Battery Charging

73 Digital Multimeter:

SPECIAL TOOLS REQUIRED


WARNING: WEAR SAFETY GLASSES. BATTERY CHARGING CAN BE DANGEROUS. WHILE BEING CHARGED, THE BATTERY PRODUCES A POTENTIALLY EXPLOSIVE MIXTURE OF HYDROGEN AND OXYGEN GASES. KEEP SPARKS, FLAMES AND LIGHTED CIGARETTES AWAY FROM BATTERIES. IN CASE OF ACID CONTACT WITH SKIN, EYES OR CLOTHING, FLUSH IMMEDIATELY WITH LARGE AMOUNTS OF WATER. GET MEDICAL ATTENTION.

NOTE: If excessive gassing or electrolyte spewing occurs during the charge, discontinue charging. The battery has reached serviceable charge. If the battery will not accept at least 5A after 20 minutes of charging, replace the battery

1. Before recharging a discharged battery, inspect and repair the following conditions, if they exist: loose drive belt, pinched or grounded generator voltage regulator wiring, loose connections of the generator voltage regulator wiring at the Generator (GEN) or Voltage Regulator (VR), loose or corroded connections at the battery, starter motor relay or engine, and excessive battery drain due to key off loads.
2. Cold batteries will not readily accept a charge. Therefore, allow the battery to warm up to approximately 5°C (41°F) before charging. This can require 4 to 8 hours at room temperature, depending on the initial temperature and battery size.
3. A battery which has been completely discharged can be slow to accept a charge initially, and in some cases will not accept a charge at the normal charger setting. When a battery is in this condition, charging can be started by the use of the dead battery switch on chargers so equipped.
4. To determine whether a battery is accepting a charge, follow the charger manufacturer's instructions for use of the dead battery switch. if the switch is the spring-loaded type, it must be held in the ON position for up to 3 minutes.
5. After releasing the switch and with the charger still on, measure the battery voltage using Rotunda 73 Digital Multimeter. If it shows 12 volts or higher, the battery is accepting a charge and is capable of being recharged. However. it can require up to 2 hours of charging with batteries colder than 5°C (41°F) before the charge rate is high enough to show on the charger ammeter. It has been found that all non-damaged batteries can be charged by this procedure. If a battery cannot be charged by this procedure, replace it.
6. A rapid recharge procedure has been developed for recharging batteries that have passed the load test and only need a recharge. This can be due to: in-service no-start battery failures (vehicle will not crank due to low battery state of charge) or battery discharged in vehicle due to key off loads.
7. The battery can be rapidly recharged using either of the following methods: perform a 2-hour charge using 20A constant current (manual setting on charger) or perform a 2-hour charge using a constant potential (automatic setting on charger).