Running an aircon from the V2L BYD Seal

Continuing the discussion from BYD Atto 3 V2L load testing - Vehicle-to-load power output:

I took a different approach with my V2L set up. I have an Alpha ESS inverter with 10kWh battery and 9.6 Kw solar panels. I just wanted to run my air con overnight from my EV battery as the existing 10kwh Alpha ESS battery just wasn’t up to the job of running an 18000 BTU and 12000 BTU air con overnight (it was down to 20% after 4 or 5 hours)

I installed wiring with ATS switches on my living room and bedroom which disconnect the air cons from the grid and connects to the EV. My bedroom and living room air cons are both 18000 BTU (1.8kW) and I don’t think the EV inverter will run both at the same time so I installed an additional ATS to ensure they only run one at a time using a wifi enabled MCB on a timer from my iPhone app. It works quite well running the living room air from 5.30pm, then switching to the bedroom at 10pm. The EV battery discharges about 10 to 13 Kwh over the 15 hours period before disconnection in the morning and recharging my EV from the solar panels. My daughters 12000BTU aircon is still on the house supply and the 10kWh Alpha ESS battery powers this no problem for 10 hours or so. When the discharge plug is disconnected the ATS’s switch back to the house supply.

1 Like

@Mart, nice work. This is a very clever and interesting solution. Although it is rather complex, it solves your problem.

Can you provide the details of the ATS switches you have used? It looks like they can be easily operated manually as well. I haven’t seem anything like this before

just google ‘automatic transfer switch’

I can’t find it now but there is a video of a guy who stripped one down and explained in detail how they work…I think they were originally designed for isolating the house from the grid when attaching an independent generator.

Originally I just wanted to run my bedroom air con and installed a single ATS, then I decided to add the living room so replicated the bedroom set up. The BYD seal states it has a maximum V2L capacity of 10 amps and if I run both air cons together they would draw 16 Amps so I had to add another ATS switch to make sure they never operated at the same time from the EV. I installed the WiFi enabled MCB as a luxury so I can switch between the two rooms using my iPhone and also set a schedule…that’s why it ended up a bit complicated:)