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TSB 06-4-2	BATTERY SERVICE - OPERATION OF BATTERY EYE - CHARGING SERVICE TIPS
Publication Date: February 10, 2006

FORD:	1998-2000 Contour 1998-2003 Escort 1998-2006 Crown Victoria, Mustang, Taurus 2000-2006 Focus 2004-2005 Thunderbird 2005-2006 Five Hundred, Freestyle 2006 Fusion 1998-2003 Windstar 1998-2006 E-Series, Expedition, Explorer, F-150, Ranger 1999-2006 F-53, F-Super Duty 2000-2005 Excursion 2001-2005 Explorer Sport Trac 2001-2006 Escape 2004-2006 Freestar 2005-2006 Escape Hybrid 2000-2006 F-650, F-750 2006 Low Cab Forward
LINCOLN:	1998-2002 Continental 1998-2006 Town Car 2000-2006 LS 2006 Zephyr 1998-2006 Navigator 2002 Blackwood 2003-2005 Aviator 2006 Mark LT
MERCURY:	1998-2005 Sable 1998-2006 Grand Marquis 1999-2002 Cougar 2005-2006 Montego 2006 Milan 1998-2006 Mountaineer 2000-2002 Villager 2004-2006 Monterey 2005-2006 Mariner 2006 Mariner Hybrid

This article supersedes TSB 05-09-18 to update the Service Procedure.

ISSUE:

This TSB describes the operation and function of the Battery Eye and correct Battery Recharging procedures.

ACTION:

Refer to the following Service Tips to avoid misdiagnosis of a battery using the Battery Eye, and to determine the best way to charge a battery that may be discharged.

SERVICE TIPS

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.