To keep emergency lead-acid batteries in a full state of charge for emergency use, what is normally done?

Correct Answer: Option B — Batteries are kept charged by maintaining a continuous trickle charge.

Emergency and reserve storage batteries must remain fully charged and ready for immediate service. IEEE 45 and 46 CFR recommend maintaining a continuous, low-rate trickle charge to counteract natural self-discharge without overheating or overcharging the plates.