Subaru Legacy 2004 Service Manual page 429

D: MEASUREMENT
WARNING:
Do not bring an open flame close to the battery
at this time.
CAUTION:
• Prior to charging, corroded terminals should
be cleaned with a brush and common caustic
soda solution.
• Be careful since battery electrolyte overflows
while charging the battery.
• Observe instructions when handling the bat-
tery charger.
• Before charging the battery on vehicle, dis-
connect the battery ground terminal to prevent
damage of generator diodes or other electrical
modules.
1. JUDGMENT OF BATTERY IN CHARGED
CONDITION
1) Specific gravity of electrolyte should be held
within the specific range from 1.250 to 1.290 for
more than one hour.
2) Voltage per battery cell should be held at a spe-
cific value in a range from 2.5 to 2.8 V for more than
one hour.
2. CHECK HYDROMETER FOR STATE OF
CHARGE
Hydrometer Charge bat-
indicator tery
Green Above 65%
Dark Below 65%
Low electro-
Clear
lyte
* Check electrical system before replacement.
3. NORMAL CHARGING
Charge the battery at current value specified by
manufacturer or at approx. 1/10 of battery's am-
pere-hour rating.
Battery
Corrective action
Load test
Charge battery
Replace battery*
(If cranking is difficult)
SC(H4SO 2.0)-21
STARTING/CHARGING SYSTEMS
4. QUICK CHARGING
Quick charging is a method that the battery is
charged in a short period of time with a relatively
large current by using a quick charger.
Since a large current flow raises electrolyte temper-
ature, the battery is subject to damage if the large
current is used for prolonged time. For this reason,
the quick charging must be carried out within a cur-
rent range that will not increase the electrolyte tem-
perature above 40"C (104"F).
Also the quick charging is a temporary means to
bring battery voltage up to a fair value and, as a
rule, a battery should be charged slowly with a low
current.
CAUTION:
• Observe the items in 3. NORMAL CHARGING.
• Never use more than 10 A when charging the
battery because it will shorten the battery life.