. Once the active chemicals are
exhausted, the cell must discarded.
Once the active chemicals are
exhausted, the cell must discarded.
Definition
A primary cell cannot recharged.
Mercury primary cells have emf 1.
Negative
connecting bar
Positive
connecting bar
All plates
deeply
ribbed Negative plate
Separator
Positive plate
FIGURE 14. the cell is
connected suitable electrical supply, electrical energy stored the
plates the cell chemical energy. Thus, supply can
be provided connecting four cells series. The batteries contained within these units should replaced about
every years, recommended the manufacturer. Figure 14.
Primary cells
A primary cell cannot recharged.
Secondary cells
A secondary cell has the advantage being rechargeable.61 shows the construction lead-acid battery.5V.61
The construction lead-acid battery.
A record should kept each item equipment and the date each
test qualified responsible person. After testing, the
emergency system must carefully restored its normal operative state.Basic Electrical Installation Work
342
The British Standard recommends that the full load should carried by
the emergency supply for least every months. Primary cells, the form Leclanche cells, are used extensively por-
table power sources for radios and torches and have emf 1.
Self-contained units are suitable for small installations about 12
units.
A lead-acid cell secondary cell. Each cell delivers about 2V, and when
six cells are connected series 12V battery formed the type used on
motor vehicles.
Definition
A secondary cell has the advantage of
being rechargeable. Larger
voltages are achieved connecting cells series. may necessary produce
the record evidence satisfactory compliance with statutory legislation
to duly authorized person. They have long shelf life and leakproof
construction, and are used watches and hearing aids.35V, and can have very large
capacity small physical size. the cell con-
nected suitable electrical sup-
ply, electrical energy stored the
plates the cell chemical energy. When the cell connected load,
the chemical energy converted electrical energy
