Stored kilowatt-hours only pay back if the house uses them at night
A home battery stores what a balcony or roof array makes during the day so the house can use it in the evening, and the arithmetic that decides whether it is worth buying is simple and rarely printed on the box. Usable capacity is not nameplate capacity: the reserve a battery keeps for its own protection and the round-trip losses of charging and discharging both come off the top, and the makers that publish a usable figure separately are the ones worth comparing. Charge and discharge power in watts decides whether the battery can absorb a midday peak and cover an evening cooking load; a large capacity behind a small inverter fills slowly and empties slowly. Chemistry is almost always LiFePO4 on this shelf, and the cycle count is again only readable with the capacity percentage attached to it. Compatibility is the part that catches people out: a battery designed for one micro-inverter ecosystem may not talk to another, and the metering that tells the system when the house is exporting is either included, sold separately, or absent. Installation rules differ by country and by building, and they come from the maker’s documentation and the local regulations, not from a comparison page. We compare usable capacity, charge and discharge power, chemistry, cycle life, inverter compatibility and published metering.
2240 Wh nominal · LiFePO4, 6000 cycles · expandable · IP65 · AC-coupled via a micro-inverter · smart meter optional
A 2240 Wh LiFePO4 balcony storage unit rated IP65, coupled through a micro-inverter, expandable, and installed without an electrician according to its listing.
Best for: A balcony installation that already has a micro-inverter and wants storage added without rewiring.
≈ €311
1600 Wh base, up to 8 kWh · 1600 W output · 3 MPPT, 2700 Wp solar · LiFePO4 · IP65 · AC-coupled · smart meter and tariff integration
An AC-coupled all-in-one balcony storage system with three MPPT trackers taking 2700 Wp, a 1600 W output, expansion to four packs, and integration with dynamic electricity pricing.
Best for: A household on a dynamic electricity tariff that already has roof PV and wants to stop exporting surplus.
≈ €448
1.92 kWh nominal · 2800 W solar across 4 MPPT · 1200–2300 W on two AC ports · LFP, 6000 cycles · IP65 · down to −20 °C · 26 cm wide
An AC-coupled 1.92 kWh LFP unit with four MPPT trackers taking 2800 W of solar, two mains ports rated 1200 to 2300 W, IP65 and stated operation to −20 °C.
Best for: A narrow indoor space beside an existing balcony installation, where four panel groups need managing separately.
≈ €549
1.92 kWh nominal, up to 11.52 kWh · AC-coupled · bidirectional DC/AC efficiency 96.5 % · AC round-trip efficiency 86 % · app control
An AC-coupled 1.92 kWh battery expandable to 11.52 kWh whose listing publishes both a conversion efficiency and a round-trip efficiency — the only one in this family that does.
Best for: Someone comparing storage on what a stored kilowatt-hour costs rather than on headline capacity.
≈ €545
1600 Wh base, expandable to 9.6 kWh · 2 MPPT, 1200 W solar (600 W per tracker) · 6000 cycles · IP65 · down to −20 °C · 10-year warranty
A balcony storage unit with two MPPT trackers taking 1200 W of solar, expandable to 9.6 kWh with five further packs, rated IP65 and stated to operate down to −20 °C.
Best for: A balcony with panels facing two different directions, where per-tracker limits matter more than total capacity.
≈ €399
2.048 kWh nominal · IP66 · stackable to 4 modules · WiFi and Bluetooth · for Growatt balcony systems
A 2.048 kWh balcony battery rated IP66 that stacks to four modules, carries WiFi and Bluetooth, and is sold as a companion to a Growatt balcony system.
Best for: An existing Growatt balcony installation whose owner wants storage from the same maker.
≈ €388
7.2 kWh nominal, up to 12 kWh · 2400 W charge and discharge, limitable to 800 W · LiFePO4 · −20 °C to +55 °C · IP65 · backup socket · smart meter included
A 7.2 kWh AC-coupled system supplied with a Pro 3EM smart meter, rated 2400 W in both directions with an 800 W limit available, and carrying a backup socket for outages.
Best for: An existing roof installation whose owner wants to stop exporting and keep a few circuits alive through an outage.
≈ €1535
A price quoted in the text of a PowerVerdict page dates from the day that page was written; the live figure beside each product is fetched while you read and replaces it.
