Battery Backup Sizing Simulator

Select appliances, then estimate runtime and required battery kWh for your target outage duration.

1. Appliances
2. Battery Size
Capacity 13.5 kWh
*Standard Tesla Powerwall is 13.5 kWh
Usable battery (%) 90%
Inverter efficiency (%) 90%
Battery health (%) 100%
Target outage duration (hours) 8 h
Required capacity
0.0 kWh
Based on your load and efficiency settings.
GRID OFFLINE

Estimated Runtime

0
Hours
0 W
Current Load
13.5 kWh
Available Energy

Energy Hogs: What Drains Your Battery?

Heating elements are the enemy of battery storage. Appliances like electric stoves, hair dryers, and water heaters use massive amounts of power (often 1500W+). Running these during a blackout can deplete a standard 13.5kWh battery in just a few hours.

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