Running our solar battery storage system for eight months has changed the way I think about electricity bills. Before installation, our rooftop solar produced plenty during the day, but we still bought expensive power after dinner.

The installer fitted a 10-kWh home battery in the garage and connected it to our existing inverter. The battery uses a prismatic lithium ion battery cell design, a phrase I had only seen in product specifications before. Its monitoring app shows state of charge, solar generation, and household consumption without making me guess what is happening.

The biggest difference appears between 4:00 and 9:00 p.m. Once the sun goes down, the battery automatically supplies our lights, refrigerator, internet equipment, and induction cooktop. I changed the settings to prioritize self-consumption rather than backup, so nearly every sunny day it reaches full charge by late afternoon. During the utility's peak period, I watch the meter run much more slowly. Our evening electricity use has dropped from roughly 9–11 kilowatt-hours purchased to around 1–2, depending on cooking and laundry.

On the first bill after installation, the energy charge was about $38 lower than the same month the previous year, though weather and rates were not identical. The more meaningful comparison is our last three bills: we are averaging approximately $45 monthly savings. That is not dramatic overnight, but it makes the system feel useful every day, rather than like equipment that only matters during outages.

I did have one minor scare in January. The app showed the battery at 62%, yet the house briefly switched to grid power during a cloudy evening. I checked the breakers, restarted the monitoring gateway, and discovered a loose communications cable. After reseating it, the battery resumed discharge within a few minutes. The installer also updated the firmware remotely, and it.