Page 213 - Battery Reference Book

Magnesium-cuprous chloride batteries l7/3
There are three main types of water-activated battery: discharge time. McMurdo also supply a range of Aqua-
magnesium-s ilver chloride, zinc- silver chloride and cells for life-rafts and life-jackets (Table 17. I).
magnesium-cuprous chloride. These batteries are all Magnesium-silver chloride batteries have an energy
activated by water or seawater and have obvious density of 30-120Wh/kg, 40-250Wh/dm3 and a
applications in marine and aircraft safety lights, buoys power density of 1200 W kg between -20 and +60"C,
and flashing beacons, military power systems, commun- and cells up to 150kW are obtainable. Designs in the
ications and portable electronic devices, sonobuoys, range 1-250 V are available.
torpedoes, flares, mines, pingers, balloons and life-
jackets. These batteries have a long storage life pro-
vided they are kept in a sealed condition. Once 17.2 Zinc-silver chloride batt
unsealed and immersed in water they must be con- These cells have similar applications to those of
sidered expended. They cannot be recharged. magnesium-silver chloride batteries. They have an
energy density of 15-60 W hikg (power density
100 W kg) and 20- 150 W h/dm3 (volumetric power
Magnesium-silver chloride density 2400 W dm3). Operating temperatures are
batteries between -30 and +60°C, and cells up to 2500W

Durations are between several seconds and 20 days for are available from SAFT. These cells are water or
seawater activated. and have a long dry shelf life, high
magnesium-silver chloride batteries. An example of
this type of cell is the L18A diver's underwater search- performance and a long discharge time capability at
light battery supplied by McMurdo Instruments Ltd low rates (up to 300 days). Designs are available in
(Aquacells). This cell is 103 x 35 x 25mm, weighs the 1-50V range.
95 g and has an output of 4 V for 1.5 h at a 1 A load-
ing. The L37 submarine escape hatch lighting battery 17.3 Magnesium-cuprous chloride
is a 24 V emergency supply system which is designed batteries
to operate at pressures up to 2756kPa. The battery
is 305 x 254 x 72mm, weighs 6.6kg and will oper- These cells have a similar energy density (20-98
ate two 24-V 36-W lamps for 8h. The L43H dis- Whkg and 10-150Wh/dm3) and operate in the
tress beacon (13.5V) battery for ships and aircraft temperature range -20 to +60"C. They are available
is 175 x 51 x 125mm, weighs llOg and has a 90h with up to 50 W output and in the 1-10OV range.

Table 17.1 Magnesium-silver chloride cells for life-jackets and life-rafts available from McMurdo Instruments
Designation Application Dimensions Weight Power output Duration
(mm) (g) @)
L8.1 Life-jacket 93 x 26 x 12 34 1.5 V, 0.3 W 8
M8M Life-jacket 93 x 26 x 12 34 lSV, 0.165 W 20
or 1.5V, 0.25W 14
L12B Life-jacket 110 x 30 x 22 80 3v, 1W 12
and life-rafi or 3 V, 0.25 W 24
L50 Life-raft 117 x 66 x 36 120 3 V, 0.5 W 12