A comparison between battery disconnection and load disconnection at low voltage to prevent over-discharging of valve regulated batteries

With the introduction of valve-regulated battery power supplies in telecommunication systems, new demands on the handling of batteries at low voltages have resulted. In order to avoid the risk of destruction of these batteries, they need to be protected against overdischarge, e.g. during a mains failure. This paper describes two main methods of protecting the batteries: battery disconnection; and load disconnection. Also concluded in the paper are availability calculations and a cost comparison between the two methods