8 months ago, I added a 10kWh lithium iron phosphate (LiFePO4) battery to my rooftop solar setup because evening electricity use was eating into my savings. The wall-mounted unit sits beside the inverter, and installation took one day. Utility paperwork, unfortunately, took nearly three weeks.

During sunny hours, excess solar charges the battery. After 4 p.m., it supplies the house instead of pulling power from the grid. That has been more useful than I expected. Our peak rate runs from 4–9 p.m., and the battery usually carries the refrigerator, Wi-Fi, lights, television, and sometimes the induction cooktop. Before storage, my monthly bill averaged about $180. Since installation, it has hovered near $70, despite similar weather and usage. On cloudy stretches, the bill rises to around $95, but that still feels like a worthwhile reduction.

I did have one minor scare. After a firmware update, the battery stopped discharging at night and showed a communication warning. I power-cycled the inverter, checked the Ethernet cable, and waited ten minutes, but nothing changed. Support remotely reset the battery controller the next morning, and normal operation returned that evening. They explained that the update had changed the time-of-use schedule. Now I check that setting whenever firmware updates appear.

The battery has also made outages less stressful. It is not whole-home backup; my well pump and electric dryer stay off, but essential circuits keep running for several hours. I appreciate that quiet, automatic transition.

One odd detail: the app displays individual cell data and mentions 18650 cells in its diagnostic screen, although the installed pack is marketed as LiFePO4. I saved a screenshot for the service record but have not needed to investigate further.

Overall, storage has not eliminated my bill, but it shifts solar energy into expensive hours. That saving makes me install another battery.