Battery Capacity

This article explains the battery capacity required for home and property solar during periods when there is no solar or other energy input. Solar capacity is now cheap. Battery capacity is increasingly costly. Quality solar modules produce usable energy even under light cloud. Install as much solar as you can. This ensures batteries fully charge quickly most of the time.

When determining the battery capacity required – never skimp on solar. Excess battery capacity is like having multiple bank accounts. It increases the cost of storage for no gain.

Battery capacity required for home and property solar

Battery capacity required for home and property solar is such that it is still 85% charged around dawn. Furthermore, it should reach 100% by midday. If not, add solar until it is. A 45 kW/h battery bank typically needs at least 5 kW hour solar. The amount depends on your location, however, more is always best. There is no risk of overcharging because the solar regulator prevents that.

Battery type depends partially on space available. If scarce, consider lithium-ion (LiFePO4). If ample, an AGM battery bank is initially far cheaper. AGM batteries are often sold secondhand. They are mostly ex-standby applications. Many are unused.

This battery bank has 16 by 230 amp hour gel cell batteries. Pic:

For maximum input year-round, for home and property solar, tilt solar modules at your latitude angle. To increase summer input tilt them closer to horizontal. To increase winter input, tilt 10-15 degrees more than latitude angle.



Our book Solar Success (for homes and properties) explains all in this area. Solar That Really Works! does likewise for cabins and RVs.