Work out parallel battery capacity instantly with clear inputs, formula shown and shareable results.
Parallel strings add capacity and current capability while the voltage stays the same. The practical limit is circulating current: strings must be matched in age, chemistry and cable length, or the healthier strings will charge the weaker ones and waste energy as heat.
Parallel bank
Ah total = strings x Ah per string; voltage unchanged; max current = strings x per-string limit
Electrical results are planning estimates only. Verify against the applicable wiring rules (IEC 60364, BS 7671, NEC or local code) and have all installation work designed and checked by a qualified electrician.
Manufacturers usually recommend no more than three or four for lead-acid. Lithium packs with a shared BMS can go further if the interconnects are symmetric.
Unequal resistance makes the strings share current unevenly, so one ages faster and the imbalance grows.