HELP! Leisure Batteries not charging properly

[Dippa]

Hi all, looking for some advice with the leisure batteries on my T6.1.

I’ve noticed they don’t seem to charge from the alternator while driving unless I press Max Charge.

Last week I drove for over 2 hours and the control panel stayed around -1A and wasn’t charging my batteries. So I pressed Max Charge and it immediately jumped to around 25A. I then switched Max Charge off and it continued charging normally, fluctuating as I drove like I’d expect.

I thought it might have been a one-off or just the smart alternator doing its thing, but it’s doing exactly the same again today unless I no real I press Max Charge.

Is this normal, or does it sound like there’s an issue with the leisure battery charging system?

I have the 300W solar and an 800W EcoFlow alternator charger connected to the leisure battery, but I’ve powered the EcoFlow down and the issue is still the same.

Any help appreciated!

 

[temporarysecretary]

Without max charge the van will charge to 80%. Max charge allows it to go to 100%.

The solar almost guarantees you are probably reaching 100% every day.

The batteries dont need charging so they aren't being charged to get better economy out of the van.

Check the stats of your MPPT and it should back this up.

 

[Dippa]

Without max charge the van will charge to 80%. Max charge allows it to go to 100%.

The solar almost guarantees you are probably reaching 100% every day.

The batteries dont need charging so they aren't being charged to get better economy out of the van.

Check the stats of your MPPT and it should back this up.

Thanks for the reply, that makes sense regarding the 80%/100% charging strategy, but there’s another reason I’m wondering if something isn’t behaving quite right.

My EcoFlow 800W alternator charger is set to start charging the Delta 3 when the leisure battery side reaches 12.9V. When driving I’m seeing around 13V and can see that the solar is keeping the leisure batteries topped up, but the EcoFlow still isn’t charging the Delta 3 despite being above the 12.9V threshold.

But if I lower the EcoFlow threshold, it starts pulling around 25-35A from the leisure batteries, basically behaving as though the van is stationary rather than taking advantage of the alternator.

Soon as I press Max Charge, everything changes I see around +25/+35A going into the leisure batteries and it fluctuates with driving/acceleration as I’d expect. If I then switch Max Charge back off, it continues charging beyond the 80% you mentioned.

But that’s the bit I don’t understand. If the batteries simply don’t need charging because they’re already at the normal 80% target, why does activating Max Charge seem to wake up the alternator charging, and why does it then continue normally after Max Charge is switched back off?

 

[Betsycalifornia]

Can I ask where you connected your Ecoflow alternator charger to? I’m asking as that behaviour is alien to mine. I’ve only got the ability to protect the main engine starter battery and not the leisure batteries unless I reverse charge

 

[Dippa]

Can I ask where you connected your Ecoflow alternator charger to? I’m asking as that behaviour is alien to mine. I’ve only got the ability to protect the main engine starter battery and not the leisure batteries unless I reverse charge View attachment 152010

Mines connected directly to the leisure battery under the passenger seat. I chose to install this way so my solar will also charge it and I can reverse charge back tot the leisure batteries if needed