Page 627 - Battery Reference Book

51/56 Nickel batteries

compact blocks, portable blocks and in open wooden
crates. Alternatively, they can be delivered in enclosed
wooden crates or in steel containers. Types TS and > I
TSP are specially designed for high-rate discharges - 16- I
+d P 15-
and for use as starting batteries, i.e. for discharges - I I I I I 1 I
I
from less than 1 h down to short-time discharges and 9 14- I I I I
I
high-ratehmpulse loads with favourable voltage perfor- 13 - I I I I I 1 +-
I
mance. They can be used for charge/discharge opera- 12 - I I M
tion, switch-tripping operation and standby parallel 11 -18OC I I
I
operation as well as for stabilizing operation. 10 k Final discharge voltage
--+ ----- +--
7------
They can be charged with high charging currents 9- t- 1 I-;
1-
within a short period of time. At low temperatures 5 s res: 5 s rest
they provide favourable capacity characteristics. Deep 8- I I I I I I I I I I
discharges have no effect on the capacity.
Discharge data on types TS and TSP are given in
Table 51.62.
51.1.4 Aircraft batteries - :"F
Another major application of vented nickel-cadmium
batteries is aircraft batteries. These batteries are
equipped with a battery temperature monitoring facility 2 13
in order to comply with the requirements of the
FAA. One or more thermal switches are installed in
the battery to give advance warning and to prevent
overheating of the battery, thereby achieving a greater i 10
safety of flight operation. 9,
The thermal switches are connected to a connector
on the battery container from which a cable leads to a -
warning lamp situated on the instrument panel of the
aircraft. 1400 - 6- \
This warning lamp lights up when the predetermined - 5 - \ Capacity extracted = 18.70 A h
temperature limit for the thermal switch is reached, e.g. - 1300
U
I
65°C. When the warning lamp lights up, charging of 1200- 4-
the battery must be stopped. When the battery is cooled W 3-
=, 1100-
0 -
1000 2-
900 - 1- I I 845 A 1 I I
q Figure 51.36 Varta vented nickel-cadmium battery type F20/40HI
- 0
I
800
(24V, 40Ah): effect of initial load on battery voltage at -12.2%
(Courtesy of Varta)
down the warning lamp goes out and the battery is
ready for service.
Technical data on several of the Varta range of
-
12
aircraft batteries are given in Table 51.63. Typical
discharge data are given in Figures 51.34-51.36.
The effect of battery temperature in the range -30
10 to +3WC on discharge performance is shown in
8
0 Figure 51.37.
0 16-50 300 400 500 600 700 Eagle Picher produce the VNC range of batteries for
Current (A) aircraft starting, aircraft emergency power and ground
power units. Capacities up to 120 Ah are available (see
Figure 51.34 Varta vented nickel-cadmium battery type HI:
dependence of initial voltage on current and temperature (Cour- selected examples in Table 51.64). Cycling lives in
tesy of Varta) excess of 5 years or 1000 cycles are claimed for these