Cab battery level mystery

[Gonestravaiging]

Hi, can anyone help a newbie - new to this forum and a new campervan owner - with a cab battery issue? The battery is showing practically empty, about 4V, on my control panel, but there's no warning light on the dashboard and the engine starts without problem. Could the reading be faulty, and if so what's the likely cause? I read somewhere that it might be something to do with the fuse for the solar panels. Many thanks for any input.

 

[Richard n Ann]

If you have a multimeter, check the voltage at the panel, it could be an LCD display problem, faulty panel or wiring.

 

[Tombola]

4v? No defo wrong.
Must be a problem with the panel etc as post above.

 

[IanRJ]

Depending on the make of your setup you may need to recalibrate it. That is sometimes necessary for a Sargent unit for example.

 

[Gonestravaiging]

Thanks for that, and for the welcome! I don't have a multimeter but I'll pick one up today. Think it may be a display problem. Lots to learn.

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[Gonestravaiging]

Thanks IanRJ, it is a Sargent unit.

 

[peterc10]

Are you sure that you are looking at the cab battery charge and not the habitation battery?

 

[IanRJ]

Thanks IanRJ, it is a Sargent unit.

If you have a manual for the unit, look for the recalibrate item. Some times the scale of the levels is out of sync with the units of actual measurement. I think it will be under the extended or dealer menu. Don’t have my van at the moment so can’t check how to do it.

 

[Gonestravaiging]

Hi, yes it was the cab battery. I plugged the van in overnight and this morning there was another development - none of the electrics working in the van. Turned out it needed a new 20V fuse on the Sargent unit. Now the control panel is showing the cab battery back at 13V. Not sure why that would affect the battery reading - but at least I am now the owner of a multimeter. Many thanks for all your suggestions. Delighted I've joined up.

 

[Richard n Ann]

That's good what multimeter did you get?

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[autorouter]

Turned out it needed a new 20V fuse on the Sargent unit. Now the control panel is showing the cab battery back at 13V. Not sure why that would affect the battery reading

Many MHs don't have a separate wire for measuring the battery voltages. They use any wire already there, maybe for the fridge or the split charge relay for charging the leisure battery. A 20A fuse is the standard value for a 3-way fridge 12V element.

 

[Gonestravaiging]

That's good what multimeter did you get?

Just a basic Laser battery/alternator tester from Halfords. No time to check reviews and order online!