Lack of adherence to a preventative maintenance schedule is one of the leading causes of failure of a backup power system. Regularly assessing the quality of battery packs and fuel is crucial for correct operation in the event of a disaster.
Similarly, it is important to test your generators at design load at least once every three years. Regularly “exercising” your standby generators at a fraction of the design load also plays a significant role in preventative maintenance of generators.
Maintenance requirements for generators are outlined in NFPA 110: Standard for Emergency and Standby Power Systems.