cadoxa avatar image
cadoxa asked

BMW i3 Charging on an Victron Quattro + ESS LifePo4 system

Hi everyone,

My about to go live system, is comprised of a Victron Quattro 48V/8000VA + Smart Solar MPPT Charger 250/100 MC4 and 24KWh of LifePo4 batteries. My question is;

What's the proper way to configure my system, so that during Winter, the i3 wont use stored energy from the ESS Batteries to charge it self ?

In other words; its ok if during summer it charges from the ESS available power but during winter it should charge exclusively with evergy from my electricity provider.

would love to ear your thoughts. Thankx !!

battery chargingESS
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5 Answers
Riaan Barkhuizen avatar image
Riaan Barkhuizen answered ·

Hi @Cadoxa,

If you are planning to load the ESS assistant there is a nifty feature to limit the maximum discharge from your battery during the night.

It is called "limit inverter power".

Typically this value is set to the house's normal night time consumption (500W-1000W, for lights and fridges etc.), which allows for the battery to be drained slowly while mixing the battery power with energy from the grid.

Below is an example of such a setup. (Inverter limit is set to 1000W)

If you setup this feature and the i3 needs charging it will take a maximum of 1000W to charge the i3 and to provide power to your house. Unfortunately, it does not discriminate between house consumption and charging the battery of the i3, but at least your battery won't be drained in 2 hours.

Not sure if this is your concern.

Best Regards

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That's a smart idea.

further you could connect the i3 charger before the system (if you have a grid meter connected: before the grid meter). disadvantage is that you don't measure the i3 charging in the consumption graphs this way.

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cadoxa avatar image cadoxa Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Hi Daniel,

This is exactly what I needed. If I use a grid meter after the car charger it will not measure the energy transferred to the car but that´s ok cos the Wallbox already does that :). With the use of an inverter, I can switch manually between the position before the system (on winter) and after (summer), cos on summer I will have plenty juice on my batteries for home and car loads.

Again Thanks a lot !!


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cadoxa avatar image
cadoxa answered ·

Hi Riaan, not exactly, but nice workaround though :)

Thankx !!

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cruisey1987 avatar image
cruisey1987 answered ·

Hi @Cadoxa

I'm looking at a similar setup, how to intelligently charge an EV using solar panels.

I'd suggest looking at an EV charger that is optimised for solar power. I'm looking into the Mienergy Zappi for example, which uses a CT sensor on the grid connection to sense when excess solar is being exported and will try to charge the EV to use up any excess and prevent any import from the grid.

During the night however you have the same problem as me where the ESS system will try to charge the EV from battery power, which is somewhat inefficient.

I think you can use the limit inverter power feature above along with the timed charging available on most EVs. If you set the limit to something below 1.4kW between the hours of say 1-4am and set the EV to charge during this time, it will use the minimum amount of battery power to charge the EV (1.4kW is the minimum rate at which most EVs can charge)

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cruisey1987 avatar image cruisey1987 commented ·

Another idea I saw would be schedule the ESS system to charge the batteries from AC at a certain time during the night with a very low SOC goal.

The batteries won't be allowed to discharge until the charging period ends, if you schedule the i3 to charge during this time then it'll charge from the grid only.

Unfortunately all the loads in your house will also be charged from the grid during this time, so it would be good to aim for a quiet time

In any case, please let me know how you get on with your system as I'm currently planning a similar setup

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cadoxa avatar image cadoxa cruisey1987 commented ·

I've implemented a switch to connect the wallbox before the inverter during the Winter and after the Inverter during summer. This way I can warrant that it wont touch the batteries during winter cos the inverter doesnt even know of its existence. The only drawback is that the Inverter wont take in account the Kw injected to the car, but thats Ok cos the wallbox already does that. Its working flawlessly


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dayandnight avatar image
dayandnight answered ·

Hello to all BMW i3 and of course to all other EV owners.

I had the problem in a little bit other way round. I can switch my wallbox to a PV- energy mode only. This means it charges the BMW i3 exclusively with energy with comes from the AC-wired PV. It does it like the Victron ESS. It get information from an additional energy meter how much PV energy will be send back to grid and controls corresponding the EV charge current of the wallbox so grid meter is 0. But since Victron ESS installed, the Multiplus collects all PV energy first and charges the ESS batterie and there is no energy left for my BMW i3 ;-(

I will go to solve this problem with the auxiliary input No. 1 and the assistant "charge current control"

My wallbox is controlled thru a Siemens Logo! and I can easily close a additional potential free contact with is connected to the Multiplus auxiliary input. In this moment this idea isn't already realized and tested. But I am quite sure this will work. I just discovered this challenge, when doing the first Solar based charge of the i3.

Back to the problem of @Cadoxa loading BMW i3 exclusively with energy from the grid, I wasn't aware of this problem. But it will hurt me in winter, too. My idea how it can be solved is in case there is similar to the assistant "charge current control" an assistant like "discharge current control" it should be simply by closing the 2nd auxiliary input during charging an EV-car that only grid energy is used to charge and to prevent of using energy from the ESS batteries. I looked through the list of assistants but I couldn't find an assistant "discharge current control" - Perhaps such an asssistant can be usefull for many other ideas in this direction, too and Victron will help and do such an assistant. [moderator edit: please stop @mentioning mods]

please have a look to this idea. Or there might be already an assistant available which can be used for this and I didn't found.

Looking forward what community thinks.



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Andrew Burnett avatar image
Andrew Burnett answered ·

Came across this tread as i'm looking to start my EV journey and don't want to discharge all my stored energy into my car. Also looking at a Zappi. I'm thinking the best way to stop it using the battery at night is to scheduled charge. setting it low would stop any charge coming out of the ESS battery.

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cadoxa avatar image cadoxa commented ·


I installed an inverter before my powerbox with two positions (winter and Summer), during winter the wallbox gets its power before the grid meter on summer it gets the power after the grid meter this way it will charge from the grid only during winter and will charge from the solar/batteries during summer.


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Related Resources

Additional resources still need to be added for this topic

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