Why is it crucial for all electrical loads and power sources to be turned off before connecting or disconnecting a battery?

It is crucial for all electrical loads and power sources to be turned off before connecting or disconnecting a battery to prevent a spark from igniting explosive gas. When a battery is connected or disconnected, the abrupt changes in electrical current can create sparks. Batteries, especially lead-acid batteries, can emit hydrogen gas during the charging process, which is highly flammable and poses a significant explosion risk if ignited by a spark. By ensuring that all electrical loads are off before interacting with the battery, the risk of generating sparks is minimized, thus maintaining safety for personnel and equipment.

While factors like battery longevity, voltage stability, and preventing system overload are important considerations in electrical systems, they do not address the immediate risks associated with handling batteries, particularly the potential for explosive gases and their ignition.