EV Back — Bidirectional Charger that Backs Up the Home from the Car
Charges the car at 7 kW and feeds up to 3 kW back from its battery when the grid fails
Overview
EV Back takes a 220/230 Vac single-phase supply, charges the vehicle at 7 kW and up to 32 A over a 5 m Type 2 cable, and feeds up to 3 kW back at 220 Vac 50 Hz as a pure sine wave — how much a given car can actually deliver depends on the vehicle. Two packages: EVB-73KS pairs with the Home Energy Box (HEB-3K), and EVB-73KP pairs with Home Energy Management (HEM-3K), which adds Ethernet and app control. Up to 3 kWp of solar can be tied in, so the car charges from both the grid and the panels, and its stored energy can be used through the expensive part of the tariff — the datasheet puts the draw at 5-10% of the car's battery per cycle. Developed with support from Thailand's National Innovation Agency (NIA), under Thai patent no. 303002527.
Key Features
- ✓Bidirectional — charges the car at 7 kW / 32 A and returns up to 3 kW to the home (vehicle-dependent)
- ✓Backup output is 220 Vac 50 Hz pure sine wave, for the essential loads during an outage
- ✓Replaces a separate home battery — the datasheet puts the avoided cost at 300,000-500,000 THB per household
- ✓Cuts the bill by drawing on the car through the expensive part of the tariff — 5-10% of its battery per cycle
- ✓Up to 3 kWp of solar can be tied in, so the car charges from grid and panels alike
- ✓EVB-73KS pairs with the HEB-3K box · EVB-73KP pairs with HEM-3K, which adds Ethernet and app control
- ✓5 m Type 2 cable · operates from 0 to 50°C
- ✓Developed with National Innovation Agency (NIA) support · Thai patent no. 303002527