V2L enable using API

[haywire]

Anybody know if the V2L can be enabled using the API? I can enable it on the infotainment screen, just curious if there is any automation potential using the API

 

[wattmatters]

I see no ability to control V2L discharge operation from the SAIC API controls I have in the Home Assistant integration.

The controls for charging are there but not discharging.

I have V2L running now - charging my home battery as it's a dismal day here. We get free grid power 12-2PM so I load up the home and car battery in that time. Handy on days like today when the solar PV won't generate much.

Normally I don't use the V2L for this but it works well when/if I need it.

 

[haywire]

I see. Shame V2L is not exposed. Thanks for checking. Dismal day here too. I might also plug in.

 

[wattmatters]

I recharged during the 2-hour free period and then put it back to duty but set a discharge cut off at 80%. It's effectively powering the home and keeping the home battery at float until then. It's down to 83.2% at 5:38PM so I guess it'll keep us going another hour or so, depending on what stuff gets turned on. Then the home battery takes over.

 

[Barrie]

I have V2L running now - charging my home battery as it's a dismal day here. We get free grid power 12-2PM so I load up the home and car battery in that time. Handy on days like today when the solar PV won't generate much.

Which battery charger do you use in between your V2L connection and your home battery ?

 

[wattmatters]

Which battery charger do you use in between your V2L connection and your home battery ?

It's a cheapish 4 kW all-in-one off-grid hybrid inverter I picked up some years ago. A type of Voltronic clone.

I used it as a way to provide backup power for the home when coupled with some ex data centre batteries I also picked up for not a lot of $ along with some PV I put on the garage roof. Coupled with Solar Assistant and integrated with Home Assistant, the control is amazingly flexible and programmable.

I've since (2 years ago) replaced it with an 8 kW unit and LiFePO4 batteries which power the home at night (except for some high power stuff). Keep the lead acid batteries as my reserve capacity.

The old inverter wasn't doing much so I have now set it up to act as a supplementary charger if/when required. Mostly to enable the EV to provide extra redundancy. We get a lot of power outages, this is those lasting for longer than 5-minutes:

But since we also now get free grid power a couple of hours every day, if the day is poor for PV production I see no reason not to take advantage of it. Dump extra into the car and then let it supply that free energy to the home via the home battery.


It's not something I'll do regularly, just during these poor weather periods. Our district has been on flood watch over last few days and that comes with an increased risk of power outages, hence I liked to preserve battery capacity where I reasonably can. The rest of the occupants have no idea, they just carry on as normal.

I see my MG4 (64 kWh Essence) did cease discharging when it reached 80% SOC, right at ~ 7PM, so that extended our home battery coverage by several hours.

The weather improves from tomorrow so our solar PV will be able to charge the batteries OK. I have 11 kW of grid tied PV and 2.2 kW of off-grid PV.

 

[Barrie]

Thanks for the detailed reply but I was trying to determine how you connect your V2L lead from the car to your home battery. I assume it's via a battery charger ? If so, which one do you use ? Thanks again.

 

[wattmatters]

Thanks for the detailed reply but I was trying to determine how you connect your V2L lead from the car to your home battery. I assume it's via a battery charger ? If so, which one do you use ? Thanks again.

The first sentence of my previous reply answered your question.

This sort of thing (but not this specific item). There are hundreds of models like this random one from a quick Google.

Solar Inverter 5KVA 4000W Pure Sine Wave 48V 230V Hybrid Inverter

SPECIFICATIONS Is_customized: Yes Weight: 13.0kg Wave form: Pure sine wave DC/AC Inverters - 54 Energy - Renewable Energy Store

54energy.net

Or could just use a plug in 48 V charger designed for these batteries as well (another quick Google):

48V10A-20A-30A Industrial Grade Lithium Battery Charger for LiFePO4 Battery | eBay

For 52.8V LiFePO4 Batteries. Max charging current: 10A, 20A, 30A. Constant current 10A, 20A, 30A. NEVER turn on before connect lithium battery positive and negative correctly!

www.ebay.com.au

Obviously you'd need to choose a charger suitable for your battery chemistry and charge voltage needs.

I prefer the first option as it allows me to set charge voltages I prefer to use (in 0.1 V increments) and the DC charge current is also adjustable (in 10 A increments).

 

[Barrie]

Many thanks again. It seems clearer to me now. So you plug your V2L directly into your old inverter on the AC "in" and the inverter takes care of the battery charging ? My set up is different and I have my inverter feeding the house via SBU (solar, battery, utility) but my 5kWh battery sometimes does not see us through the night and I was looking for a way to utilize the car's V2L to top the battery up during the night. So, a regular battery charger connected to my V2L and my LifePO4 battery should do the trick ?

 

[wattmatters]

Many thanks again. It seems clearer to me now. So you plug your V2L directly into your old inverter on the AC "in" and the inverter takes care of the battery charging ?

Yep!

So, a regular battery charger connected to my V2L and my LifePO4 battery should do the trick ?

Yep, that would work.

The thing I like about using the little inverters is they can be controlled/monitored with Solar Assistant, and in turn via MQTT, Home Assistant. So you can set up automations to manage it when operating. I also don't like the voltage many of the plug in chargers work to (>58 V).