Service battery capacity

Calculations follow the Polish standard PN-W-89509:1997 — Merchant ships, batteries, selection, in accordance with the following equation.

• P — power [W]
• t — time [h]
• Uₙ — rated voltage [V]
• a — temperature coefficient (curves in the standard), reduction of capacity due to electrolyte temperature
• b — time coefficient (curves in the standard), reduction of capacity over time

This page is reference only: coefficients a and b come from curves in the standard rather than a closed-form equation, so no interactive calculator is provided here.