The following procedure should be used to recharge a very low or completely discharged battery. Unless this procedure is properly followed, a perfectly good battery may be needlessly replaced.

Tools Required

J 39200 Digital Multimeter

1. Measure the voltage at the battery terminal with a J 39200 . If the battery voltage is below 11 VDC, the charge current will be very low and it could take some time before the battery accepts a current in excess of a few milliamperes. Such low current may not be detectable on some ammeters.
2. Set the battery charger on a high setting.
3. Some chargers feature polarity protection circuitry which prevents charging unless the charger leads are connected to the battery terminals correctly. A completely discharged battery may not have enough voltage to activate this circuitry, even though the leads are connected properly, making it appear that the battery will not accept charging current. Therefore, follow the specific charger manufacturer's instructions explaining how to bypass the polarity protection circuitry, allowing the charger to charge a low-voltage battery.
4. Battery chargers vary in the amount of voltage and current they provide. The time required for a battery to accept measurable charger current at various voltages are as follows:

•	16.0 VDC or more -- up to 4 hours

•	14.0 to 15.9 VDC -- up to 8 hours

•	13.9 VDC or less -- up to 16 hours

5. If the charge current is still not measurable at the end of the above charging times, the battery should be replaced.
6. If the charge current is measurable during the charging time, the battery is considered to be good and charging should be completed in the normal manner. Refer to Battery Charging .
7. It is important to remember that a completely discharged battery must be recharged for a sufficient number of ampere hours (AH) to restore it to a usable state. As a general rule, using the reserve capacity (RC) rating of the battery as the number of ampere hours of charge will usually bring the desired hydrometer indication (green dot) into view. The battery used in this vehicle is rated at 71 RC minutes, therefore, it would be completely recharged as follows:

•	10 ampere charge for 7.1 hours (10 x 7.1) = 71 AH

•	25 ampere charge for 2.84 hours (25 x 2.84) = 71 AH

8. Any battery recharged by this procedure should be load tested to establish serviceability. Refer to Battery Load Test .