At standard temperature and pressure it is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas.

Since typical secondary batteries may give off hydrogen gas especially if overcharged, ventilation of a battery room is critical to maintain the concentration below the lower explosive limit.

The life span of secondary batteries is reduced at high temperature and the energy storage capacity is reduced at low temperature, so a battery room must have heating or cooling to maintain the proper temperature.

Batteries may contain large quantities of corrosive electrolytes such as sulfuric acid or potassium hydroxide. Materials of the battery room must resist corrosion and contain any accidental spills. Plant personnel must be protected from spilled electrolyte.

The lesson to pass on is that ventilation is critical in UPS battery rooms. Great care should be taken to ensure that the ventilation system is operational, and brings in enough outdoor air to properly ventilate the enclosure. .

Electrical safety interlocks should also be considered which would isolate the batteries from its power supply, not allowing the batteries to charge if the ventilation system isn't working properly.It is imperative that the battery room designers pay close attention to the design of ventilation systems and electrical safety interlocks. There are lots of good (and bad) ways to design and install battery rooms and critical ventilation systems. If designers do not have experience designing UPS battery rooms, experienced consultants should be contacted to ensure a safe and effective design.