8 months ago I added a 10kWh lithium iron phosphate battery to my rooftop solar system because our evening electricity use kept eating into the savings. Before the installation, I sent surplus solar back to the grid during the day and bought power back after dinner. Now the battery charges from the panels first, then runs the fridge, lights, router, and heat pump when the sun is gone.

The biggest difference shows up during peak hours. On my utility’s time-of-use plan, I used to see expensive rates between 4:00 and 9:00 p.m. My monitoring app now shows the battery discharging through that window, and my monthly bill has dropped by roughly 35%, from about $180 to $115 on average. It is not a dramatic off-grid transformation, but saving $65 each month makes the system feel worthwhile. In sunny months, I sometimes finish the day with 25% remaining; during cloudy weeks, I still import some electricity, especially after running the dryer.

I chose cells advertised as a "280ah battery eve" setup, though the usable capacity is lower than the headline number after reserve settings and inverter losses. I set a 20% minimum state of charge, which gives me backup without sacrificing too much daily savings.

One evening, the battery stopped discharging at 62%. I initially blamed the solar battery, but the app showed a grid outage notification from a brief utility flicker. After checking the breaker and restarting the inverter, I found the backup reserve mode had been enabled. I switched it back to self-consumption, and normal operation returned within a few minutes. That small scare taught me to check settings before assuming hardware failure.

For me, the best part is quiet routine: I rarely think about electricity prices now, and I can see real-time solar production, battery state, and savings.