5A•2 Starting and charging systems
component concerned. The owner whose
interest extends beyond mere component
renewal should obtain a copy of the
"Automobile Electrical & Electronic Systems
Manual", available from the publishers of this
manual.
It is necessary to take extra care when
working on the electrical system, to avoid
damage to semi-conductor devices (diodes
and transistors), and to avoid the risk of
personal injury. In addition to the precautions
given in "Safety first!" observe the following
when working on the system:
Always remove rings, watches, etc before
working on the electrical system. Even with the
battery disconnected, capacitive discharge
could occur if a component's live terminal is
earthed through a metal object. This could
cause a shock or nasty burn.
Do not reverse the battery connections.
Components such as the alternator, electronic
control units, or any other components having
semi-conductor circuitry, could be irreparably
damaged.
If the engine is being started using jump
leads and a slave battery, connect the
batteries positive-to-positive and negative-to-
negative (see "Booster battery (jump)
starting"). This also applies when connecting a
battery charger.
Never disconnect the battery terminals, the
alternator, any electrical wiring, or any test
instruments, when the engine is running.
Do not allow the engine to turn the alternator
when the alternator is not connected.
Never "test" for alternator output by
"flashing" the output lead to earth.
Never use an ohmmeter of the type
incorporating a hand-cranked generator for
circuit or continuity testing.
Always ensure that the battery negative lead
is disconnected when working on the
electrical system.
Before using electric-arc welding equipment
on the car, disconnect the battery, alternator,
and components such as the fuel
injection/ignition electronic control unit, to
protect them from the risk of damage.
The radio/cassette unit fitted as standard
equipment by Saab from 1994-on has a built-
in security code, to deter thieves. If the power
source to the unit is cut, the anti-theft system
will activate. Even if the power source is
immediately reconnected, the radio/cassette
unit will not function until the correct security
code has been entered. Therefore, if you do
not know the correct security code for the
radio/cassette unit, do not disconnect the
battery negative terminal of the battery, nor
remove the radio/cassette unit from the
vehicle. Refer to "Radio/cassette unit anti-theft
system - precaution" for further information.
Standard and low-maintenance
battery - testing
1 If the vehicle covers a small annual mileage,
it is worthwhile checking the specific gravity of
the electrolyte every three months, to
determine the state of charge of the battery.
Use a hydrometer to make the check, and
compare the results with the following table.
Note that the specific gravity readings assume
an electrolyte temperature of 15°C (60°F); for
every 10°C (18°F) below 15°C (60°F), subtract
0.007. For every 10°C (18°F) above 15°C
(60°F), add 0.007. However, for convenience,
the temperatures quoted in the following table
are ambient (outdoor air) temperatures, above
or below 25°C (77°F):
Above Below
25°C (77°F) 25°C (77°F)
Fully-charged 1.210 to 1.230 1.270 to 1.290
70% charged 1.170to1.190 1.230 to 1.250
Fully-discharged
1.050to1.070 1.110to1.130
2 If the battery condition is suspect, first
check the specific gravity of electrolyte in each
cell. A variation of 0.040 or more between any
cells indicates loss of electrolyte or
deterioration of the internal plates.
3 If the specific gravity variation is 0.040 or
more, the battery should be renewed. If the
cell variation is satisfactory but the battery is
discharged, it should be charged as described
later in this Section.
Maintenance-free battery - testing
4 In cases where a "sealed for life"
maintenance-free battery is fitted, topping-up
and testing of the electrolyte in each cell is not
possible. The condition of the battery can
therefore only be tested using a battery
condition indicator or a voltmeter.
5 A battery with a built-in charge condition
indicator may be fitted. The indicator is
located in the top of the battery casing, and
indicates the condition of the battery from its
colour. If the indicator shows green, then the
battery is in a good state of charge. If the
indicator turns darker, eventually to black,
then the battery requires charging, as
described later in this Section. If the indicator
shows clear/yellow, then the electrolyte level
in the battery is too low to allow further use,
and the battery should be renewed. Do not
attempt to charge, load or jump-start a battery
when the indicator shows clear/yellow.
6 If testing the battery using a voltmeter,
connect the voltmeter across the battery, and
compare the result with those given in the
Specifications under "charge condition". The
test is only accurate if the battery has not been
subjected to any kind of charge for the
previous six hours, including charging by the
alternator. If this is not the case, switch on the
headlights for 30 seconds, then wait four to
five minutes after switching off the headlights
before testing the battery. All other electrical
circuits must be switched off, so check (for
instance) that the doors and tailgate or bootlid
are fully shut when making the test.
7 If the voltage reading is less than 12.2 volts,
then the battery is discharged. A reading of
12.2 to 12.4 volts indicates a partially-
discharged condition.
8 If the battery is to be charged, remove it
from the vehicle (Section 4) and charge it as
described in the following paragraphs.
Standard and low-maintenance
battery - charging
Note: The following is intended as a guide
only. Always refer to the manufacturer's
recommendations (often printed on a label
attached to the battery) before charging a
battery.
9 Charge the battery at a rate of 3.5 to
4 amps, and continue to charge the battery at
this rate until no further rise in specific gravity
is noted over a four-hour period.
10 Alternatively, a trickle charger charging at
the rate of 1.5 amps can safely be used
overnight.
11 Specially rapid "boost" charges which are
claimed to restore the power of the battery in
1 to 2 hours are not recommended, as they
can cause serious damage to the battery
plates through overheating.
12 While charging the battery, note that the
temperature of the electrolyte should never
exceed 37.8°C(100°F).
Maintenance-free battery -
charging
Note: The following is intended as a guide
only. Always refer to the manufacturer's
recommendations (often printed on a label
attached to the battery) before charging a
battery.
13 This battery type requires a longer period
to fully recharge than the standard type, the
time taken being dependent on the extent of
discharge, but it can take anything up to three
days.
14 A constant-voltage type charger is
required, to be set, where possible, to 13.9 to
14.9 volts with a charger current below 25
amps. Using this method, the battery should
be usable within three hours, giving a voltage
reading of 12.5 volts, but this is for a partially-
discharged battery and, as mentioned, full
charging can take considerably longer.
15 Use of a normal trickle charger should not
be detrimental to the battery, provided
excessive gassing is not allowed to occur, and
the battery is not allowed to become hot.
Refer to Chapter 12.