it makes no sense. There is no draw from the batteries when everything is off so something weird is going on.

There is a fault somewhere, either with one of two leisure batteries or with the split charge relay I think.

I spoke to a 'master tech' at VW today and he thinks that is the most probable cause if one of the batteries isn't faulty.

I'll test the batteries and re charge them with the ctek 5 then hopefully that will make it easier to diagnose either way.

There is no fault. Everything you describe here is normal behaviour for batteries. The response from @ThomasHJ is right and the only thing I would add is with the alternator and engine on you would expect to see it “overcharge” on the control panel but no battery stays at 14.4V. Battery rest for a Cali will generally be anything around the 13 mark, depending on a load of factors. A lot of people get het up about the numbers for no real reason. The Cali knows best.

 

[Mr B]

There is no fault. Everything you describe here is normal behaviour for batteries. The response from @ThomasHJ is right and the only thing I would add is with the alternator and engine on you would expect to see it “overcharge” on the control panel but no battery stays at 14.4V. Battery rest for a Cali will generally be anything around the 13 mark, depending on a load of factors. A lot of people get het up about the numbers for no real reason. The Cali knows best.

Thanks. I'll let the master tech know!

If you have solar you will often see 14.4v as the batteries maintain fully charged state nearly all the time when you are not using the van if parked outside in the sun.

I know it doesn't stay at that, of course it will drop, but I can no longer charge the batteries to that state., even on a long drive (lights on) with the alternator pumping max amps into them (I feel like I'm repeating myself here).

Further, the batteries will drop to a fluctuating low voltage very quickly (minutes) even with no load.

Lol. Why would I post if there was no problem?

Have you seen the photos on my first post?

Completely different results on two battery monitoring systems which were always synced for three years.

Sorry, it's not normal as you say, and I'll post the outcome once the issue is resolved. Not much more I can say really.

I know there is a fault but thanks for your comment.

 

[dspuk]

Thanks. I'll let the master tech know!

If you have solar you will often see 14.4v as the batteries maintain fully charged state nearly all the time when you are not using the van if parked outside in the sun.

I know it doesn't stay at that, of course it will drop, but I can no longer charge the batteries to that state., even on a long drive (lights on) with the alternator pumping max amps into them (I feel like I'm repeating myself here).

Further, the batteries will drop to a fluctuating low voltage very quickly (minutes) even with no load.

Lol. Why would I post if there was no problem?

Have you seen the photos on my first post?

Completely different results on two battery monitoring systems which were always synced for three years.

Sorry, it's not normal as you say, and I'll post the outcome once the issue is resolved. Not much more I can say really.

I know there is a fault but thanks for your comment.

Ok. Good luck.

 

[yossarian]

Thanks. I'll let the master tech know!

If you have solar you will often see 14.4v as the batteries maintain fully charged state nearly all the time when you are not using the van if parked outside in the sun.

I know it doesn't stay at that, of course it will drop, but I can no longer charge the batteries to that state., even on a long drive (lights on) with the alternator pumping max amps into them (I feel like I'm repeating myself here).

Further, the batteries will drop to a fluctuating low voltage very quickly (minutes) even with no load.

Lol. Why would I post if there was no problem?

Have you seen the photos on my first post?

Completely different results on two battery monitoring systems which were always synced for three years.

Sorry, it's not normal as you say, and I'll post the outcome once the issue is resolved. Not much more I can say really.

I know there is a fault but thanks for your comment.

It's pretty hard to help you here based on the information provided. Also if you are having a 3rd party do some work there's very little that can be done here.

If you decide to come back here I'd suggest a series of readings taken with a voltmeter at various points in your electrical system at the same time and with a single operational charge source. Good places to take readings are on the terminals of the three batteries. Note the MPPT claimed output at the same time.

 

[ThomasHJ]

Thanks. I'll let the master tech know!

If you have solar you will often see 14.4v as the batteries maintain fully charged state nearly all the time when you are not using the van if parked outside in the sun.

I know it doesn't stay at that, of course it will drop, but I can no longer charge the batteries to that state., even on a long drive (lights on) with the alternator pumping max amps into them (I feel like I'm repeating myself here).

Further, the batteries will drop to a fluctuating low voltage very quickly (minutes) even with no load.

Lol. Why would I post if there was no problem?

Have you seen the photos on my first post?

Completely different results on two battery monitoring systems which were always synced for three years.

Sorry, it's not normal as you say, and I'll post the outcome once the issue is resolved. Not much more I can say really.

I know there is a fault but thanks for your comment.

I wouldn't dare saying there is no problem. I'm just saying that the readings you mentioned seem normal to me when comparing it to my batteries. The thing is, voltage-readings for batteries while under load are rather useless. From the info you have given so far it's hard to draw hard conclusions.

I just went out to my Cali to check the readings I have myself and noticed the voltage on the control panel and the solar app are almost the same. This is not always the case, but the battery right now is in rest (and in float) and has been for the last 15 hours.

Another thing you can check (if you have this option with your solar controllor) is the history of the voltage readings. I have the same solar as you do, but a different controllor. When I look at the history I can see that the max. my battery has been at (every single day for the last week) is 14.4v. It will not be like that all day but at least at some point during the day it will be at 14.4v. This is in line with your exeriences in the past. If you can check the history of your solar panel you can see if you battery has been around 14.4v each day or not. That should at least help conclude if something is indeed wrong. To have reached 14.4v you must have had quite some sun or driven the van though..

 

[dspuk]

I wouldn't dare saying there is no problem. I'm just saying that the readings you mentioned seem normal to me when comparing it to my batteries. The thing is, voltage-readings for batteries while under load are rather useless. From the info you have given so far it's hard to draw hard conclusions.

I just went out to my Cali to check the readings I have myself and noticed the voltage on the control panel and the solar app are almost the same. This is not always the case, but the battery right now is in rest (and in float) and has been for the last 15 hours.

Another thing you can check (if you have this option with your solar controllor) is the history of the voltage readings. I have the same solar as you do, but a different controllor. When I look at the history I can see that the max. my battery has been at (every single day for the last week) is 14.4v. It will not be like that all day but at least at some point during the day it will be at 14.4v. This is in line with your exeriences in the past. If you can check the history of your solar panel you can see if you battery has been around 14.4v each day or not. That should at least help conclude if something is indeed wrong. To have reached 14.4v you must have had quite some sun or driven the van though..

100%

 

[Mr B]

Small update:

- both batteries are keeping charge and are reading 12.8v after a week or so disconnected

- both batteries passed all the testing from the CTEK 5 charger

- I have bought one of these and a new cube fuse that I saw you had recommended on another post

Battery Clamp Terminal

- I checked the fuses under the battery (see photo) - all look fine



I'll put it all back together now and report back soon - assuming it wasn't a dodgy cube fuse issue then what is next?

Also - have a look at these images from the Solar Panel Display - there are no Leisure batteries connected and it is reporting 14.2v on the Leisure battery circuit? Is that just an anomaly as the starter battery connection is still wired from the solar?

 

[Mr B]

Also just looking at my fuses - why is there no connection on the 50a fuse? Is that normal - I looked HERE and it says it is :

50 A / 100 A

Positive connection 1 (30) in interior wiring harness Positive connection 2 (30) in interior wiring harness Positive connection 3 (30), in main wiring harness

 

[vbk1975]

Hi

Can anyone advise me on this issue:

- Whilst away on holiday I noticed some strange things happening with the battery voltage shown on my solar display

- It seemed to fluctuate up and down and never fully charged upto 14.4v even when driving (it used to always show 14.4v after sitting in the Sun or being driven with Lighs on for a journey) - now max it charges to is 13.5v after sitting in the Sun for a whole day

- Just got in the van and it is showing 12.5v on the Camper Control Panel even after being sat in the Sun for a couple of days

- It's doing loads of weird stuff now and I never had an issue for the last couple of years that I've had the solar installed.

- Both the solar control panel and the camper control panel would always show the same voltage in the batteries when driving or if I started the engine briefly when camping, now they show different values all the time and the Voltage fluctuates wildly

The photos show both control panels captured at the same time and the difference in the displays. The first two are with the engine on and captured at same time - the second two show the engine off and captured at the same time.

View attachment 114612 View attachment 114613

View attachment 114614 View attachment 114615

Are my batteries finished? Or is it something else? How do I troubleshoot this?

Thanks if you can help!

I notice you have the system in AES mode, has it always been in this mode? Firmware updates can apparently reset some of the charge settings. I don’t have one of these systems.