Best Home Battery Storage UK 2026: Compare — comparing the top 15

What to look for in home battery storage

Usable vs gross capacity: A 10kWh battery with a 90% depth of discharge gives you 9kWh of usable storage. Always compare usable figures — gross capacity numbers flatter the headline spec.

Round-trip efficiency: 90%+ is good; lower means more of your solar surplus is lost in the conversion process. A 95% round-trip efficiency means for every 10kWh you store, you get 9.5kWh back out.

AC vs DC coupling: DC coupling (battery connected before the inverter) is more efficient for new solar installs because power only goes through the inverter once. AC coupling is simpler for retrofitting a battery onto an existing solar system.

LFP chemistry: Lithium iron phosphate batteries last longer (4,000+ cycles vs ~2,000 for NMC — manufacturer datasheets, e.g. BYD LFP specs), run cooler, and are safer. LFP is now the default chemistry for home batteries — prefer it unless there's a compelling reason otherwise.

Common mistake: Sizing the battery to your total daily electricity usage rather than your solar surplus. The two numbers can differ by a factor of three or more. Stage 4 of the guide walks through the sizing calculation.