EcoFlow Alternator charger Install in Grand California

[Maidment_Grand]

I have Installed an EcoFlow 800W Alternator charger in my Grand California MY26. This is attached to the engine battery under the passenger side footwell. Charger is situated under the drivers seat where there is loads of space (see image).


When driving I get 800w charging the EcoFlow Delta 3 that is stored and tethered behind the seat (see image). This is works seamlessly with no issues.



So far if I need to top up my Leisure battery I have been connecting the EcoFlow to the Battery charger under the seat by a kettle lead and this works well although I am aware it is not very efficient. I used this for 3 days at Camper Jam and all worked well to give me off grid (Also supported by a solar Suitcase - no need for the alternator charger).

I noticed that the engine battery was getting low and just thought I would try the maintenance charge function on the EcoFlow alternator charger as an experiment. This is where it takes 100W of power from the EcoFlow and puts it into the engine battery (the one it's connected to). This again worked but what I noticed was that it also provided a charge to the leisure battery (see picture). This surprised me but also seems like it could be a good way to charge the leisure battery in a much more efficient way.

I then decided to try the reverse charge feature where it pumps up to 800W into the engine battery and again it also started charging the leisure battery at a much higher rate.


I am not electrically minded as such but to me this seems like a good result and beyond what I was expecting. I believed if I wanted to reverse charge the leisure battery I was going to have to connect the alternator charger to the leisure battery directly which is a much harder job as it need to go through the bulkhead / firewall. I had planned to do this at some point (and just paid £55 for the extra 2m positive lead from EcoFlow!!!).

I am really looking for peoples thought on this - am I likely to break something doing this?
I just did it for a short period as an experiment, but we setoff to France on Saturday for 8 days and 4 will be off grid in potentially dull weather so this would be really useful.

Any feedback appreciated from our group experts!.
Thanks, Nick.

 

[GordonH]

It’s a VW published function of the charge relay that connects the leisure to the starter battery. It will operate (close) under various prescribed conditions one of them being the system senses the starter battery being charged by an external source.

 

[GordonH]

Here is the VW info on when the relay operates

1.4 Notes on function of second battery charging circuit relay -J713-

Switching states of second battery charging circuit relay -J713-

♦ Closed when engine is running safely and there is no energy-critical condition.

♦ Closed when external charging is detected with engine not running.

♦ Open with engine running and energy recovery active, when charge level of second battery is more than 90 % and only low current flows.

♦ Open when engine is not running or when engine start-stop system is in stop mode.

♦ Open for a period of one minute when external charging is detected with engine not running and ignition switched on.

♦ Open at engine start

 

[Maidment_Grand]

It’s a VW published function of the charge relay that connects the leisure to the starter battery. It will operate (close) under various prescribed conditions one of them being the system senses the starter battery being charged by an external source.

Thanks Gordon, really appreciate the response. This sounds like a good result then, I will test on our France trip and if all goes well I will forget the plans to connect to the leisure battery.

 

[Maidment_Grand]

Here is the VW info on when the relay operates

1.4 Notes on function of second battery charging circuit relay -J713-

Switching states of second battery charging circuit relay -J713-

♦ Closed when engine is running safely and there is no energy-critical condition.

♦ Closed when external charging is detected with engine not running.

♦ Open with engine running and energy recovery active, when charge level of second battery is more than 90 % and only low current flows.

♦ Open when engine is not running or when engine start-stop system is in stop mode.

♦ Open for a period of one minute when external charging is detected with engine not running and ignition switched on.

♦ Open at engine start

Gordon do you think 800W is too much to pump in or should be OK?

 

[David M]

That setup looks really good, but what do you do when your camping and you want to turn the drivers seat around?
I have mine in the rear cupboard and the battery under the outdoor shower -but find due to it being there we hardly ever use it... shame really.
On the 800w(max) question, I dialled ours down to 300w as it puts less strain on the alternator.
Have a great trip.

 

[GordonH]

Looking at the specs, the maximum current level from the Ecoflow is stated at 76A but in practice its unlikely to be much over 60A when reverse charging, either way both those numbers are well within the capability of the GCs systems (its a 180A alternator and that will have guided the fuses/wiring/relay rating along with maximum possible battery equalising currents). Remeber that is charging BOITH batteries which will eventually balance. I would question why you would want a fast reverse charge, Your Ecoflow is always present (unlike the engine when you are charging the ecoflow) so I would tune for efficiency..I don’t have the Ecoflow Alternator Charger so cant help on exactly how you would go about tweaking the charge profile to optimise that reverse charging process but the lower the current output the better to minimise cabling losses

 

[Maidment_Grand]

Looking at the specs, the maximum current level from the Ecoflow is stated at 76A but in practice its unlikely to be much over 60A when reverse charging, either way both those numbers are well within the capability of the GCs systems (its a 180A alternator and that will have guided the fuses/wiring/relay rating along with maximum possible battery equalising currents). Remeber that is charging BOITH batteries which will eventually balance. I would question why you would want a fast reverse charge, Your Ecoflow is always present (unlike the engine when you are charging the ecoflow) so I would tune for efficiency..I don’t have the Ecoflow Alternator Charger so cant help on exactly how you would go about tweaking the charge profile to optimise that reverse charging process but the lower the current output the better to minimise cabling losses

Thanks for the info, I think I can adjust the charge but needs to be connected, will have a play tomorrow.

 

[Maidment_Grand]

That setup looks really good, but what do you do when your camping and you want to turn the drivers seat around?
I have mine in the rear cupboard and the battery under the outdoor shower -but find due to it being there we hardly ever use it... shame really.
On the 800w(max) question, I dialled ours down to 300w as it puts less strain on the alternator.
Have a great trip.

TBH, not used in anger yet but only clipped to seat with a bungee, just lean it forward turn chair put back. But only plan to have there when travelling or fully off grid, if I know we have hookup no need to take it.

 

[Maidment_Grand]

Looking at the specs, the maximum current level from the Ecoflow is stated at 76A but in practice its unlikely to be much over 60A when reverse charging, either way both those numbers are well within the capability of the GCs systems (its a 180A alternator and that will have guided the fuses/wiring/relay rating along with maximum possible battery equalising currents). Remeber that is charging BOITH batteries which will eventually balance. I would question why you would want a fast reverse charge, Your Ecoflow is always present (unlike the engine when you are charging the ecoflow) so I would tune for efficiency..I don’t have the Ecoflow Alternator Charger so cant help on exactly how you would go about tweaking the charge profile to optimise that reverse charging process but the lower the current output the better to minimise cabling losses

Hi Gordon, had a play with it today you can change the reverse charge current , I set to 15 A and get 200 W going into the batteries so seems to be very flexible.

 

[Maidment_Grand]

A quick update on this it seems with the alternator charger connected to the engine battery it does not always charge the leisure battery so not reliable. I decided to take the plunge and connect direct to the leisure battery which gives me a totally reliable charge of the leisure battery which works consistently. The other thing I did was connect the extra battery directly to the alternator charger without the Delta 3 and this can be controlled by the EcoFlow app and used to charge the leisure battery. This battery is smaller which means it can stay in place and the seat be rotated with no trouble (Delta 3 needs to be tilted forwards). Very happy now that we can have a few days of grid with no problems.