Yamaha MT-03 Service Manual page 377

3. Remove:
• Battery band
• Battery
4. Check:
• Battery charge
a. Connect a pocket tester to the battery termi-
nals.
• Positive tester probe
positive battery terminal
• Negative tester probe
negative battery terminal
NOTE:
• The charge state of an MF battery can be
checked by measuring its open-circuit voltage
(i.e., the voltage when the positive battery ter-
minal is disconnected).
• No charging is necessary when the open-cir-
cuit voltage equals or exceeds 12.8 V.
b. Check the charge of the battery, as shown in
the charts and the following example.
Example
Open-circuit voltage = 12.0 V
Charging time = 6.5 hours
Charge of the battery = 20–30%
5. Charge:
• Battery
(refer to the appropriate charging method)
EWA13300
WARNING
Do not quick charge a battery.
EWA13300
CAUTION:
• Never remove the MF battery sealing caps.
• Do not use a high-rate battery charger since
it forces a high-amperage current into the
battery quickly and can cause bat-tery over-
heating and battery plate damage.
• If it is impossible to regulate the charging
current on the battery charger, be careful
not to overcharge the battery.
• When charging a battery, be sure to re-
move it from the vehicle. (If charging has
to be done with the battery mounted on
the vehicle, disconnect the negative bat-
tery lead from the battery terminal.)
ELECTRICAL COMPONENTS
• To reduce the chance of sparks, do not
plug in the battery charger until the battery
charger leads are connected to the bat-
tery.
• Before removing the battery charger lead
clips from the battery terminals, be sure to
turn off the battery charger.
• Make sure the battery charger lead clips
are in full contact with the battery terminal
and that they are not shorted. A corroded
battery charger lead clip may generate
heat in the contact area and a weak clip
spring may cause sparks.
• If the battery becomes hot to the touch at
any time during the charging process, dis-
connect the battery charger and let the bat
tery cool before reconnecting it. Hot bat-
teries can explode!
• As shown in the following illustration, the
open-circuit voltage of an MF battery sta-
bilizes about 30 minutes after charging
has been completed. Therefore, wait 30
minutes after charging is completed be-
fore measuring the open-circuit voltage.
Charging method using a variable-current
(voltage) charger
a. Measure the open-circuit voltage prior to
charging.
NOTE:
Voltage should be measured 30 minutes after
the engine is stopped.
b. Connect a charger and ammeter to the bat-
tery and start charging.
NOTE:
Set the charging voltage at 16–17 V.If the set-
ting is lower, charging will be insufficient. If too
high, the battery will be over-charged.
c. Make sure that the current is higher than the
standard charging current written on the bat-
tery.
NOTE:
If the current is lower than the standard charg-
ing current written on the battery, set the charg-
ing voltage adjust dial at 20–24 V and monitor
the amperage for 3–5 minutes to check the bat-
tery.
8-50