Observed arrival · 2026-09-21
Backup Hours: A Battery Runtime Planner
A browser-based calculator that estimates how long a UPS, inverter, or home battery can run an essential appliance load.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- UPS, inverter, and home-battery planners
- Worth noticing
- It shows a practical runtime range alongside the central estimate instead of presenting battery labels as exact.
Field notes
The calculator accepts watt-hours or amp-hours with bank voltage, applies usable-capacity and inverter-efficiency settings, and lets visitors build an appliance load. Its output includes both a point estimate and a wider range; the example uses 1,200 Wh, 150 W, and 918 Wh of usable AC energy. Guidance covers series and parallel battery banks, surge limits, temperature, battery age, and the distinction between watts and VA.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
†AdsAdvertising visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue