Battery - Yanmar 4JH2E Service Manual

Chapter 9 Electrical System
1. Battery
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-4JH
Series
2. Battery
2· 1 Construction
Terminal
/Filler cap
~-
Cover
Negative plate
Separate plate
Glass mat
~Positive
plate
The battery utilizes chemical action to convert chemical
energy to electrical energy. This engine uses a Tead acid
battery which stores a fixed amount of power that can be
used when required. After use, the battery can be
recharged and used again.
As shown in the figure, a nonconductive container is filled
with dilute sulfuric acid electrolyte. Lead dioxide positive
plates and lead dioxide negative plates separated by glass
mats are stacked alternately in the electrolyte. The positive
and negative plates are connected to their respective
terminals.
Power is removed from the battery by connecting the load
across these two terminals.
When the battery is discharging, an electric current flows
from the positive plates to the negative plates. When the
battery is being charged, electric current is passed through
the battery in the opposite direction by an external power
source.
2-2 Battery capacity and battery cables
2·2.1 Battery capacity
Since the battery has a minimum capacity of 12V, ?OAH, it
can be used for 100,., 150AH.
minimum
12V - 100AH
Battery capacity
standard
12V - 120AH
cold weather
12V - 150AH
Full charged specific gravity
1.26
2·2.2 Battery cable
Wiring must be performed with the specified electric wire.
Thick, short wiring should be used to connect the battery
to the starter, (soft automotive low-voltage wire [AV wire]).
Using wire other than that specified may cause the fol·
lowing troubles:
Printed in Japan
AOA/029-9002
I
Wire thinner than specified
I
Wire longer than specified
High wiring resistance
Low current
Faulty starting
Battery switch
Single conductor wire
Open circuit caused
by vibrations
Faulty charging
1------;
Key switch
b
The overall lengths of the wire between the battery (+)
terminal and the starter (B) terminal, and between the bat-
tery (-) terminal and the starter (E) terminal, should be
determined according to the following table.
Allowable
Conductor
a+b+c
Voltage wiring cross-
allowable
system voltage section
length
drop area
20mml
Upto2.5m
12V
0.2V or less/100A
(0.0311 in. 'I (98.43 in.)
40mm 1
Up to Sm
(0.062 in. 'I
(196.87 in.)
Note: Excessive resistance in the key switch circuit
(between the battery and start [SJ terminals) can
cause improper pinion engagement. To prevent this,
follow the wiring diagram carefully.
2·3 Inspection
The quality of the battery governs the starting performance
of the engine. Therefore the battery must be routinely in-
spected to ensure that it functions perfectly at all times.
2·3.1 Visual inspection
(1) Inspect the case for cracks, damage and electrolyte
leakage.
(2) Inspect the battery holder for tightness, corrosion, and
damage.
(3) Inspect the terminals for rusting and corrosion, and
check the cables for damage.
(4) Inspect the caps for cracking, electrolyte leakage and
clogged vent holes.
Correct any abnormal conditions found. Clean off rusted
terminals with a wire brush before reconnecting the bat-
9.7
tery cable.