For 1990-2009 cars

### General Rules

• | Do not charge the battery if the hydrometer is clear or yellow - tap the hydrometer lightly to dislodge any gas bubbles. If the indicator is still clear or yellow, replace the battery.

• | Charger settings from 3 to 80 amps are acceptable as long as electrolyte does not spew out of the vents or the battery does not feel excessively hot (over 52°C [125°F]).

• | The battery is sufficiently charged when the green dot in the hydrometer remains visible.

• | Do not tilt battery at more than a 45° angle.

• | Make sure the battery hold-downs are tight. Loose hold-downs will shake the plate material off the grids and shorten battery life.

• | Repeatedly discharging the battery (deep cycling) will shorten battery life

• | Battery shield must be installed to protect the battery from heat.

### Battery Charging

1. Properly connect battery to charger and connect charger to power source.
2. Set charging rate to high setting and charge battery.

• | Chargers of 75 amperes or more should produce charging times of 1 to 4 hours.

• | Smaller chargers of 10 amperes or less may require charging times of 24 hours or more.

3. Check hydrometer indicator hourly for green dot. Gently tap on hydrometer to eliminate possibility of hydrometer ball sticking. If green dot is not visible, continue charging.
4. Monitor battery for spewing, gassing or case temperature above 52°C (125°F). If this occurs, unplug charger, disconnect charger from battery and load test.
5. When green dot appears and remains, the battery is 65 percent or more charged.
6. Unplug charger, disconnect charger from battery.

### Completely Discharged Battery

When battery voltage is below 11 volts, the weak electrolyte is very resistant to charger current. The battery will draw only a few milliamps of charger current and it may be some time before current flow to the battery is high enough to read on most ammeters.

If the current is measurable after the recommended times (refer to step 4 below), the battery is good and the charging should proceed at the normal rate.

Remember that a completely discharged battery must be charged until the green eye appears.

### Charging a Flat battery

Important: Unless this procedure is followed precisely, a perfectly good battery may be needlessly replaced.

A battery that is below 11 volts will require a battery charger that has the ability to produce 15.5-16 volts on the highest setting.

To test output capability of a battery charger, connect battery charger to battery that reads below 11 volts. Take a voltage reading across positive and negative terminals of battery with charger on highest setting. If reading is not greater than 15.5 volts it will not start the chemical reaction needed to charge battery. A higher output battery charger must be used.

1. Measure voltage across battery terminals with a DVOM. If voltage is below 11 volts, charge current will be low and it could take some time before battery accepts more than a few milliamps.
2. Set charging rate to highest setting (for a 12 volt battery). If battery charger has a timer, set timer to 30 minutes. Check battery for a green eye or excessive temperature 52°C (125°F) every 30 minutes.
3. Some chargers may have polarity protection circuits in them. This prevents charging unless the leads of charger are connected to battery terminals correctly. A completely discharged battery may not have enough voltage to activate this circuit, even though the leads are hooked up correctly. This makes it appear that battery does not want to accept charging current. Therefore, follow manufacturer's operating instructions, telling how to by-pass circuitry so that the charger can be turned on to charge battery.
4. Battery chargers can vary in amount of voltage and current they provide. The time required for a completely discharged battery to accept measurable charger current at various charging voltages may be as follows:

Important: These times are required for a battery to begin to take a charge.

Voltage | Charger Settings | Hours
--- | --- | ---
16.0 or more | High Boost | Up to 4 hours
14.0 to 15.9 | Medium Boost | Up to 8 hours
13.9 or less | Low Boost | Up to 16