Battery cut off voltage?

[simonbevan]

1997 California coach 2.5tdi
The fridge is switching off after less than 24hours due to voltage cut off being reached. This is happening at 12.1v on the display. Is that correct? I thought it would be lower than that.

Fridge/cooler appears to be working well and typically set to 2C. It’s a single exide 1600 AGM leisure battery.

 

[WelshGas]

1997 California coach 2.5tdi
The fridge is switching off after less than 24hours due to voltage cut off being reached. This is happening at 12.1v on the display. Is that correct? I thought it would be lower than that.

Fridge/cooler appears to be working well and typically set to 2C. It’s a single exide 1600 AGM leisure battery.

Normally that cutoff is 11.5v. However I'm not sure if that voltage is measured at the Control Panel or at the Fridge Controller. Depending on the resistance of the circuit from battery to fridge then the fridge controller might be seeing a lower voltage than the Control Panel.
Conversely if the Control Panel monitors the voltage then the voltage maybe dropping to 11.5v momentarily on fridge compressor startup, so fridge switches off, but Control Panel shows resting voltage of 12.1v.

 

[sidepod]

Cut off voltage on a T4 is 10.5v.

Bizarrely I have a similar issue at the moment.
I’m thinking a failed leisure battery or some discrepancy between actual battery voltage and display.

I’m away at the moment but I’ll investigate when I return.

Try putting a voltmeter directly across the leisure battery, see if the reading correlates with the main display.
It could be something to do with the shunt, not normally an issue on 4s but possible.

Try to keep this thread live so we can share Intel.

 

[WelshGas]

Cut off voltage on a T4 is 10.5v.

Bizarrely I have a similar issue at the moment.
I’m thinking a failed leisure battery or some discrepancy between actual battery voltage and display.

I’m away at the moment but I’ll investigate when I return.

Try putting a voltmeter directly across the leisure battery, see if the reading correlates with the main display.
It could be something to do with the shunt, not normally an issue on 4s but possible.

Try to keep this thread live so we can share Intel.

10.5 v doesn't protect the battery at all, especially if the voltage regularly drops to that level. Will certainly shorten battery life.

 

[sidepod]

Just saying that’s what the heater and fridge are set on a 4

 

[simonbevan]

Thanks, I will have to watch it closely to see when it cuts out. Just replaced the original charger with a direct replacement made by Fraron. I have a single gel leisure battery and just run the diagnostics using the overhead display. Dip switches all in the off position but it’s showing 1b which suggests it thinks I have two leisure batteries, could someone else check what theirs says? Also the cooler test shows 0.0a with a minor fluctuation to 0.2a when the compressor first fires up. That doesn’t seem right, should show 4 to 5a according to the wiki. Any suggestions appreciated

 

[simonbevan]

Thanks, I will have to watch it closely to see when it cuts out. Just replaced the original charger with a direct replacement made by Fraron. I have a single gel leisure battery and just run the diagnostics using the overhead display. Dip switches all in the off position but it’s showing 1b which suggests it thinks I have two leisure batteries, could someone else check what theirs says? Also the cooler test shows 0.0a with a minor fluctuation to 0.2a when the compressor first fires up. That doesn’t seem right, should show 4 to 5a according to the wiki. Any suggestions appreciated

Just tried it with dip switch one changed and it showed 2b. So I guess it was ok. 1b meaning one battery and 2b meaning two batteries.