9
STORAGE The lamp should be stored in a fully charged condition with
the housing closed securely. An ideal storage temperature is
between 15 and 25°C, (60 and 75°F). Under no
circumstances should the lamp be subjected to temperatures
above 45°C, (110°F).
The rechargeable cells will slowly discharge when not in use,
(depending on the ambient temperature up to 60% discharge
in one month!). We recommend therefore that the cells be
charged approximately once a month when the lamp is not in
use.
For extended periods of storage, the power pack should be
removed from the housing and stored separately in a suitable
cool dry place, (see preparation for charging page 10).
Regularly check the cells for signs of corrosion or gas
leakage, (the protective skin showing signs of bubbling,
floury or white residue between the cells or in the housing,
corrosion around the charging socket.) Should you discover
signs of leakage or corrosion, return the lamp immediately to
the manufacturer.
CHARGING INTRODUCTION IN THE CHARGING OF NICKEL CADMIUM CELLS
Nickel Cadmium cells are generally described as being gas
and acid sealed cells. The position of the cells during the
charging process is therefore irrelevant as no electrolyte can
escape. There is however no supplier of cells that will
guarantee this feature for the entire life of the cells! During
the charging or discharging process, the cells may produce
an over pressure inside, opening the integrated over pressure
relief valve. Should this occur, the electrolyte, or Hydrogen
can escape from the cells. Because the electrolyte is a very
aggressive acid, and additionally conducts electricity, this
may lead to the galvanic corrosion of the cells, and a
destruction as a result of the contact with the acid. The
escaping hydrogen can combine with oxygen in the air and
form a highly explosive gas. A single cell the size of a
standard D cell battery can produce up to 25 litres, (1 cu ft)
of gas! It is for this reason that nickel cadmium cells should
always be removed from a housing before they are
recharged. Only then is the safe use and longest possible life
of the cells guaranteed.
MEMORY EFFECT
The so called Memory Effect is the common term for the
reduction in the capacity of the cells as a result of charging
the cells in a partially discharged condition. (e.g. A wireless
telephone hand set has a battery life of 24 hours, but is
replaced on the station and therefore charged after 3 hours).
The common technique for overcoming this is to fully
