12V / 24V / 48V Picker

Enter your biggest load and see the battery current at 12V, 24V and 48V, and which system voltage suits you.

Pick your system voltage before you buy a battery, inverter or charge controller, because they all have to match it. This picker uses the same simple rule as our guide. Everything is worked out in your browser. Nothing is saved or sent anywhere.

1. Your system

Your biggest load is everything you'd run through the inverter at the same moment. The Daily Power Needs Calculator works it out as your peak load.

Running watts of everything on together.
Used to show the battery size at each voltage.
The battery supplies a little more than the load uses (50 to 100%).
Growing systems are usually best at 48V.

2. Results

How it was worked out

    Before you rely on it

    • The rule used here: up to about 1,500W, 12V is usually fine. About 1,500 to 3,000W, 24V is usually the better choice. Over about 3,000W, or a system that will grow, go 48V. These are rules of thumb, not limits.
    • Check that the battery's maximum continuous discharge current, its BMS, the fuses and the cables can all handle the current shown.
    • Panels wired in series add their voltages. A string can go well over 120V DC, which is no longer extra-low voltage. Check it with the MPPT Controller Size Calculator.
    • Buy the battery, inverter and charge controller to match. Changing system voltage later usually means replacing most of them.
    • This is a planning estimate only, not a system design, wiring specification or safety assessment. Real results depend on your location, weather, shading and the gear you choose. Check the manuals and specifications for your panels, battery, inverter and charge controller.
    • Safety: in Australia, any work on 240V AC wiring, including connecting an inverter, battery or solar system to a home's switchboard or fixed wiring, must be done by a licensed electrician. Grid-connected systems also need approval from your electricity network.

    Next steps

    Read why voltage matters in 12V, 24V or 48V? Picking Your System Voltage, then size the inverter.

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