Solar battery calculators
Home battery tools for the rebate, the size and a blackout, with your state’s rates. Then 12 V tools for caravans, boats and camping.
Home solar batteries
BatteriesBattery rebate calculatorThe federal battery rebate and payback for your battery, with rates for each state.$3,367 on 13.5 kWh until 31 Dec 2026BatteriesBattery buy now or wait calculatorThe rebate you lose by waiting, and how far prices must fall for waiting to pay off.$555 lost on 13.5 kWh by waiting past 31 Dec 2026BatteriesBattery size calculatorWhat size home battery your evening use and solar can fill, with the rebate and payback for common sizes.12.4 kWh for 3 people and 10 kW of solarBatteriesAdd a battery to solar calculatorPayback for a battery on the solar you already have, with the QLD, SA and ACT premium feed-in rules.10.2 years payback on 10 kWh until 31 Dec 2026BatteriesBlackout backup calculatorHow long your home battery runs the fridge, lights and Wi-Fi in a power outage.6.3 days on a full Powerwall 3
12 V batteries: caravans, boats and camping
BatteriesBattery runtime calculatorHow long a 12, 24 or 48 V battery runs a load, with inverter losses and idle draw counted.10.8 hours for an 80 W TV on 100 Ah lithiumBatteriesCaravan fridge battery calculatorThe battery a 12 V fridge needs off-grid, and whether your solar and DC-DC charger keep up.68 Ah for 3 days of a 46 L fridgeBatteriesBattery charge time calculatorHours to charge a battery from a charger, or days from a solar panel, with the slow last stage shown.3.5 hours for 100 Ah lithium on a 25 A chargerBatteriesInverter size calculatorThe inverter size your appliances need, their start-up surge, and the current they pull from the battery.2,700 W for a 2,000 W heater and a fridge
By state
The federal rebate is the same everywhere. Electricity rates and state schemes are not. Each state page says what that state offers and shows the payback at its default rates.