Like countless other people in South Africa, I have invested in an Inverter with a Lithium battery. The battery is a significant part of this investment, so it is essential to get as much runtime out of a single charge as possible.
My inverter is connected to my DB board, meaning all the sockets and appliances in my house are powered by the inverter during a power outage, which, in South Africa, happens frequently and for hours at a time.
Having “always on” power in all the sockets is great and super convenient, but not always smart. As winter encroaches, we start plugging in appliances that draw substantial amounts of power, like electric heaters and blankets. Some electric heaters can draw up to 2 kilowatts of power per hour. Given that the typical inverter system is paired to a 5-kilowatt battery, which means a single electric heater can almost drain the entire capacity in just two hours.
To solve this problem, I built a “smart extension cord” that turns off when the power fails and turns back on once the power returns.…