A battery is useful only if it can serve a real need in your setup. Capacity alone does not tell you whether it will work—or pay for itself.
Start with the equipment you already own
- Find the panel and inverter model numbers and their manuals.
- Identify whether the proposed battery connects on the DC side or has a separate AC inverter.
- Look for the manufacturer's documented system combinations, voltage and current limits, output controls and regional use conditions.
- Verify certification for the actual product or system, not just a component or a similarly named overseas model.
A certification framework describes how equipment may be evaluated. It does not prove that a particular combination has passed that evaluation.
Compare extra savings with extra cost
If you have already paid for the solar setup, treat that as a past cost. In retrofit mode, the calculator compares a battery with the same solar setup without storage. Include the battery, adapters, controller, required metering, fitting and taxes in the added cost.
Do not give the battery credit for savings the panels would have produced anyway.
When a battery is less likely to help
- You already use most solar output while it is being generated.
- Shade or a small array leaves little energy to store.
- The battery has substantial continuous power consumption.
- The full added cost exceeds the extra value over your expected ownership period.
When this calculator is the wrong model
It represents DC-coupled storage sharing one AC output limit. It does not model separate AC batteries, time-of-use arbitrage, demand charges, emergency backup or an off-grid power station. Outage operation depends on the equipment and approved system design.
Before installation, check the current state rules, utility requirements, property permissions and the actual equipment documentation.