Lucent Technologies Lineage
®
2000 ECS Battery Plant J85500D-3
Issue 5 January 1999
Engineering, Planning and Ordering 3 - 7
service is another factor which will vary from application to
application.
Table 3-C lists reserve time practices which have been used in
some telecommunications applications where maintaining
power to the load is critical. The figures are not intended to be
guidelines except in the absence of any specified customer
The noise and transient filtering capability of batteries, however,
may also be considered in selecting the minimum battery
capacity. Many using systems specify the maximum allowable
input noise. Applications (such as UPS-supplied ac power)
which do not require batteries for dc reserve purposes may
require batteries or some other means for noise filtering.
Compare the input noise requirements of the using system to the
ECS Battery Plant specifications in Table 2-A.
Fill in the minimum reserve time below.
14. Minimum battery reserve time: ____ hours
Battery capacity is usually specified in terms of ampere-hours,
which is essentially a measure of energy. The ampere-hour
rating is the product of a constant discharge current and the time
to discharge a fully charged battery to a specified end voltage.
For comparison purposes, most vendors of telecommunications
batteries specify ampere-hour ratings at the 8-hour rate of
discharge to an end voltage of 1.75 volts per cell. Many battery
Table 3-C: Reserve Capacity
Backup Source
Typical Reserve Time
Attended
Location
Unattended
Location
Stationary Engine
(automatic start)
3 hours
3 hours +
travel time
Stationary Engine
(manual start)
4 hours
4 hours +
travel time
Portable Engine
4 hours + travel time
Uninterruptible
Power Supply
0 hours (batteryless)
