Lucent Technologies Lineage
®
2000 ECS Battery Plant H569-403
Issue 4 February 1997
Engineering, Planning, and Ordering 3 - 9
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
vendors also supply ratings at other discharge rates, such as 3-,
5- and 24-hour rates.
Although ampere-hour ratings are useful for rough estimates of
battery size, actual battery selection should be based on curves
or tables of discharge current versus time.
Charge Capacity
and Recharge
Time
For all but batteryless applications, rectifier capacity must be
provided specifically for the recharging of batteries. This
rectifier capacity must be engineered into the plant in addition to
that required to power the load under normal or float conditions.
The sum of the normal and the recharge rectifier capacities is
called the PLANT CHARGE CAPACITY.
The recharge current is a function of the recharge time and
voltage. For example, increasing the plant voltage will, within
limitations, decrease the necessary recharge time, but this calls
for more current. Increasing the plant voltage after a discharge is
also recommended by some battery vendors to assure that all
cells charge equally for maximum life. Although these two
charging methods are essentially the same, they are usually
called by different names. The former process is usually called
BOOST CHARGING, while the latter is called EQUALIZE
CHARGING. For the purposes of this manual, the term Equalize
is used to indicate boost or equalize charging. Refer to the
battery manufacturer's recommendations on equalize charging.
The recharging requirement is determined by customer practices
and is usually specified as a maximum time to reach a minimum
percent of full capacity, for example, at least 90% capacity in no
more than 24 hours.
o. Maximum recharge time: ____ hours
p. Percent of full capacity after recharge time (o): ____%
Refer to the Battery manual or other documentation to calculate
the required recharge current to meet the requirements of (o) and
(p). The recharge voltage (m) will be needed for this calculation.
q. Minimum recharge current: ____ amperes
