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Aerospace Electronic Systems Grimes Aerospace Company A Subsidiary of Honeywell 550 State Route 55 Urbana, Ohio 43078

937.484.2000 937.484.2101 Fax

28 November 2005

TECHNICAL INFORMATION LETTER NO. 384B TO: All Boeing 737, DC 9, Airbus A 300, and de Havilland DHC-8 Operators SUBJECT: Capacitance Test for the 61-0478-9, 61-0478-11, and 61-3800-1 Battery Assemblies APPLICABILITY: 60-1321 Power Supply, CMM 33-50-42 60-1411 Power Supply, CMM 33-50-29 60-4068 Power Supply, CMM 33-50-52 60-4222 Power Supply, CMM 33-50-61 60-4889 Power Supply, CMM 33-50-59 60-3844 Power Supply, CMM 33-50-67 60-5025 Power Supply, CMM 33-50-72 BACKGROUND It was brought to the attention of the Technical Publications Group that the revisions of the above CMMs were released to the airlines without the Capacitance Test and Deep Cycle Procedure in the Repair section. The following Capacitance Procedure will be added to each manual's Repair Section at the next revision to the manual. WARNING: DO NOT SHORT-CIRCUIT BATTERIES. ALWAYS TAPE WIRE LEADS UNTIL

READY TO CONNECT. The Battery Assembly is to be outside the Power Supply before starting the procedure. Refer to the CMM for instructions on removing the battery assembly. 1. General Repair General repair consists of replacing parts determined to be defective during CHECK,

TESTING, and FAULT ISOLATION.

2. Battery Restoration Procedure

A. Discharge (See Figure 1)

Discharge each cell in the battery pack separately until the voltage across each cell is below 0.2 Vdc. Immediately remove the load.

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B. Charge (See Figure 2)

Charge the battery pack by supplying 250 mA for at least 16 hours. More than one battery pack can be charged by one power supply at the same time by connecting the battery packs in series. Battery packs should not be charged in parallel unless individual charging resistors are provided; e.g., 75 ohms/5 W to charge a battery (six series-connected cells) using a 28-Vdc supply.

BATTERY DISCHARGE SETUP

FIGURE 1.

250 mA

BATTERY PACK CHARGE SETUP FIGURE 2.

Battery Pack

(6 Cells)

Power Supply

A

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C. Capacitance Test (See Figure 3)

CAUTION: DISCHARGE OF THE PACK DURING THIS TEST FOR MORE THAN 20 MINUTES CAN LEAD TO DAMAGE OF ONE OR MORE CELLS DUE TO CELL REVERSAL.

Connect the battery pack to a 2-ohm, 40-watt load through an ammeter. The battery

pack should deliver 3.3 Amps, minimum, for 20 minutes. During discharge, the minimum cell voltage must be 1.1 Vdc. If below 1.1 Vdc, replace the cell.

BATTERY CELL CAPACITANCE TEST SETUP FIGURE 3.

D. Charge Recharge the Battery Pack after the capacitance test.

RECOMMENDED OPERATOR ACTION Should you need additional information, contact a Honeywell / Grimes representative at the following address and phone number:

Grimes Aerospace Company 550 State Route 55 Urbana, Ohio 43078 Phone: (937) 484-2000 Telefax: (937) 484-2101 SITA: DAYFLCR