# Home battery (ESS) payback

Typical 48V LiFePO4 rack battery today: **$154/kWh** (the middle of 40 Amazon and eBay listings we check; cheapest $62.50/kWh). Enter your rates to see what storage saves.

Your state  Fills in your state's average electricity rate (August 2026, EIA) and sun hours (NASA POWER). [IP Geolocation by DB-IP](https://db-ip.com)

 Pays for itself in**—**

 Upfront cost**—**

 Saved a year**—**

 Cost per kWh stored**—**

 Rated life**—**

[Today's cheapest 48V rack batteries per kWh →](https://sharpest.ai/per-unit/48v-home-battery-server-rack) [Solar payback →](https://sharpest.ai/tools/solar-payback)

## How the math works

Each cycle the battery delivers **size × usable depth** kWh at the peak rate, and recharging it takes that ÷ round-trip efficiency at the off-peak rate. **Saved a year** = (delivered × peak − delivered ÷ efficiency × off-peak) × cycles per day × 365. **Pays for itself** = (size × $/kWh + other costs) ÷ saved a year. **Cost per kWh stored** = upfront cost ÷ (delivered per cycle × rated cycles): if it is above your peak-minus-off-peak spread, the battery will wear out before it pays back.

Choosing a state sets peak to 1.3× and off-peak to 0.6× its average rate as a rough time-of-use split; replace them with your utility's schedule. The rates, 90% efficiency and 6,000 cycles are starting values, not facts about your battery: use your utility's time-of-use schedule and the cycle rating on the battery's spec sheet. Batteries also need an inverter or hybrid inverter and, for most homes, an electrician; backup value during outages and any incentives aren't counted.

Battery price per kWh as of 2026-11-05: the middle and lowest of 40 current 48V LiFePO4 listings (Amazon, and eBay item + shipping) on our [48V battery price page](https://sharpest.ai/per-unit/48v-home-battery-server-rack).

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As of 2026-11-05. Canonical page: https://sharpest.ai/tools/battery-payback