What are the two allowed types of charging methods for battery backups in a fire alarm system?

The correct answer highlights two commonly accepted charging methods for battery backups in fire alarm systems: trickle charge and float charge.

Trickle charging is a method where the battery is charged at a rate that maintains its full capacity without overcharging. This is particularly useful for keeping lead-acid batteries topped off while they are in a standby condition. In fire alarm systems, which are expected to be reliable and operational at all times, trickle charging ensures that batteries are consistently ready when needed.

Float charging, on the other hand, maintains the battery at a constant voltage, ensuring that the battery is kept at a fully charged state without the risk of overcharging. This method is often employed in applications like fire alarm systems where the power supply might not be constant, and the batteries need to remain ready to provide power during an emergency.

The other choices include methods like boost charge, solar charge, rapid charge, and pulse charge, which are less commonly used in the context of battery backups for fire alarm systems. These methods may either involve higher charging rates or might be specific to particular types of rechargeable batteries, making them less suitable or effective in ensuring continuous reliability for fire alarm systems. Thus, trickle charge and float charge are the preferred methods, maintaining performance and