TOHATSU 40 Service Manual page 199

SECTION 7
2. Test the specific gravity of the battery. See the Specific
6
Gravity Test previously discussed in this section.
3. Find the Battery Charge Percent using the Specific
7
Gravity/ Battery Charge Relationship Chart.
4. Calculate the amount of discharge in ampere hours using this
formula:
Amount of Discharge (AH) = Rated Ampere Hours x
Battery Charge Percent x 0.01
Where: RatedAmpere Hours = Manufacturer's rating for
battery being tested.
Battery Charge Percent = Equals value obtained
from chart.
5. Calculate the charging current using this formula:
Charging Current (A) = 0.3 x Rated Ampere Hours
Where: Rated Ampere Hours = Manufacturer's rating for
battery being tested.
6. Calculate the number of hours to charge the battery using this
formula:
Charging (hours) = Amount of Discharge (AH) x 1.5
7. Remove the caps from each cell and begin charging at the
charging current previously determined.
Reduce charging current, and lengthen the
charging time proportionately, if the temperature
of the electrolyte rises above 115˚F [45˚C] or
gassing becomes excessive. Heat will shorten
the life of the battery.
Set the battery charger to the charging current value
previously determined or the nearest lower charging
current value.
8. Monitor the battery voltage while it is charging. If the voltage
suddenly jumps to over 13 volts just after the start of charging, the
plates are probably sulfated and the battery should be replaced.
A good battery will rise to 12 volts immediately and then gradually
go up to 12.5 to 13 volts in about 30 to 60 minutes after charging is
started.
9. If one cell produces little or no gas bubbles during charging, it is
probably shorted and the battery should be replaced.
7-20
Charging Current (A)
CAUTION
NOTE
T1472
T1473
3-/ 4-Cylinder