In general, why are nickel-cadmium storage batteries superior to lead-acid batteries?

Correct Answer: Option A — they can remain idle and keep a full charge for a long time

Nickel-cadmium batteries exhibit a very low internal self-discharge rate, allowing them to remain idle for extended periods while retaining a high percentage of their full charge. This characteristic makes them exceptionally reliable for emergency backup applications governed by 46 CFR Subchapter J and IEEE 45 standards.