MG MGB User Manual

THE
ELECTRICAL SYSTEM
N
Recharging
from
an
external
source
The
length of
time
for
a
used battery
to
remain
on
charge
before
it
can
be
accepted
as
fully
charged depends entirely
on
the
speci■c
gravity
before charging
commences
and the
charging
rate.
The
charging
should
continue
at
5
amps.
until
all
cells
are
gassing
freely
and evenly
and
the‘specific
gravity
in
each
of the
six
cells has
reached
a
maximum, i.e.
has
shown
no
further
rise
in
four hours.
The
speci■c
gravity
at
the
end of charging
should be
within
the
limits
given
and
should
not
vary
.005
from
the values
given.
Do
not
allow the
temperature
of the electrolyte
to
exceed
the
maximum
permissible
temperature,
i.e.:
For
climates below
27°C.
(80°F.) 38°C.
(100°F.).
For
climates above
27°C.
(80°F.)
49°C. (120°F.).
If this
temperature
is
reached the charge
should be
suspended
to
allow the
temperature to
fall
at
least
6°
C.
(10°
F.),
otherwise
the life
of the
battery
will tend
to
be
shortened.
Refitting
The installation
of
the battery
is
a
reversal
of
the procedure
‘Removing’. Smear
the
terminal
posts
and
cable
connections
with
petroleum jelly and
tighten the
retaining
screws
suf■ciently
to
prevent
the cables
from
moving
on
the
terminal
posts
when
tested
by
hand, but do
not
overtighten.
NOTE—Whenever booster
charging
of
the battery
or
electric
welding
of the body
is
carried
out,
the battery
earth
lead
must
be
disconnected
to
prevent
damage
to
the
electrical
system.
Section N.2
PREPARING
DRY-CHARGED
BATTERIES
FOR
SERVICE
Dry-charged batteries
are
supplied
without
electrolyte but
with the plates
in
a
charged condition.
When they
are
required
for
service
it is
only
necessary
to
fill each cell with
sulphuric acid
of the
correct
specific
gravity.
No
initial
charging
is
required.
Preparing
electrolyte
The electrolyte
is
prepared by
mixing
together
distilled
water
and
concentrated
sulphuric acid, taking
the
precautions
given in
Section
N.3. The
speci■c
gravity
of
the
filling electrolyte
depends
on
the climate
in
which
the
battery
is
to
be
used.
Filling the battery
Carefully break
the seals
in
the cell
■lling holes and fill each
cell
with electrolyte
to
the
top
of the
separator
guards
in
MGB.
Issue
6. 5335
one
operation. The
temperature
of the ■lling
room,
battery,
and
electrolyte should
be maintained
between
16 and
38°
C.
(60
and
100°F.).
If the
battery has
been stored
in
a
cool
place
it
should
be allowed
to
warm up
to
room
temperature
before
■lling.
Putting
into
use
Measure
the
temperature
and speci■c
gravity
of
the
electrolyte
in
each of
the cells.
Allow
to
stand
for
20
minutes
and then
re-check. The battery
is
ready for
service
unless
the electrolyte
temperature
has
risen
by
more
than
5.5
0C.
(10°F.),
or
the specific
gravity
has fallen
by
more
than
10
points
(.010 S.G.).
In
this
event,
re-charge the
battery
at
the
normal re—charge
rate
until the specific
gravity remains
constant
for
three
successive
hourly
readings
and all cells
are
gassing
freely.
During the
charge
the
electrolyte
must
be
kept level with
the
top
of the
separator
guards by the
addition of distilled
water.
Section N.3
PREPARING
NEW, UNFILLED,
UNCHARGED
BATTERIES FOR
SERVICE
Preparing
electrolyte
Batteries
should
not
be ■lled
with acid until required
for
initial charging. Electrolyte
is
prepared by
mixing
distiller
water
and concentrated
sulphuric acid, usually
of
1.84(
SC. The
mixing
must
be
carried
out
either
in
a
lead-linec
tank
or
in
suitable
glass
or
earthenware vessels.
Slowly ad(
the acid
to
the
water,
stirring
with
a
glass
rod.
Never
add
the
water
to
the
acid,
as
the
resulting
chemical
reaction
causes
violent and dangerous
Spurting
of
the
concentrated
acid. The
approximate proportions
of
acid
and
water
are
indicated
in
the
following table:
Add
1
vol.
of
1.840
S.G. acid
to
distilled
water
as
below
To obtain
speci■c
gravity
(corrected
For climates
to
16°C.
(60°F.))
of
Below
27°C.
(80°F.)
1.260 3.2
volumes
of
water
Above
27°C.
(80°F.)
1.210 4.3
volumes of
water
Heat
is
produced
by
mixing
acid
and
water,
and the
electrolyte
should be allowed
to
cool
before taking
hydrometer
readings—unless
a
thermometer
is
used
to
measure
the actual
temperature
and
a
correction
applied
to
the readings
before
pouring
the electrolyte
into
the
battery.
Filling the battery
The
temperature
of the electrolyte, battery,
and filling
room
should be maintained between
16°
and
38°
C.
(60C
and
100°F.).
N.3

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English