Watt & Hour was built on a simple premise: battery spec sheets give you numbers, but they don't tell you what those numbers mean when the power goes out. We bridge the gap between technical specs and real household appliances with transparent arithmetic.
Independent research for readers in the United States and Canada.
Sizing battery capacities from 250 Wh weekenders to 3,600 Wh home backup systems. We break down usable capacity, LiFePO4 chemistry, and continuous vs surge inverter thresholds.
Fridges, freezers, CPAP machines, Starlink, and power tools. We catalog real startup surge spikes and steady-state draws so you never overload your inverter.
Calculating realistic runtimes for 4-hour brownouts, multi-day storm outages, RV living, and remote camping. Know exactly what to run before you're in the dark.
Translating obscure manufacturer claims into plain facts. We account for 15% to 20% inverter conversion losses so your real-world runtime matches expectations.
Spec sheets give you numbers, but they don’t tell you what those numbers mean for your fridge, your CPAP, or your laptop. An 800 W microwave draws 1,200 W; a 1,000 Wh battery yields roughly 850 Wh of usable AC power after inverter conversion losses.
We connect the specs to real loads, show the math, and let you check our work. No hype and no scare tactics.
Watt & Hour is produced by an independent editorial team focused exclusively on portable power and home energy resilience for US and Canadian readers.
We are readers and researchers who got tired of misleading battery marketing. Our work is funded through standard affiliate links that cost you nothing and never dictate our findings. Learn more on our how we research and affiliate disclosure pages.
Explore our interactive runtime calculator or check out our beginner guides.