Home Battery Storage 101

A home battery is really two separate purchases bundled into one decision: a piece of hardware with its own warranty and degradation curve, and a strategy for how you'll actually use it — backup power, time-of-use arbitrage, or both. Getting the strategy wrong is a far more common regret than getting the hardware wrong.

Lifespan and warranty terms matter more than the spec sheet headline

Every battery loses some usable capacity every year it's cycled, and warranty terms are written against both a calendar term and a cycle count — whichever comes first. Our battery lifespan and degradation guide walks through how to read a capacity-retention warranty and what actually drives faster or slower degradation in normal use.

You don't need solar panels to get value from a battery

Batteries paired with time-of-use electricity rates can be worth installing even without solar — charging on cheap off-peak power and discharging during the expensive peak window. Whether that math works depends entirely on how wide the gap is between your peak and off-peak rates. Our guide to battery storage without solar covers when that arbitrage is worth it and when backup power alone is the better justification.

Compare specific models, not just capacity

"10 kWh of battery" isn't one product — continuous power output, warranty length, and stackability vary meaningfully between models. We've reviewed three of the most common home batteries directly: the Tesla Powerwall 3, the Enphase IQ Battery 5P, and the FranklinWH aPower 2.

Run your own numbers

Use our Battery ROI Calculator with your actual time-of-use rate structure rather than a generic national average — the payback math changes substantially depending on how big the gap is between your peak and off-peak electricity prices.