HELP - why would fridge flatten van battery?

[RedPete66]

Hi guys.
I know there are lots of threads on leisure battery operation etc, but I have a specific question and need some help/advice please.
I have a T6 conversion from Highlife Campers and assumed the fridge ran off the LB so could be run until the LB runs flat (when no EHU available). However, just done 5 days in the Highlands, first 4 on EHU with no issues. Final night had some luxury in a B&B and left the fridge running overnight. Van battery completely flat next morning.

So my question is: Am I being dumb and this was inevitable, or should the fridge run off the LB and the starter battery is protected from running flat?

I've posted photos of my elec set-up and the fridge.

Please help so I can avoid this in future.

 

[Deaky]

The fridge should run from the leisure battery and not the starter. Use the Victron app for your Orion DC-DC charger and make sure that the settings are disconnecting the starter battery when the engine is not running.

 

[RedPete66]

The fridge should run from the leisure battery and not the starter. Use the Victron app for your Orion DC-DC charger and make sure that the settings are disconnecting the starter battery when the engine is not running.

Thanks Deaky. Any chance you can walk me through how to do that and what I'm looking for?
The power control panel would have been switched off during the night - would that have an impact?
Cheers

 

[evans1089]

The power control panel would have been switched off during the night - would that have an impact?

Do you mean you switched off the sargent unit over night?

 

[Deaky]

Thanks Deaky. Any chance you can walk me through how to do that and what I'm looking for?
The power control panel would have been switched off during the night - would that have an impact?
Cheers

Have a look at your Orion Charger, I think there is a green light on it when it's charging (ie connecting the starter battery to the leisure battery). That green light should not be on when the engine is not running. If it is then that is why your starter battery has flattened and you'll probably need to change some settings on the charger.

Download the Victronconnect app from appstore or google play. Go out to your van and open the app. You should see your Orion charger listed. Click on it and select the cog top right corner. Click on engine shut down detection. post a screen shot of the value

It will be similar to this

 

[RedPete66]

Do you mean you switched off the sargent unit over night?

Yes on both the large fuse box and the EC90 control panel.

 

[RedPete66]

Have a look at your Orion Charger, I think there is a green light on it when it's charging (ie connecting the starter battery to the leisure battery). That green light should not be on when the engine is not running. If it is then that is why your starter battery has flattened and you'll probably need to change some settings on the charger.

Download the Victronconnect app from appstore or google play. Go out to your van and open the app. You should see your Orion charger listed. Click on it and select the cog top right corner. Click on engine shut down detection. post a screen shot of the value

It will be similar to this

View attachment 200976

OK, all done and this is what its showing.

Should the control panel be turned ON if running appliances with the van engine OFF?

 

[RedPete66]

No green light on at all whether engine running or not. Is that because it is not plugged into EHU?

 

[MK2Golf24v]

If its wired as per Sargent guidelines, then the fridge has nothing to do with the Sargent unit, it should be wired direct to the leisure battery.

I'd be checking ow the fridge is wired first.

 

[Deaky]

No green light on at all whether engine running or not. Is that because it is not plugged into EHU?

Well your charger appears to be doing what it should. You won't get a green light until the engine has been running for 120s as per your settings. Is it possible that something else flattened your starter battery? Can you post a pic of your starter battery, just to make sure there are no untoward connections to it? Particularly on the -ve side. There should be nothing connected except the original shunt

 

[RedPete66]

Well your charger appears to be doing what it should. You won't get a green light until the engine has been running for 120s as per your settings. Is it possible that something else flattened your starter battery? Can you post a pic of your starter battery, just to make sure there are no untoward connections to it? Particularly on the -ve side. There should be nothing connected except the original shunt

OK thanks. Starter battery pic attached. The only other addition is Audison amp but it’s on a switched live. Defo seems to have been linked to running the fridge.

 

[Deaky]

OK thanks. Starter battery pic attached. The only other addition is Audison amp but it’s on a switched live. Defo seems to have been linked to running the fridge.

View attachment 200998

What's that extra black cable, is it connected to the -ve post?

 

[RedPete66]

What's that extra black cable, is it connected to the -ve post?

It follows the reds cables back through the bulk head out of site.

 

[Deaky]

Are either of these connected to the -ve post?

 

[Deaky]

Ahh, I've just seen you have a Moll battery too. There is a known issue with these, VW were swapping them under warranty.

 

[RedPete66]

Is there an obvious replacement battery to go for?

 

[Deaky]

Just stick your reg in somewhere OEM is a 70/75ah AGM battery. Just to re iterate, there should be nothing except the OEM connection to the -ve post, Anything else should be connected to the body, not directly to the battery.

There is a shunt on the battery that counts the charge in and out, anything that's connected directly to the battery will not be counted resulting in the van thinking the starter battery is fuller than it actually is. Result: Flat battery.

 

[DXX]

I have a T6 conversion from Highlife Campers and assumed the fridge ran off the LB so could be run until the LB runs flat

It’s a lead / acid battery, you can use 50% of the battery capacity, if you discharge it more it will be damaged. The more times it is discharged past 50% SOC the more it will be damaged.

 

[Toffermora]

Just stick your reg in somewhere OEM is a 70/75ah AGM battery. Just to re iterate, there should be nothing except the OEM connection to the -ve post, Anything else should be connected to the body, not directly to the battery.

There is a shunt on the battery that counts the charge in and out, anything that's connected directly to the battery will not be counted resulting in the van thinking the starter battery is fuller than it actually is. Result: Flat battery.

Sorry to jump on this thread but @Deaky I have a bm6 on my battery, should I remove the negative of that from the battery and attach it to the body? If so is there one close to the battery?

 

[RedPete66]

So from what I'm reading here I can conclude that:-
- I have a crap battery that needs to be replaced.
- I have 2 black wires coming off my battery negative terminal that need to be moved to a body ground.
- I still don't have any reason why the fridge would have flattened the battery, even though everything points to that being the only reason why it flattened overnight. The installer has confirmed it is wired to the LB only.

I'll do the battery and earthing changes and see where we are, unless there are any other suggestions??
Cheers.