Page 396 - Battery Reference Book

Silver-zinc secondary batteries 34/3
34.1 Silver-zinc primary batteries in proportion to load, but holds constant throughout
the useful section of the discharge curve. Shelf life
This type of battery is available from several suppli- is several times longer than for ordinary dry cells at
ers. Vata, for example, produce a range of 1.55V room temperature. However, the cells should not be
silver-zinc cells in the capacity range 45-175 mA h stored below 0°C. Shelf life is 6 months under correct
and a 6V battery of capacity 170mAh (Table 34.1). storage conditions and this may be extended by cold
These are used mainly in calculators, hearing-aids and storage.
photographic applications.
Varta also produce a range of 1.5 V low-drain sil-
ver-zinc cells for electric and electronic watches
with analogue or LCD display in the capacity range 34.2 Silver-zinc secondary batteries
50- 180 mA h; and 1.5 V silver-zinc high-drain cells in
the 38- 190 mA h capacity range for use in solid-state Some, now commonplace, applications for silver-zinc
watches with LED or LCD display with backlight. batteries are:
Silver-zinc batteries are used, in addition, in pho- 1. Television and broadcasting Electronic news
toelectric exposure devices, flashlights, instruments, gathering cameras, video tape recorders, portable
reference voltage sources and missile telemetry, space lighting.
launch vehicles, aerospace, portable equipment and 2. Portable industrial instrumentation Ultrasonic
military applications. detectors, portable court recorders, portable ther-
Other suppliers (Eable Picher, Silberkraft) pro- mocouple sensors, portable inventory devices,
duce remotely activated silver-zinc batteries for portable methane detectors, portable miners’
applications such as torpedoes, rockets, missiles and lamps, portable crane control, portable oxy-
pyrotechnic devices, ignition and fuse applications, and gen mask testers, portable underground radios,
emergency standby batteries. portable floodlights, portable measuring and con-
Eagle Picher supply gas-generating pyrotechnic
devices, which can be used for the activation of trol instrument converters, emergency power sup-
ply of data-processing machines, flash and film
remotely activ,ated batteries by transferring electrolyte lights in cameras.
from a reservoir to the battery cells. Eagle Picher have
developed over 70 gas-generator configurations with 3. Medical instrumentation Portable ambulance
capabilities ranging from 20 to 200 000 cm3 (standard emergency transceivers, heart action recorders,
condition gas output), many of which have been used portable organ transfer and storage devices, physi-
in a majority of missile/spacecraft systems. cians’ hand-held examining lights, portable cysto-
The Chloride of Silver Dry Cell Battery Co. of scopes, portable emergency operating-room light-
Baltimore supply a silver-zinc battery with a mild ing, portable defibrillators.
acid electrolybe containing silver chloride as a depol- 4. Oil and gas pipeline and exploration Power for
arizer. This battery is recommended as a power unit in instrumentation for examination devices, under-
test instruments such as blasting galvanometers, circuit water sleds for external pipeline and drilling
testers, volt-ohmmeters and clocks. Multi-cell batteries rig base examination, down-hole instrumentation
for B-voltages and bias are available for use in elec- power, heated diving suits.
tronic circuits, electromedical instruments and other 5. Oceanographic exploration Commercial sub-
specialized lowdrain uses where constant voltage and mersibles, underwater seabed surface mining
long life are important. The battery has an open-circuit devices, underwater lighting portable cameras,
voltage of 1.05 V. Under load, terminal voltage drops buoys.

Table 34.1 Silver-zinc cells and batteries supplied by Varta

Varta Voltage Internal Dimensions IEC Main Vavta
type (VI resistance reference application order
No. (Q2) Wei ht NO.
-~ (g5
v 8 GS 1.55 45 20.0 11.6 2.1 0.9 - Calculators 4173
V 13 HS 1.55 75 4.2-6 7.9 5.4 1.1 SR 48 Hearing-aids 4012
V 10 GS 1.55 85 10.0 11.6 3.1 1.4 - Calculators 4174
V41 HS 1.55 120 3.2-5 11.6 4.2 1.8 SR 43 Hearing-aids 4041
v 12 GS 1.55 130 6.0 11.6 4.2 1.9 SR 43 Calculators 4178
V 76 IHS 1.55 175 3.5-5 11.6 5.4 2.4 SR 44 Hearing-aids 4076
V 76 PX 1.55 175 3.5-5 11.6 5.4 2.4 SR 44 Photography 4075
V 13 GS 1.55 175 3.5-5 11.6 5.4 2.4 SR 44 Calculators 4176
V 28 IPX 6.00 170 15.0-22 13.0 25.8 12.8 - Photography 4028