In this article, we'll explain how to install multiple batteries and how to safely unlock them to discharge at higher power levels.
Installing Multiple Plug-In Batteries
Always connect the Plug-In Battery directly to a wall outlet. Never connect it to a power strip, Energy Socket, or other plug-in peripheral devices.
Charging with Multiple Plug-In Batteries
When you connect multiple batteries, the charging power increases in steps of 800 watts:
• 1 battery → 800 watts
• 2 batteries → 1600 watts
• 3 batteries → 2400 watts
• 4 batteries → 3200 watts
When connecting electrical devices, it's important to consider overloading the electrical circuit and the phase it's on. Otherwise, the circuit may trip for safety reasons.
Connecting multiple batteries? We recommend not placing them on a circuit with other high-consumption devices that use a lot of power for extended periods, such as electric heating, washing machines, or condenser dryers.
The rule of thumb for more than 3 batteries is to distribute them across circuits or use a dedicated circuit where no other devices are connected.
Discharging with Multiple Plug-In Batteries
When connecting multiple batteries, the default discharge power remains 800 watts. For safety reasons, you shouldn't and don't want to supply more power to a circuit that also has other devices connected.
Want a higher discharge power (up to 3200 watts)? Then the batteries must be connected to a dedicated circuit(s) where no other devices are connected. We recommend using an electrician for this.
Single-phase home connection: You can connect the batteries to one separate circuit: 800 watts/1600 watts/2400 watts/3200 watts. When connecting electrical devices, it's important to consider overloading the electrical circuit and the phase it's on. Otherwise, the circuit may trip for safety reasons.
Three-phase home connection: You can connect the batteries to one separate circuit: 800 watts/1600 watts/2400 watts/3200 watts. Or distribute them across different circuits and phases, each with its own wall outlet.
Always check the maximum connection capacity per phase. Each battery adds 3.5A. Ideally, place the batteries on the same phase as your solar panels. This isn't always possible, as sufficient capacity within the phase is needed to connect multiple batteries on that phase. In that case, we recommend distributing batteries across phases.
You can unlock a higher discharge power via the HomeWizard Energy app at Settings > Devices > Plug-In Battery > Battery Group Settings > Safety Restriction
Why is a dedicated circuit important, and are there other ways?
Why is a dedicated circuit important, and are there other ways?
There are other ways to 'safely' install and unlock multiple batteries, but the risk of user error is significantly higher and therefore not recommended by us.
For example, you could distribute and unlock batteries across different circuits. This is safe, but there's a greater chance of errors. Does the user know for certain these are separate circuits and that they'll stay that way?
You could account for the maximum power already present on the circuit, but this has an even higher risk. There's typically no control over everything plugged into each outlet, and whether it might draw much more power than expected due to an obscure fault or malfunction.
It’s like driving faster than advised: it might work, but it’s not safe. If no one else is driving, you might consider it safe. Or as a professional driver, it 'could' be safe. But there are no guardrails along the road and the asphalt might have longer braking distances or behavior than the driver accounts for.
Our experience shows that most people can't fully assess or oversee the risks (sometimes even electricians can't).
That's why our advice remains the same: only unlock when no other devices are connected to the circuit. If you unlock despite the above advice, it's at your own risk, just like driving 75 mph on a 30 mph road. It doesn't affect the warranty, but it does affect the safety of your home.
Smart Control of Multiple Batteries
Each battery responds dynamically to energy surplus or deficit in your home. This happens based on measurements via the P1 Meter on the smart meter. The battery detects the difference and steers consumption toward zero.
When charging demand is less than 800 watts, one battery is controlled continuously. When it's more than 800 watts, one or more batteries activate and the power is distributed evenly. This achieves the highest efficiency by optimally scaling multiple small inverters up and down compared to one large inverter.
The system deliberately doesn't balance per phase in a home with a 3-phase connection. The smart meter adds up the total of the 3 phases. It doesn't matter which phase you consume or supply power on, as long as they collectively reach 0. Balancing the total of the phases achieves higher efficiency than balancing each phase to 0.
With 4 batteries, you can charge up to 3200 watts and discharge up to 3200 watts (if unlocked on a dedicated circuit without other devices).