VEVOR 2000W Sump Pump Battery Backup System, LCD Display, Auto Switches to Battery Inverter Power for Sump Pump, Pure Sine Wave, for Basement Protection Emergency Power Outage, Batteries Not Included

As a reference, when using an HD1220-24 12.8V 200Ah battery without an inverter, a setup with two 1/3 HP pumps (starting current: 25.9A each, running current: 9.7A each), where one pump runs every 15 minutes for 5–10 seconds and the other operates 3–4 times per day, can provide approximately 48 hours of backup power. However, if the pump runs continuously, the battery will not last for 48 hours.

The runtime of a 1/3 HP sump pump depends on the pump's operating pattern, whether it is used with or without an inverter, and the connected battery capacity.

150A is basically enough, and the inverter will automatically charge the battery.

Dear customer, You don’t need to recharge the battery separately before connecting the sump pump. This inverter system is designed to work in UPS mode: When grid power is present, it powers your sump pump AND charges the battery automatically at the same time. It is safe and normal to keep the sump pump plugged into the inverter while charging. Your 12-hour battery backup during power outage shows it’s working properly.

The included 50A fuses are built-in replaceable fuses for the inverter internal overload and short-circuit protection, not external inline fuses for battery connection. They are pre-installed inside the inverter fuse slot, no need to install separately. They protect the unit from overload, overcurrent and short circuit.

You can connect two submersible pumps together, but they cannot be started at the same time. Otherwise, the total power will be too high and fail to start. A 200AH battery is recommended for connection.