1998 BMW 740I battery

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RepairsIndexOverview Controls Car care Technology Data
BatteryInstallation location, BMW 740i/LThe battery is located behind the right-
side trim panel in the luggage compart-
ment.
Grasp the handle in the upper panel
and fold it down.380de671
Installation location, BMW 750iLTwo batteries are installed in the BMW
750iL. They are located in the luggage
compartment behind the right side trim
panel.
To check the charge condition or
for removal or installation, please
consult your BMW center.< 380de654
SymbolsYou will find the following symbols on
your car battery. To avoid injury, please
observe the corresponding precautions
whenever you work with or near the
battery.
Please read the following infor-
mation before working with the
battery.
Wear eye protection. Do not al-
low particles containing battery
acid or lead to come into con-
tact with your eyes, your skin, or your
clothing.
Battery acid is extremely corro-
sive. Wear eye protection and
protective gloves. Do not tip the
battery. Battery acid can leak from the
ventilation openings.
Be sure that children keep well
away from batteries and battery
acid.
Never allow sparks or open
flame, and do not smoke in the
vicinity of the battery.
Avoid sparks from electrical cables or
electrical equipment. Turn the key to po-
sition 0 in the steering lock when the
battery is disconnected or connected.

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BatteryDo not short circuit the battery termi-
nals. This creates a risk of personal in-
jury from high-voltage sparks.
A highly-explosive gas is
generated when the battery is
charged.
If you happen to get acid in
your eyes, rinse thoroughly for
15 minutes with clear water.
Consult a physician immediately. If you
get acid spray on your skin or clothing,
rinse with plenty of water. If electrolyte
is accidentally ingested, consult a phy-
sician immediately.
In order to protect the battery
case from ultraviolet radiation,
do not place it in direct sunlight.
A discharged battery can freeze. Store
the battery in areas where temperature
remains above freezing.Car careThe battery is completely maintenance-
free, that is, the original electrolyte will
normally last for the service life of the
battery.
Charge condition – BMW 740i/LYou can read the charge condition of
the battery with the "Magic Eye" (a hy-
drometer) (not released at this time):
>Green: Adequate charge
>Black: Not charged adequately. The
battery must be recharged. Please
contact your BMW center
>Yellow: Replace the battery.380de655
Charging the batteryCharge the battery in the vehicle only
when the engine is off. Charge the bat-
tery using the supplementary positive
terminal and ground (terminal) in the en-
gine compartment (refer to "Jump-start-
ing" on page 179).
On the BMW 750iL, there is an auto-
matic switch between the two batteries
during charging.
Before performing any work on
the electrical system, disconnect
the cable from the negative terminal. If
you do not, short circuits can create the
risk of fire or personal injury.
If a jump start is necessary, connect the
cables only to the auxiliary terminal for
jump starting and a ground in the en-
gine compartment in order to avoid
damage to the batteries (refer to
"Jump-starting" on page 179).<

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RepairsIndexOverview Controls Car care Technology Data
BatteryIf you plan to store the vehicle for
longer than 4 weeks, disconnect the
battery from the vehicle electrical sys-
tem by disconnecting the cable at the
negative terminal.
If you intend to store your car for longer
than six weeks: Remove the battery,
charge it and store it in a cool (but frost-
free) room. After a period not exceeding
6 months and before reinstalling the
battery, have it recharged. If it is not re-
charged, it will not be serviceable. Ev-
ery time the battery is discharged, es-
pecially over extended periods, its
service life is reduced.
Avoid environmental pollution
when disposing of old batteries.<
Return used batteries to a recy-
cling point or to your authorized
BMW center. Maintain the battery in an
upright position for transport and stor-
age. Secure the battery against tilting in
transit.<
Removal and installation
Do not disconnect the battery
when the engine is running. Dis-
connecting the battery cable when the
engine is running will cause a voltage
surge that will damage the vehicle's on-
board electronics.
Do not make any modifications in the
wires to the positive terminal. If you do
so, the protective function of the safety
battery terminal is no longer ensured.
Repairs and disposal may only be per-
formed by specially-trained personnel.<
BMW 750iL: Please contact your autho-
rized BMW center for additional infor-
mation.
BMW 740i/L: When removing the bat-
tery, disconnect the negative terminal
first, then the positive terminal.
Unscrew the battery retaining clamp
(arrow).
When installing the battery, connect the
positive terminal first, then connect the
negative terminal.
When installing a battery, be sure
that it is mounted properly. If the
battery is not mounted properly, it will
not be adequately secured in case of an
accident.< 380de653

176n
FusesIf an electrical accessory should fail,
switch it off and check the fuse.In the engine compartment1 Open the hood. Press the cover fas-
teners (arrows) forward and open the
cover
2 Use the plastic tweezers (located on
the inside of the cover) to remove the
fuse for the accessory or equipment
that has stopped working from its
socket
3 If the fuse is burned through (the
metal strip is melted and separated),
replace it with a new fuse of the same
ampere rating (color code).380de085
A list of the fuses, their respective am-
pere ratings and the equipment in their
circuits is provided next to the fuse box.
When you close the fuse box, be sure
that the cover is seated securely.
Additional fuses are provided in the
luggage compartment (refer to next
column).
The fuse for continuous positive current
is located in a separate fuse box above
the battery. If this fuse is defective, refer
the problem to your BMW center for re-
pair.Do not attempt to repair a burned
fuse or replace it with a fuse hav-
ing a different color or amperage rating.
To do this could cause a fire in the vehi-
cle resulting from a circuit overload.<
If the fuse fails repeatedly, refer the
problem to your BMW center for repair.

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RepairsIndexOverview Controls Car care Technology Data
FusesIn the luggage compartment1 Fold down the right-hand trim panel
with the upper handle
2 BMW 750iL: Unscrew the hexagon
nut (arrow), lift the battery support up
slightly and swing it inward together
with the battery380de672
3 Move the sound insulation material
slightly to the side.
A list of the fuses, their respective am-
pere ratings and the equipment in their
circuits is provided on the rear of the
side trim.380de124

178n
Fuel filler door Sliding/Tilt sunroofManual release1 Use the handle to lower the trim
panel on the right side of the luggage
compartment
2 BMW 750iL: Unscrew the hexagon
nut (arrow), lift the battery support up
slightly and swing it inward together
with the battery380de672
3 Pull the knob with the fuel pump
symbol.380de614
Manual operation1 Remove the interior lamp (refer to
page 166). Reach into the opening
and push out the panel
2 Remove the plug (arrow) and use the
Allen wrench from the onboard tool
kit (refer to page 162) to turn the slid-
ing/tilt sunroof in the desired direc-
tion.380de096

179n
RepairsIndexOverview Controls Car care Technology Data
Jump-startingNever use spray starter fluids to start
the engine.
If the battery is discharged, you can use
two jumper cables to start your car with
power from the battery of a second ve-
hicle. Always use jumper cables with
fully insulated handles on the terminal
clamps.
Do not touch high-voltage wiring
and cables on a running engine.
There is a risk of fatal injury if you do
this.<
Carefully comply with the following in-
structions to avoid personal injury and
damage to one or both vehicles:
1 Ensure that the battery on the sup-
port vehicle is also rated at 12 volts,
and that the capacities of the two
batteries (Ah) are roughly comparable
(printed on casing)
2 Leave your battery connected to the
car electrical system
3 Make sure that there is no contact
between the bodywork of the two ve-
hicles – short circuit risk.
4 Start by connecting the jumper cable
from the positive terminal of the sup-
port vehicle to the positive terminal
connector located in your BMW's en-
gine compartment. The cover of the
auxiliary terminal for jump starting is
marked with "Batt. +" (refer to the il-
lustration). Remove by pulling tab.
The illustration shows the auxiliary
terminal for jump starting the BMW
740i/L as an example. For the BMW
750iL: Refer to "Engine compart-
ment" on page 140380de089
5 Then connect the negative terminals.
Attach the cable to either the support
vehicle's negative battery terminal,
or to a suitable ground on its engine
or bodywork. Then connect the other
end of the cable to ground on the ve-
hicle's engine or bodywork which is
to be started. Then connect the other
end of the cable to a ground on your
vehicle's engine or bodywork (for in-
stance, the nuts on the strut dome.
Refer to the arrows in the illustration
above)
Follow the same sequence for
connecting the jumper cables if
you assist in jump-starting another ve-
hicle. If you do not, there is a risk of in-
jury caused by spark generation at the
battery.< 380de117

180n
Jump-starting Towing the vehicle6 If the battery of the support vehicle is
weak, start its engine and let it run
7 Start the engine on the vehicle need-
ing the jump-start, and allow it to run
as usual. If the first start attempt is
not successful, wait a few minutes
before another attempt in order to
allow the discharged battery to re-
charge
8 Before disconnecting the jumper ca-
bles from your BMW, turn on the rear
window defroster and set the blower
to the highest speed; allow the en-
gine to run approx. 10 seconds. This
will prevent a voltage surge from the
voltage regulator to the electrical ac-
cessories
9 Then disconnect the jumper cables in
reverse sequence.
Have the battery recharged if neces-
sary.
Tow fittingThe screw-in tow fitting is stored in the
onboard tool kit; be sure that it remains
in the vehicle at all times. This fitting is
designed for installation in the tow
sockets located at the front and rear of
the vehicle, and is intended for towing
on proper road surfaces only.
It should not be used to pull a vehicle
out of deep snow, mud, sand, etc. Al-
ways observe all applicable towing laws
and regulations.Access to tow socketsFront:
Apply pressure to the arrow symbol on
the cover panel to remove.380de087
Rear:
Apply pressure to the arrow symbol on
the cover panel to remove.
Screw the tow fitting in until it bot-
toms firmly. If this is not done, the
threads could be damaged.
Do not tow the vehicle by any compo-
nents of the running gear, or lash them
down in any way. If you do so, the com-
ponents could be damaged, leading to
possible accidents.<
Use only a nylon towing strap to tow the
vehicle, since the inherent resilience of
this material helps protect both vehicles
from sudden jerking movements.380de088