Battery Service - Operation Of Battery Eye - Charging Service Tips (07-5-8)

BATTERY EYE OPERATION / FUNCTION

The purpose of the battery eye is to indicate the state of charge of the battery in the assembly plant and while on the dealership lot. The battery eye can also indicate the state-of-charge when the vehicle is delivered to the dealership and during the pre-delivery inspection process. The battery eye is made up of a viewing plate, two balls and a small passage. The balls indicate the specific gravity of the electrolyte by floating higher or lower in the passageway. It is important to note that the battery eye checks the specific gravity on only one battery cell.

• RED usually indicates that the battery state-of-charge is at 40 percent or less
• YELLOW indicates that the battery state-of-charge is between 40 and 57 percent
• GREEN indicates that the battery state-of-charge is above 57 percent
• NO COLOR/BLACK sometimes no color can be seen at all and the eye appears black. This could happen after the battery has been in service for several years and some of the plate material has coated the balls
• CLEAR could happen if the battery case becomes damaged and the electrolyte has fallen below the plates

The battery eye is a state-of-charge indicator, but should not be used to condemn a battery after the vehicle has been placed in service. After delivery, many things could happen to cause the battery eye to lead to misdiagnosis of the battery's actual state-of-charge. After the vehicle has been in service, the battery eye does not always accurately reflect the battery state-of-charge. The GR-1 190 Battery Tester/Charge or Micro 490 Digital Battery Analyzer should be used to determine battery condition.

Do not replace a battery based solely on the indication given by the battery eye. The battery eye color simply indicates the battery state-of-charge, not its condition. If the eye indicates the battery may be discharged, Use GR-1 190 Battery Tester/Charger to determine the battery condition or recharge the battery before testing using the Micro 490.

A red or yellow indicator usually means that the battery is discharged, not defective. Therefore, a battery with a red or yellow eye should not automatically be replaced. The indicator could remain red after recharge because the balls are stuck in the passageway.

When new vehicles are delivered to the dealership, be sure to check the state-of-charge indicator within 72 hours. If the battery eye is red, charge the battery until it is fully charged. Refer to the following Battery Charging Procedure.

Batteries discharge while the vehicle is on the lot due to normal parasitic key-off loads. Also, vehicles in inventory are generally driven short distances with heavy electrical loads. Over a period of time (30 days or more), vehicles still in inventory will have shallow to deeply discharged batteries. The vehicle's charging system is designed to supply the vehicle's electrical power needs and maintain the battery near full charge during normal vehicle use. The charging system is not capable of bringing a deeply discharged battery back near full charge in a short amount of time such as allowing the vehicle to idle for 15 minutes to "recharge the battery". Discharged batteries should be charged using an external charger. Refer to the following Battery Charging Procedure.

BATTERY CHARGING PROCEDURE

Dealers with GR-1 190, use the Diagnostic Fast Charge Mode on GR-1 190 for this procedure and for dealers without a GR-1 190 the following procedure applies:

The Micro 490 Digital Battery Analyzer (Rotunda Part Number 162-00004) is extremely accurate if used properly and can distinguish the difference between good, defective, worn out, or discharged-only batteries. This TSB provides proper battery charging procedures for batteries that are identified as "discharged-only". Discharged-only batteries can be recharged using the procedures in this TSB without reducing battery life or charge capacity.

• DEEPLY DISCHARGED - A battery that is drained over a prolonged period of time such as an unsold vehicle, to the point it is dead
• SHALLOW DISCHARGE - A battery that is drained by leaving an accessory on for several hours or a few days, and has a very low charge

The following chart information summarizes two (2) recommended methods of charging.

A battery which has been completely discharged and left in that condition for a prolonged time (such as an unsold vehicle) may be slow to accept a charge initially, and in some cases may not accept a charge at the normal charger setting. When batteries are in this condition, charging can be started by use of the "dead battery" feature on chargers so equipped. Follow charger manufacturer's instructions for use of dead battery switch. If switch is the spring-loaded type, it may need to be held in the ON position for up to 3 minutes.

For additional information, refer to the PTS Website, web based Technician training "Fix It Right The First Time" course "Battery Testing and Charging 34G02W0" (FCS-14246-WEB on www.motorcraft.com).