Fig
.1.
Electrical
system
static
current
draw
being
measured
.
To
determine
the
circuit
or
component
causing
the
problem,
remove
one
Puse
at
a
time
until
the
current
drops
to
a
normal
range
.
BATTERY
SERVICE
The
E36
uses
a
six-cell,
12-volt
leadacid
battery
mounted
in
the
luggage
compartment
.
See
Fig
.
2
.
NOTE-
E36
convertible
models
require
a
specialbattery
which
is
designed
for
constant
vibratfon
.
A
battery
not
de-signed
for
this
will
fail
much
earlier
.
Battery
capacity
is
determined
by
the
amount
of
current
needed
tostart
the
vehicle,
and
by
the
amount
of
current
con-
sumed
by
the
electrical
system
.
BMW
batteries
are
rated
by
ampere/hours
(Ah)
and
cold
cranking
amps
(CCA)
rating
.
The
Ah
rating
is
determined
by
the
average
amount
of
current
the
battery
can
deliver
over
time
without
dropping
below
a
specified
voltage
.
The
CCA
is
determined
by
the
battery's
ability
to
deliver
starting
current
at
0°
F
(-18°
C)
without
dropping
below
a
specified
voltage
.
Battery
Testing
noN~A
B9517
Battery
testing
determines
the
state
of
battery
charge
.
On
conventional
or
low-maintenance
batteries
the
most
common
method
of
testing
the
battery
is
that
of
checking
the
specific
gravity
of
the
electrolyte
using
a
hydrometer
.
Before
testing
the
battery,
check
that
the
cables
are
tight
and
free
of
corro-
sion
.
See
Fig
.
2
.
Hydrometer
Testing
The
hydrometer
consists
of
a
glass
cylinder
with
a
freely
moving
float
inside
.
When
electrolyte
is
drawn
into
the
cylin-
der,
the
levelto
which
the
float
sinks
indicates
the
specific
BATTERY,
STARTER,
ALTERNATOR
121-
3
Fig
.
2
.
Battery
in
right
sideof
luggage
compartment
.
gravity
of
the
electrolyte
.
The
more
dense
the
concentration
of
sulfuric
acid
in
the
electrolyte,
the
less
the
float
will
sink,
result-
ing
in
a
higher
reading
and
indicating
a
higher
state
of
charge)
.
NOTE-
Electrolyte
temperature
affects
hydrometer
reading
.
Check
the
electrolyte
temperaturewith
a
thermometer
.
Add
0
.004
to
the
hydrometer
reading
for
every
10°F
(6°C)
that
the
electrolyte
is
above
80°F
(27°C)
.
Sub-
tract
0
.004
from
the
reading
for
every
10°F
(6°C)
that
the
electrolyte
is
below
80°F
(27°C)
.
Before
checking
the
specificgravity
of
a
battery,
load
the
battery
with
15
amperes
for
one
minute
.
lf
the
battery
is
in-
stalled
in
the
vehicle,
this
can
be
done
by
turning
on
the
head-
lights
without
the
engine
running
.
Table
b
lists
the
percentage
of
charge
based
on
specific
gravity
values
.
Table
b
.
Specific
Gravity
of
Battery
Electrolyteat
80
°
F
(27°C)
Specific
gravity
1
Stateof
charge
1
.265
Fully
charged
1
.225
75%
charged
1
.190
50%
charged
1
.155
25%
charged
1
.120
Fully
discharged
The
battery
isin
satisfactory
condition
if
theaverage
specif-
ic
gravity
of
the
six
cells
is
at
least
1
.225
.
If
the
specific
gravity
is
above
this
leve¡,
butthe
battery
lacks
power
for
starting,
de-
termine
the
battery's
senrice
condition
with
a
load
voltage
test,
as
described
below
.
If
the
average
specific
gravity
of
the
six
cells
is
below
1
.225,
remove
the
battery
from
the
luggage
compartment
and
recharge
.
If,
after
recharging,
the
specific
gravity
varies
by
more
than
0
.005
between
any
two
celis,
re-
place
the
battery
.
CHARGING
SYSTEM
TROUBLESHOOTING
