Solar panels and the CTEK system

[FlyingTexan]

Don’t quite get this CTEK system. It seems to be running on BMW software that keeps it from charging normally. If I leave my overhead switch on to power my fridge/cooler and it drains the battery down overnight. Normally not a big deal except the battery doesn’t charge very well the next day. Does a quick charge to 65% or so then goes low amperage so it just trickle charges and doesn’t actually top itself back off. Drive for an hour and it may be at 70% or something. Meaning day two of using the batteries isn’t an option.

-Has anyone found a way to make it charge normally until the battery is full? This doesn’t really help with being off grid for a few days.
-Is there a way to reverse charge through the Dutch plugs? Wondering if I flush mount solar panels to my Leitner rack if they could leave the battery topped off when it sits so I’m not starting the day at 65%. Right now I’m running a charger to the battery through an extension cord I wedge in my door and not thrilled about that.
-If I connect a battery maintainer under the hood to the jump points on the engine block and the positive on the frame will that charge the batteries even with the system off or is that only for jumping with the power on so the electrical system can regulate the current?

 

[Logsplitter]

Don’t quite get this CTEK system. It seems to be running on BMW software that keeps it from charging normally. If I leave my overhead switch on to power my fridge/cooler and it drains the battery down overnight. Normally not a big deal except the battery doesn’t charge very well the next day. Does a quick charge to 65% or so then goes low amperage so it just trickle charges and doesn’t actually top itself back off. Drive for an hour and it may be at 70% or something. Meaning day two of using the batteries isn’t an option.

-Has anyone found a way to make it charge normally until the battery is full? This doesn’t really help with being off grid for a few days.
-Is there a way to reverse charge through the Dutch plugs? Wondering if I flush mount solar panels to my Leitner rack if they could leave the battery topped off when it sits so I’m not starting the day at 65%. Right now I’m running a charger to the battery through an extension cord I wedge in my door and not thrilled about that.
-If I connect a battery maintainer under the hood to the jump points on the engine block and the positive on the frame will that charge the batteries even with the system off or is that only for jumping with the power on so the electrical system can regulate the current?

Yes a smart battery charger will work when attached to the jump start posts under the bonnet. In the past I regularly charged my batteries using both a mains smart charger and portable solar panels, connected to the jump start post under the bonnet.
I now have 270 watts of solar connected permanently to my Alucab roof and controlled via a Victron mppt controller in the battery compartment. I can confirm that solar keeps both batteries fully topped up even during the U.K. winter.
Hope that helps.

 

[Tom109]

The smart alternator is pretty bad and backs off at an unreasonably low state of charge. My guess is this is for fuel economy reporting, but it’s not practical for the Grenadier’s intended use.

I put 200W of solar on my roof and an MPPT controller connected to the main battery. When I’m not parked in the garage my SoC is always 91%+. The screen grabs below show the modest top-up provided by solar. If my fridge was running you’d see a significantly larger drop overnight, as well as solar + alternator recharge.