6 months ago I added a 10 kWh lithium iron phosphate battery to my rooftop solar system, mostly because evening electricity rates had become ridiculous.

Before the battery, I sent excess midday solar back to the grid for a small credit, then bought power back after dinner. Now the battery charges between late morning and mid-afternoon and runs my refrigerator, Wi-Fi, lights, and heat-pump water heater through the expensive hours.

On a typical weekday, my home uses roughly 7–8 kWh. Solar supplies most daytime demand, and the battery covers about 4–5 kWh after sunset. That has cut my grid consumption dramatically. My utility bill used to average $180 in summer; now it is usually around $95, despite similar air-conditioning use. In spring and fall, I sometimes have a nearly zero energy charge, although fixed delivery fees remain.

My unit uses 26650 lifepo4 cells, according to the specification, and so far the battery has shown no noticeable capacity loss. I keep a 20% backup reserve, so an outage does not leave us completely stranded. During one short outage, the refrigerator and internet stayed on without drama.

The only troubleshooting moment came when the monitoring app showed the battery stuck at 42%. I restarted the inverter as the manual suggested, and charging resumed immediately. A communications cable had loosened slightly during garage work. Now I check that connection whenever I clean around the equipment.