When charging the battery, observe the following conditions:
| • | Use a constant voltage power supply with an end charge voltage
of 16.0 volts-direct current (VDC) and equipped with a voltmeter that is accurate
within 1 percent. |
| • | When charging more than one battery, connect the batteries in
parallel with each other; positive to positive (+ to +) and negative to negative
(- to -). |
| • | Ambient (surrounding) temperature should be 15-38°C
(60-100°F). A battery that is extremely cold may not accept current
for several hours after charging has begun. |
| • | Ventilate the charging area. |
| • | Do not charge the battery if the electrolytes are frozen. |
| • | If the battery feels hotter than 52°C (125°F), or if violent
gassing or spewing of electrolyte through the vent holes occurs, discontinue
charging or reduce the charging rate. |
Charging Procedure
- A battery with a built-in hydrometer showing a green dot does
not require charging unless the battery has just been discharged (by cranking
the engine).
- Connect the battery charger cables to the positive and the negative
battery terminals. Make sure all charger cable-to-battery terminal connections
are clean and tight.
Important: Do not use the charge settings for jump starting the vehicles.
- Charge the battery using the charge setting for 12 VDC batteries that
gives the highest charge rate to the battery. Refer to the battery charger
manufacturer's instructions.
- Charge the battery until the green dot appears in the hydrometer.
Check the battery every half-hour. The battery may need to be tipped or shaken
gently in order for the green dot to appear.
- After charging, test the battery. Refer to
Battery Load Test
.
Charging Time Required
The time required in order to charge a battery will vary depending upon
the following factors:
| • | Size of battery -- A completely discharged, large (heavy
duty) battery requires more than twice the recharging time as a completely
discharged small (passenger car) battery. |
| • | Temperature -- A longer time will be needed to charge any
battery at -18°C (0°F) than at 27°C (80°F). When a fast
charger is connected to a cold battery, the current accepted by the battery
will be very low at first. The battery will accept a higher rate of current
as it warms. |
| • | Charger capacity -- A charger which can supply only 5 amperes
will require a much longer charging period than a charger that can supply
30 amperes or more. |
| • | State-of-charge -- A completely discharged battery requires
more than twice as much charge time as that of a half charged battery. Because
the electrolyte is nearly pure water and a poor conductor in a completely
discharged battery, the current accepted by the battery is very low at
first. Later, as the charging current causes the electrolyte acid content
to increase, the charging current will also increase. |
| | Any battery discharged by parasitic load, and then allowed to stand
in this condition for a period of time, may not readily accept a charge. However,
if recharged long enough, many batteries will return to a good usable condition. |
| | If the battery remains in an extremely discharged condition for a prolonged
period, it can become permanently damaged. This damage can be accelerated
by low temperatures. Batteries which are extremely discharged can freeze
at temperatures as high as -6°C (20°F) and be permanently
damaged. |
| • | In order to prevent battery damage and recharge problems, vehicles
which are not going to be in service within a 20-day period should have the
battery negative (-) cable disconnected in order to remove the constant
drain on the battery. If this is not possible, the battery should be recharged
periodically every 20-45 days until the green dot is visible in the
hydrometer or an open circuit voltage of 12.4 VDC is obtained. |
