Size on night consumption, not the bill total
The number that matters is how much energy the house uses when the panels are not producing.
A household using 900 kWh a month does not need a 30 kWh battery. Most of that energy is consumed during the day, often while the roof is producing. What the battery has to cover is the evening and night load — lighting, cooking, air conditioning, hot water — plus whatever the owner wants to keep running during an outage.
Two practical ways to get the figure. Read the evening-to-morning consumption from a smart meter, or take the daily average and apply the share that falls after sunset, which for a typical household is 40–60%. Both give a first-pass number that is far closer than sizing on the monthly total.
The four inputs that decide the model
Everything else is detail.
- Night consumption (kWh) — sets the minimum capacity. Add 10–20% margin for degradation and cold weather.
- Backup loads (kW) and hours — a fridge, lights, internet and a few sockets are a very different requirement from whole-house air conditioning. This decides the inverter, not just the battery.
- PV size and orientation — a battery that cannot be refilled by the roof is a battery that cycles from the grid, which changes the economics.
- Inverter DC input limit — every hybrid inverter has a maximum battery capacity and voltage window. Exceeding it is a warranty and safety problem, not a performance one.
Wall-mount or floor-standing
Same chemistry, different room requirements.
| Model | Capacity | Voltage | Parallel | Warranty |
|---|---|---|---|---|
| GWR 48-100 (wall-mount) | 5.12 kWh (100 Ah) | 51.2 V SELV | — | 5 years |
| GWR 48-200 (wall-mount) | 10.24 kWh (200 Ah) | 51.2 V SELV | — | 5 years |
| GVR series (floor-standing) | 15.36–32.15 kWh | 51.2 Vdc | Up to 15 units | 5 years |
Wall-mount suits apartments, villas and retrofit where floor space is scarce and the capacity need is modest. The 5.12 kWh unit covers a small flat's night load; the 10.24 kWh unit is the usual choice for a family home with air conditioning.
Floor-standing takes more room but scales: the 15.36–32.15 kWh tower range is stackable and can be paralleled up to 15 units, which is what larger homes, small off-grid cabins and multi-tenant buildings need. The SELV 51.2 V platform keeps the DC side in the low-voltage band, which simplifies installation requirements in many markets.
Chemistry, safety and documentation
The part that should be identical whoever you buy from.
LiFePO4 is the default for home storage because its thermal behaviour is more forgiving than NMC and its cycle life is longer. Our packs are supplied with IEC 62619 and UN38.3 test documentation, carry CE and RoHS marking, and are manufactured under ISO 9001 and ISO 14001 certified systems.
Two installation details decide whether the warranty survives: ventilation and clearance around the unit, and whether the battery is installed inside the thermal envelope or in an unheated garage. A pack rated for a comfortable temperature range will not deliver its rated capacity in a freezing outbuilding, and no warranty document changes that physics.
Home battery sizing FAQ
How many kWh does a normal house need?
Usually 5–10 kWh for a flat or a well-insulated home, and 10–20 kWh where air conditioning or electric heating dominates. The right answer comes from the evening consumption figure, not from the floor area.
Can I add capacity later?
On the tower (GVR) range yes — modules stack and units parallel, up to 15. On wall-mount models the capacity is fixed, so oversizing slightly at the start is usually cheaper than replacing later.
Does the battery work with my existing inverter?
It works with 51.2 V hybrid inverters that support the pack's voltage window and BMS protocol. Send the inverter model and we will confirm compatibility before you order.
What is the difference between kWh and Ah on the datasheet?
Capacity in Ah is multiplied by the nominal voltage to give kWh: 100 Ah at 51.2 V is 5.12 kWh. Comparing batteries by Ah alone across different voltages is meaningless.
Can the battery be installed outdoors?
Only in a sheltered location within the rated ambient range. Direct sun, frost and humidity all shorten life; an indoor wall or a ventilated utility room is the better default.
Plan a home storage project with us.
Send the night consumption, the backup loads and the inverter model. You get a model recommendation and a compatibility check before any quotation.
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