26 May 2026

Which home battery suits your house? Capacity, coupling and connection

Three choices decide which battery suits you — and they are connected. This is how you end up with quotes you can genuinely compare.

Start with the capacity, because it follows from your behaviour and not from your roof. The question is simple: how much electricity do you use during the hours your panels generate nothing — in the evening, at night and early in the morning? That gap is the measure for the number of kilowatt-hours you want to store. A battery much larger than that gap sits half full for most of the day and never earns the extra kilowatt-hours back; a smaller one is empty before bedtime. Your annual statement and the readings from your smart meter answer this better than an average does.

Then the coupling. If you already have solar panels, your inverter determines the route. A hybrid inverter often drives the battery directly (DC coupling) and keeps conversion losses low. If you have a regular string inverter or micro-inverters per panel, the battery sits alongside with its own battery inverter (AC coupling): that works fine and is the coupling work at € 350-900, but it means extra hardware in the quote. If replacing your inverter is on the cards anyway, that is the moment to choose a battery-ready model.

The third choice sits in the fuse box. On a single-phase connection the battery can charge and discharge less power at once than on three-phase. You notice that mainly when you run many appliances at the same time in the evening, or when you want to fill the battery within a few cheap hours. So a single-phase connection does not rule out a battery — there are models for both — but it caps the power. If your consumer unit is full or outdated, preparing the fuse box (€ 350-950) is part of the job.

Put those three answers in your request and the quotes become comparable: capacity in kilowatt-hours, type of coupling and the power your connection can handle. Ask installers to quote the same capacity, otherwise you are comparing two different products; the bands per job are in the price index. If you are unsure about the capacity, choose advice in the request — the installer will then calculate it on your consumption. And remember that we don't sell batteries: you choose brand, capacity and price yourself from the quotes of the installers.