Service batteries

Required power [W] Required time of service [h]

Battery capacity: [Ah]

Rated voltage: Type of battery:
24 V Lead-acid of large surface caonstruction
12 V Lead-acid with latticed structure plates
Alkaline
Alkaline with low internal resistance
Temperature of electrolyte:
25 °C, batteries placed on board of ships sailing in the tropical zone,
15 °C, batteries fitted on board of ships sailing in unrestricted zone,
5 °C, batteries fitted on board of ships sailing in unrestricted zone or operated in moderate zone and installed in the engine room or compartments to heated by adjacent rooms,
-15 °C, batteries fitted on board of ships sailing in unrestricted zone or operated in moderate zone and installed in non-heated rooms,
-25 °C, batteries fitted on open decks on ships other than sailing only in the tropical zone.
Temperature coefficient, a= , assumed:
Discharging time coefficient, b= , assumed:

Calculations were carried out based on the Polish standard PN-W-89509:1997 Merchant ships, batteries, selection, in accordance with the following equation: aku_service_wzor, where P - power [W], t - time [h], Un - rated voltage[V], a - temperature coefficient (curves are available in the standard) taking into account reduction of the capacity due to electrolyte temperature, b - time coefficient (curves are available in the standard) taking into account reduction of the capacity in time.   Author: Daniel Czarkowski