Page 606 - Battery Reference Book

Nickel-cadmium secondary batteries 56/43
.-.. McGraw Edison
-
-
W
P 1.80
> This company produces three ranges of batteries:
;
1.70
- 1.60 The CED range for low-rate discharge applications
5 1.50
.- c" 1.40 such as communications standby systems.
1.30 The ED and MED ranges for medium-rate dis-
E 0 1 2 3 4 5 6 7 8 charges in applications, respectively, such as rail-
way signalling, communications, rail transit (ED)
and switch gear power operations (MED).
Figure 51.3'1 Typical constant current charge characteristics. The HED range for high-rate discharge applications
Charging rate 0.2125 A at 25°C (Courtesy of Nife Jungner)
such as engine/turbine starting.
Typical discharge performance data for some of All the batteries in these ranges have a nominal voit-
the Nife range is shown in Table 51.49 (to 1.14V age of 1.2 Vkell. The charging voltages on float charge
end-voltage per cell) and Table 51.50 (to 0.83V end- and high-rate charge, respectively, are 1.42- 1.47 and
voltage per cell). 1.52- 1.60 V/cell and operating temperatures are in the
The tabulated discharge performance data and the range -40 to 45°C.
rated capacities are velid for fully charged cells. For The CED range is used for communications,
all cell types the rated capacity Cs is defined as avail- telecommunications, security and fire alarm systems,
able ampere hours at 5 h discharge to an end-voltage and low power control loads with long time periods.
of 1 .O V/cell. The rated capacity is no measure of per- The electrical characteristics of this range are presented
formance. The performance depends on the battery in Tables 51.52 and 51.53.
construction. For example, an H-type cell at 15min The ED range is used for railway signalling, com-
discharge can deliver about twice the discharge current munications and rail transit applications. The elec-
compared to an L-type cell of equal rated capacity. trical characteristics of this range are presented in
It is therefore advisable to use the discharge perf'or- Table 51.54.
mance tables to find the proper H, M and L type The MED range is used for unintenvpted power
alternatives for a specific application. The final choice
of cell type should be made by comparison of prices, systems, higWlow-rate duties, switchgear tripping and
closing, emergency lighting power systems and solar
dimensions, etc. applications. The electrical characteristics of this range
Typical discharge performance curves for the three
types of batter,y are shown in Figure 51.32. are presented in Tables 51.55 and 51.56.
The HED range is used for engine starting, control
power, uninterrupted power supply, switchgear trip-
Varta ping and closing, and pump and solenoid operation.
Varta produce a range of vented nickel-cadmium The electrical characteristics of this range are presented
stationary batteries designed for areas of application in Tables 51.57-51.59.
with special operation conditions such as:
1. Ambient temperatures between 0 and -40°C. FRIWO (West Germany)
2. Danger of deep discharge.
3. High mechanical stresses. This company manufactures two ranges. The TRP
4. Limited space availability. or HWHKP range is designed for normal discharge
5. Possibility of being taken out of service. currents, i.e. capacity discharge of more than 1 h up to
3 h. The TS/TSP range is designed for high currents,
They produce two ranges of batteries, the Special i.e. a discharge of 1 h or less.
X and the Special M range, which differ from one Each range has its advantages within its application
another in the construction of the electrodes used. limits. The T/TP and HWHKP ranges offer a maxi-
The Special X range is for application with extreme mum capacity at low volume and low weight, whereas
electrical and physical conditions, and for peak current the TS/TSP range provides high-current short period
loads in the seconds and minutes ranges. At ambient discharges.
temperatures of -2O"C, these batteries yield 90% of The design features of the TS/TSP range are:
their rated capacity.
The Special M range is for areas of application with 1. Compared with the T/TP or HK/HKP ranges, a
battery bridging periods between 30 min and several 30% increase in plates resulting in increased active
hours. material surface.
The electrical characteristics of the product range 2. Pin separators instead of corrugated perforated PVC
available from Varta are shown in Table 51.51. separators.