Fire Alarm Battery Connections Parallel vs. Series

Vary rarly in the industry will you connect fire alarm batteries in parallel since you are most likely using 12vdc batteries and most fire alarm systems are 24vdc.  Below is a description and some images of the differences between parallel and series connections.


Fire Alarm Battery Connections in Series:




The important things to note about batteries connected in series are: 1) the battery voltages add together to determine the fire alarm battery pack voltage. In this example the resulting pack voltage is 24 volts. 2) The capacity of the battery pack is the same as that of an individual fire alarm battery. This assumes that the capacities of the individual batteries are the same. In fact, this is a must. Do not mix and match different size batteries in the same battery pack.

Fire Alarm Battery Connections in Parallel:

The important things to note about a parallel connection are: 1) the fire alarm battery pack voltage is the same as the voltage of the individual fire alarm battery. This assumes that the individual battery voltages are the same. In fact, this is an absolute must. Do not mix and match different battery voltages in the same fire alarm battery pack. In this example the fire alarm battery pack voltage is 12 volts which is exactly the same as each of the individual 12-volt batteries. 2) The capacity of the battery pack is the sum of the capacities of the individual batteries. Again, make sure that all of the batteries are the same size that is that they have the same amp-hour capacity.