Safety check
Battery C-rate calculator
A battery must deliver the current your loads draw, not just store enough energy. The C-rate (load current ÷ capacity) tells you whether your draw is safe for the chemistry. Pull too hard, especially from lead-acid, and you lose capacity (Peukert effect), generate heat and shorten life.
Safe C-rates by chemistry
| Chemistry | Comfortable sustained rate | Notes |
|---|---|---|
| LiFePO4 / Li-ion | ~1C (often more) | Handles high continuous draw well; surge limited mainly by the BMS. |
| AGM / Gel | ~0.3C | Tolerates higher bursts than flooded, but sustained high draw shortens life. |
| Flooded lead-acid | ~0.2C | Above this the Peukert effect cuts usable capacity sharply and the bank runs hot. |
These are comfortable sustained limits, not hard cliffs — brief surges (a motor starting) are usually inverter-limited and last under a second. The real concern is continuous draw causing heat and capacity loss. If your continuous C-rate is too high, the fix is a larger bank (which lowers the rate) or a higher-current chemistry.
Educational estimate. See the methodology.