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jasonsparky asked

Victron EV charger does not work off-grid?

After testing and reading through Victron documentation, it appears the Victron EV charger does not function as an off-grid EV charger. This is a little disappointing as one would assume the charger could function in auto mode, as indicated in the product description, to prevent the battery from being discharged below a certain SOC, when used off-grid. It appears the auto function is only operational when the system is used in AC-coupled ESS configuration (grid-connected).

System specs:

- Multiplus2 5KVA, 7.4kW DC-coupled solar, 16kWh self-managed LFP

- Victron EV charger - Firmware version 1.23

- CCGX

Unless I have somehow configured it incorrectly, it appears a regular EV charger could do a similar job. I have read that Victron is working on an improved algorithm, and I'm assuming this would address the lack of off-grid functionality.

As indicated in the attached photo, the EV charger will not function in auto mode even when the batteries are full, and there is ample generation. It just indicates "waiting sun"

20230120-133530-hdr.jpg


ev charging station
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Hi, it is explained in the manual that automatic mode is only for grid connected systems. But you can still use manual mode and define minimum SOC to stop charging. And yes, a new algorithm will be added, functional for offgrid systems.

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jasonsparky avatar image jasonsparky Lucian Popescu (Victron Energy Staff) ♦♦ commented ·
Thanks for the quick reply. During a second test conducted just now, I had the SOC set to 95% in manual mode, and the charger continued to discharge below the cut-off level. However, I was unaware that it would stop charging once the SOC was 1% below the cutout setting, ie, 94%.


Another problem I noticed just now is that it starts 'bouncing" off the min SOC. As the PV starts to recharge the battery and it hits 95% again, the EV charger starts again, which quickly drops the SOC back to 94% and cuts it out. This has now happened 5 or 6 times within a minute, and it cannot be good for the EV. - To fix this issue, it should only begin charging again once the SOC is 1% above the SOC setting, ie, 96%


Also, it would be great and much more convenient if the min SOC setting was also available in the VRM, like the charge current. Thanks


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Lucian Popescu (Victron Energy Staff) avatar image Lucian Popescu (Victron Energy Staff) ♦♦ jasonsparky commented ·

Yes, good idea to increase the hysteresis for minimum soc, we will fix that. For adding it to VRM, not sure if we want that. In there, we are keeping only the basic controls.

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jasonsparky avatar image jasonsparky Lucian Popescu (Victron Energy Staff) ♦♦ commented ·
Thanks again. Just in regard to the min SOC setting in the VRM. I personally believe this setting will be adjusted very regularly depending on the season and weather forecast in an off-grid situation.


For example, I would be happy to discharge the battery much lower if the following day was sunny, but the setting would be set higher during poor weather to reduce potential generator runtime. Therefore having the min SOC setting in the VRM would prove to be very convenient.
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1 Answer
Lucian Popescu (Victron Energy Staff) avatar image
Lucian Popescu (Victron Energy Staff) answered ·

You can do that automatically over node-red, not sure if you are into this. Even based on weather prognosis for the next days.

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