Which home battery suits you? How to choose

It is tempting to start with brands and spec sheets. The other way round works better: first measure how much power you use during the hours your solar panels produce nothing, then look for a battery that matches. A battery only earns money on power that actually flows through it. Every kilowatt-hour of storage you rarely use is dead capital.

In practice: open your energy app or smart meter data and check what you use between roughly five in the afternoon and seven in the morning. That evening and night use varies far more between households than the yearly total suggests, certainly with a heat pump or electric car in the mix. We size the battery on that number, not on the average household from a brochure.

We regularly see two pitfalls in quotes from elsewhere: a battery bigger than the solar panels can ever fill, and a battery that runs empty by eight every evening. Both a waste of money. Still unsure whether storage suits your situation at all? Read the comparison with or without a home battery first. What capacity costs and when it pays back is covered under what a home battery costs.

Capacity in kilowatt-hours tells you how much power fits in the battery. Power in kilowatts tells you how fast it can charge and discharge. Two batteries with the same capacity can therefore perform very differently on an evening of cooking, a running dryer and a car on the charger. We explain the difference between the two units under what is a kWh.

Why that power rating matters: during a peak the battery must actually be able to deliver. If it cannot, you still buy from the grid at the most expensive moment, while the battery sits there full. And if you want to charge during cheap hours, the charging power decides how much you can take in during that one cheap hour.

So look at the continuous charge and discharge power in the datasheet, not just the peak figure used in advertising. During the site survey we check that this power matches your consumption peaks and your connection.

Many existing homes have a single-phase connection; for newer or upgraded homes 3x25 amps is the standard. A home battery works fine on single phase, but its power shares that one phase with the rest of your house. A three-phase system can charge and discharge harder and spreads the load neatly across the three phases.

During the survey we look at your main fuse, the free circuits in the fuse box and where the inverter goes. Heavy systems or stacked modules quickly call for three phase. Upgrading the connection is possible, but above 3x25 amps your fixed grid charges also rise. We only include that in the advice when it genuinely pays.

For the location, the advice of the Dutch fire service (Dutch) applies: the most fire-safe spot is a cool, well-ventilated space such as the shed, otherwise the garage or the attic. Never hang the battery in your escape route, mount it on a non-combustible surface, fit a smoke detector in the same room and have the installation done only by a certified installer.

The fire service also advises checking the datasheet for qualification under the IEC-EN 62619 standard, and asking whether the battery management system shuts the battery down on a fault or rising temperature. Those are exactly the questions you are allowed to ask a seller.

From our own practice, three points come on top. Distance to the fuse box: long cable runs cost money and power. The surface: battery modules are heavy, so the wall or floor must carry them. And the environment: dry and frost-free, so no crawl space and not right next to the boiler. A full room-by-room walkthrough, from shed to attic, is under where to place a home battery.

The simplest battery charges on solar surplus and discharges as soon as your home needs more than the panels deliver. A fine base, every system starts there. It gets more interesting with an energy management system and a dynamic energy contract: the battery then charges during the cheapest hours and discharges when power is expensive, including in winter when the panels do little.

A battery that can be steered remotely can also join grid control: for a payment it helps the grid during peak moments. And if you want to genuinely trade with it, you need that combination of EMS and dynamic contract anyway; it is also the basis for the VAT refund on a home battery.

So when choosing, look beyond the box on the wall at what the software can do and which energy contracts it works with. A cheap battery without open control can end up costing you more than a smarter battery that moves with your contract.

Do not assume every home battery powers your house during an outage. Without a dedicated backup provision, a grid-connected system actually switches off during a power cut. If you do want backup, there are two flavours: hybrid backup keeps one or two circuits running, for example the fridge and your router, and a full backup system can take over the entire fuse box. The latter needs more space and budget.

Which variants we supply and how the switchover works is on the HYXi Power home battery page. Weigh up beforehand what an outage really costs you; for most households backup is comfort, for a home office or medical equipment it can weigh heavier.

A battery system with a power rating of 0.8 kilowatts or more must be registered, as stated by the Netherlands Enterprise Agency (RVO) (Dutch). You do that via Energieleveren.nl, the same portal where solar panels are registered. Grid operators use the registration to plan the grid per neighbourhood. Check in your quote who handles the registration, so the step does not slip through.

Also inform your insurer about the placement; that too is fire service advice. It prevents discussion about cover if anything ever happens, and tells you upfront whether your insurer sets requirements for the location or the installation.

During the site survey we look at your fuse box, your evening and night use from the meter data, the spot where the battery can hang and your wishes around control and backup. That produces an advice with capacity, power and configuration that fit your home, usually a system between 5 and 10 kWh.

You get a no-obligation quote within 24 hours, no deposit required, and after approval we usually install within three weeks. Want to talk it through first? Put your consumption to us or browse the options on our home battery page.