Yanmar 4JH2E Service Manual page 320

Chapter 9 Electrical System
2. Battery
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4JH
Serks
2·4 Charging
2·4.1 Charging methods
There are two methods of charging a battery: normal and
rapid.
Rapid charging should only be used in emergencies.
• Normal· charging ... Should be conducted at a current of
1110 or less of the indicated battery
capacity (10A or less for a 100AH
battery).
• Rapid charging ... Rapid charging is done over a short
period of time at a current of 1/5
~
112 the indicated battery capacity
(20A
~
SOA for a 100AH battery).
However, since rapid charging
causes the electrolyte temperature
to rise too
high,
special care must
be exercised.
2·4.2 Charging procedure
(1) Check the specific gravity and adjust the electrolyte
level.
(2) Disconnect the battery cables.
(3) Connect the red clip of the charger to the (+) battery
terminal and connect the black clip to the(-) terminal.
(4) Set the current to 1/10 ~ 1/5 of the capacity indicated
on the outside of the battery.
(5) Periodically measure the specific gravity during
charging to make sure that the specific gravity
remains at a high fixed value. Also check whether
gas is being generated.
2·4.3 Charging precautions
(1) Remove the battery caps to vent the gas during
charging.
(2) While charging, ventilate the room and prohibit
smoking, welding, etc.
(3) The electrolyte temperature should not exceed 45°C
during charging.
(4) Since an alternator is used on this engine, when
charging with a charger, always disconnect the battery
(+)cable to prevent destruction of the diodes.
(Before disconnecting the(+) battery cable, disconnect
the(-) battery cable (ground side].)
Printed En Japan
AOAl 029-9002
9-9
1.29
1.28
1.27
Specific
gravity
1.26
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Electrolyte temperature (°C)
Electrolyte temperature and specific gravity
2·5 Battery storage precautions
The life of a battery depends considerably on how it is
handled. Generally speaking, however, after about two
years its performance will deteriorate, starting will become
difficult, and the battery will not fully recover its original
charge even after recharging. Then it must be replaced.
(1) Since the battery will self-discharge about 0.5%/day
even when not in use, it must be charged 1 or 2 times a
month when it is being stored.
6
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Self-discharge/
day(o/o) 3
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Number of days after charging
(2) If charging by the engine alternator is insufficient
because of frequent starts and stops, the battery will
rapidly lose power.
Charge the battery as soon as possible after it is used
under these conditions.
(3) An easy-to-use battery charger that permits home
charging is available from Yan mar. Take proper care of
the battery by using the charger as a set with a
hydrometer.
When the specific gravity has dropped to about 1.16
and the engine will not start, charge the battery up to a
specific gravity of 1.26 (24 hours).
(4) Before putting the battery in storage for long
periods, charge it for about 8 hours to prevent rapid
aging.
Simple charger