Size your battery
Pick what you want to keep running, and get an estimated range of backup hours.
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Illustrative estimate. Actual backup time varies.What do you want to keep running?
Add EV charging7.2 kW. Usually paused during an outage.
How long do you need backup?
Estimated backup
30–45hours
How we estimate: the appliances you picked run the whole time, except the heat pump, sump pump and EV charger, which we count at about a third of the time. We base it on the battery setups we install and treat 85% of each battery as usable.