T6.1 Leisure batteries not charging on EHU

[yossarian]

On that general point @yossarian I don’t see vehicle details in many peoples profiles. When I click on a member I often get a message saying they don’t want to share their profile or the OOPS! WE RAN INTO SOME PROBLEMS message. Am I doing something wrong?

To verify vehicle details need to do a lot of tapping on a mobile browser, on a desktop browser it's readily available. I'm sure some long serving forumer can enlighten us?

 

[yossarian]

From what I have gathered the lights and USB points are wired directly from the Leisure batteries but fridge, Heater and Water pump go via the Control Panel. So if the Control Panel has the " Hump " no fridge etc:.
It may also be that the Control Panel on the T6.1 also has some bearing on charging of the rear Leisure Battery but how I have no idea.

Yeah, it appears some loads are automatically switched off if one battery sensor reports a low state of charge. We don't know how the data from the two sensors are combined, however from the wiring diagram we can see that the rear sensor is supplied with incorrect voltage data if the cube fuse is blown. Speculation: this may cause inaccurate and rapidly varying states of charge to be reported.

I hope to test this speculation soon and get some better answers.

 

[yossarian]

It may also be that the Control Panel on the T6.1 also has some bearing on charging of the rear Leisure Battery but how I have no idea.

From the wiring diagram it is clear that there are no mundane modes of failure that could cause the control unit (the panel [E153] appears separate to the control unit [J608]) to alter the state of charge of the rear battery.

It is possible (but highly unlikely) that some esoteric failure modes exist permitting this but these would inevitably result in a flow of VW Germany personnel to observe the failure.

https://vwcaliforniaclub.com/resources/camping-electrical-t6-1-ocean-2-battery.212/download

 

[Rololux]

I'm still not convinced my batteries are working properly. I'm going away tomorrow - batteries were fully charged from hookup, then I went out to buy supplies. When I returned, battery life showed >60 hrs, 12.7v. I turned on the fridge, and hours immediately went down to 19hrs. I then connected EHU again and hours immediately returned to >60hrs.

Is this normal behaviour? I always camp with EHU, so I've never tested how long it would actually run the fridge for on batteries only. Or because I have never done an extended stay on batteries, maybe the control panel simply has never had enough data to give an accurate estimation?? All this does not give me great confidence in the state of the batteries.

 

[WelshGas]

I'm still not convinced my batteries are working properly. I'm going away tomorrow - batteries were fully charged from hookup, then I went out to buy supplies. When I returned, battery life showed >60 hrs, 12.7v. I turned on the fridge, and hours immediately went down to 19hrs. I then connected EHU again and hours immediately returned to >60hrs.

Is this normal behaviour? I always camp with EHU, so I've never tested how long it would actually run the fridge for on batteries only. Or because I have never done an extended stay on batteries, maybe the control panel simply has never had enough data to give an accurate estimation?? All this does not give me great confidence in the state of the batteries.

As has been stated before. The Hours left is a calculation based on the current draw at the time the data is logged and the calculation made. It is a gimmic. The voltage reading is a real life measurement. 12.7v is fully charged. The fridge or heater will switch off when the voltage drops to 11.5 volts.

 

[andyinluton]

I'm still not convinced my batteries are working properly. I'm going away tomorrow - batteries were fully charged from hookup, then I went out to buy supplies. When I returned, battery life showed >60 hrs, 12.7v. I turned on the fridge, and hours immediately went down to 19hrs. I then connected EHU again and hours immediately returned to >60hrs.

The 19hrs was because the fridge was going flat out as you had just turned it on, & the algorithm thinks that the large current draw is going to carry on at that level. Once the fridge has cooled down the current draw drops off & the range extends.
Chances are as you had just got in the van all the lights were on as well?
Same thing happens if you turn the heating on, hours drop massively until the draw has stabilised.

If you left the fridge running without hookup & returned in a couple of hours chances are it would be showing something like >60 hours again.

Note that level 1 or 2 is cold enough for the fridge to store stuff & seems to correspond with level 4 or 5 on the older vans.

 

[Rololux]

So, everything went well on my trip, but as usual I was on EHU every night. I decided to do an experiment when I returned. Batteries were fully charged, and I turned on the fridge at level 4. Checked status on a regular basis, and battery voltage gradually went down as expected. After 69 hours, it reported 11.8v, 50mins remaining, and I got the 'please charge the batteries message'. Over the almost three days, I took the van out once for about a 10 min drive total, with three stops.

While this is just about adequate battery life for a short trip, it does not seem to correct. Is this normal battery life, or do I have a problem?

Thanks for any input.

 

[andyinluton]

So, everything went well on my trip, but as usual I was on EHU every night. I decided to do an experiment when I returned. Batteries were fully charged, and I turned on the fridge at level 4. Checked status on a regular basis, and battery voltage gradually went down as expected. After 69 hours, it reported 11.8v, 50mins remaining, and I got the 'please charge the batteries message'. Over the almost three days, I took the van out once for about a 10 min drive total, with three stops.

While this is just about adequate battery life for a short trip, it does not seem to correct. Is this normal battery life, or do I have a problem?

Thanks for any input.

Level 4 on my T6.1 fridge turns it into a freezer. level 2 is enough to get frozen water bottles if touching the rear wall, level one is sufficient to keep it at about 5 degrees when outside was about 28-30 degrees. The power consumption of the fridge is very different on the different settings.

 

[Stu@rt]

So, everything went well on my trip, but as usual I was on EHU every night. I decided to do an experiment when I returned. Batteries were fully charged, and I turned on the fridge at level 4. Checked status on a regular basis, and battery voltage gradually went down as expected. After 69 hours, it reported 11.8v, 50mins remaining, and I got the 'please charge the batteries message'. Over the almost three days, I took the van out once for about a 10 min drive total, with three stops.

While this is just about adequate battery life for a short trip, it does not seem to correct. Is this normal battery life, or do I have a problem?

Thanks for any input.

Sounds about right to me, I think. I agree with @andyinluton in that I don't feel the need to run the fridge that high and therefore your could reduce demand a touch, by backing that off a little. I think your experiment ratifies the control panel's calculations when it says at 12.8v >60hrs. And possibly a little more with conservative usage. Thanks for the info.