Yamaha MM700A Manual page 153

ELECTRICAL SYSTEM
TIME
2 4 6
Charging time (hours)
Specific gravity
I
8 16
10 12 14
Charging
Maintain a good state of charge in batteries used for
starting. When charging the battery, the cells will show
signs of gas bubbling. If one cell has no gas bubbles or if
its specific gravity is low, the cell is probably shorted.
ter charging or if the specific gravity drops quickly, the
battery is defective. A good battery should only self-dis-
charge approximately 1 % each day.
CAUTION
Always remove the battery from the frame
before connecting charging equipment.
WARNING
During charging, highly explosive hydrogen
gas is released from the battery. Charge the
battery only in a well-ventilated area, and
keep open flames and cigarettes away.
Never check the charge of the battery
arcing across the terminais; the resulting
spark can ignite the hydrogen gas.
1. Remove the battery from the frame as described in this
chapter.
2. Connect the positive (+) charger lead to the positive
battery terminal and the negative
negative battery terminal. See Figure 4.
3. Remove all vent caps from the battery, set the charger
at 12 volts, and switch it on. Normally, a battery should be
charged at a slow charge rate of 1/10 its given capacity.
See Table 1 for battery model.
CA UPON
The electrolyte level must be maintained at
the upper level during the charging cycle;
check and refill with distilled water as nec-
essary.
The charging time depends on the discharged condi-
tion of the battery. The chart in Figure 5 can be used to de-
termine approximate charging times at different specific
gravity readings. For example, if the specific gravity of a
battery is 1.180, the approximate charging time would be
6 hours.
5. After the battery has been charged for about 6-8 hours,
turn the charger off, disconnect the leads and check the
specific gravity. It should be within the limits specified in
Table 2. If it is, and remains stable for one hour, the bat-
tery is charged.
147
charger lead to the