Battery bank, solar array, charge controller and inverter — calculated end to end, with the chemistry constants generic tools get wrong. No signup. Nothing stored.
Add your devices, set your conditions, and get a complete bill-of-system. Everything updates live.
Peak sun hours are approximate annual averages — verify against a local solar map for accuracy.
Estimates for planning. Verify with a meter and follow NEC / local code; have a licensed installer confirm before purchase or wiring.
The same daily load needs a very different bank depending on chemistry. That is why a single generic number is misleading — and why this tool sizes per chemistry.
| Chemistry | Usable DoD | Round-trip | Cycle life @ DoD | Cold tolerance |
|---|---|---|---|---|
| LiFePO4 | 80% | 96% | 3,000–6,000 | No charge <0°C |
| Li-ion (NMC) | 85% | 95% | 1,000–2,000 | No charge <0°C |
| AGM | 50% | 85% | 600–1,000 | Moderate |
| Gel | 50% | 85% | 500–1,000 | Moderate |
| Flooded lead-acid | 50% | 80% | ~1,200 | Sensitive |
Constants are drawn from manufacturer datasheets and NREL PVWatts derate guidance; see the methodology page. Educational sizing guidance, not an electrical design.