The starting point
The right battery is the one that can cover a useful part of your demand and recharge often enough to justify its cost. Capacity in kWh and output in kW answer different questions.
Give the battery a clear job
Decide whether your priority is using more daytime solar, reducing expensive imports or keeping an outage reserve. Write down the priority before comparing products.
A system intended for daily bill savings can have a different operating schedule from one that keeps a large reserve for power cuts.
Compare more than the headline capacity
Request usable capacity, charge and discharge power, operating limits, warranty conditions and the scope of any backup equipment. Ask the installer to identify the figures that apply to the complete proposed system.
Our recommended quote comparison keeps the panels and tariff fixed while changing the battery. That makes the additional storage cost and benefit easier to see.
A useful starting question
How much electricity does the home use between useful charging opportunities? That question is more informative than choosing a battery from the number of bedrooms alone.
- Separate routine consumption from occasional heavy loads.
- Account for planned EV charging without double counting.
- Keep a record of the reserve you want available.