Autosleeper battery monitor (1 Viewer)

[simbadog]

AS Monitor Alarm triggered. Got another battery alarm text this morning on my 2021 Autosleeper Broadway.
Van has EHU off but has the solar on roof.
Had 2 alarms a couple of days ago & when I went to van the leisure battery read 0v, I firstly checked the inline 25amp fuse by leisure battery & it seemed OK but a poor fit.
Fiddled about with things & leisure battery came back up showing 12.1v, I presumed it was due to the poor connections on the fuse holder & yesterday replaced it with a better quality one.
All good yesterday & despite little sun everything looked OK.
This morning I get another battery alert text, go out to van & leisure battery shows 0v ! (See first picture)
I plugged it into EHU & instantly get a reading of 12.5v ??? (see second picture)
Any thoughts please?

 

[peterc10]

The voltage figures on the left will show the charging voltage, not the standing voltage, of each battery. When you switch on the EHU that charger has started charging those batteries. By the look of it your leisure batteries are as flat as pancake, with zero standing voltage and your engine battery has a standing voltage of 12.1, which is quite low, and at the moment is not being charged. .

I would guess that you are simply not getting enough solar energy to charge both batteries, which is not uncommon in the winter. What is the wattage of your solar panel? I also suspect that your system will only allow you to charge either the engine battery or leisure battery. In that case you have only been charging the engine battery, but still not enough.

Either increase your solar array or keep it on EHU. If you can set your charger to change both batteries do so. Otherwise set it to charge the leisure battery and fit a Vanbitz Battery Master that will provide a trickle charge to the engine battery. You should also check the state of your leisure batteries as they may well have been damaged by the low voltage.

 

[simbadog]

The voltage figures on the left will show the charging voltage, not the standing voltage, of each battery. When you switch on the EHU that charger has started charging those batteries. By the look of it your leisure batteries are as flat as pancake, with zero standing voltage and your engine battery has a standing voltage of 12.1, which is quite low, and at the moment is not being charged. .

I would guess that you are simply not getting enough solar energy to charge both batteries, which is not uncommon in the winter. What is the wattage of your solar panel? I also suspect that your system will only allow you to charge either the engine battery or leisure battery. In that case you have only been charging the engine battery, but still not enough.

Either increase your solar array or keep it on EHU. If you can set your charger to change both batteries do so. Otherwise set it to charge the leisure battery and fit a Vanbitz Battery Master that will provide a trickle charge to the engine battery. You should also check the state of your leisure batteries as they may well have been damaged by the low voltage.

Thanks for reply

Think the factory fitted solar is only 80w, the sargent system has a smart selection that supposedly selects which system to charge?
Removed the Sargent EM40 interface unit with the fuses in it & cleaned / checked all connections, then
turned off the EHU which has now been on for 20 minutes & leisure battery showing as 13.1v.
It's all too clever for it's own good
Leisure is lithium.

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[GeoffnDee]

If the control is a Sargent EC480 it may need recalibrating due to the poor connection you found (if your battery is not actually flat) and details are on the Sargent Electrical website (Support) or the same information can be found on page 3 of Motorhome technical articles in the Resources section (It is for an Autotrail but with the same control panel)

 

[simbadog]

If the control is a Sargent EC480 it may need recalibrating due to the poor connection you found (if your battery is not actually flat) and details are on the Sargent Electrical website (Support) or the same information can be found on page 3 of Motorhome technical articles in the Resources section (It is for an Autotrail but with the same control panel)

It's got a Sargent EC700 unit

 

[peterc10]

Thanks for reply

Think the factory fitted solar is only 80w, the sargent system has a smart selection that supposedly selects which system to charge?
Removed the Sargent EM40 interface unit with the fuses in it & cleaned / checked all connections, then
turned off the EHU which has now been on for 20 minutes & leisure battery showing as 13.1v.
It's all too clever for it's own good
Leisure is lithium.

Probably the 13.1v will be from the solar charge, but the current will be very low, so it will take many weeks to charge the batteries up, if at all. You need to keep the EHU on for at least a couple of days to get the leisure batteries fully charged. 80W solar is not going to give you enough charge over the winter to keep your batteries topped up, so you need to keep the EHU connected all the time otherwise your problems will just come back.

And another problem is that lithiums should never be completely discharged. Not sure whether that will be fatal or just shortening their life.