Radio Beacon SAR-9 Replacement Battery 7.2V 14000mAh 2ER34615M

Radio Beacon SAR-9 / NBB-441 — 7.2V Li-SOCl2 Replacement Battery (2ER34615M)

This is a 7.2V, 14000mAh Li-SOCl2 replacement battery for the Radio Beacon SAR-9 EPIRB and compatible marine distress beacons including the NBB-441, JQX-30A, and FT501. It matches OEM part numbers 2ER34615M and A3-06-2613. Li-SOCl2 chemistry is mandatory for EPIRBs — it maintains voltage stability across a wide temperature range and holds charge through years of standby without significant self-discharge.

• SAR-9, NBB-441, JQX-30A, FT501 compatibility: These models share the same battery form factor, terminal configuration, and 7.2V voltage requirement. The SAR-9 and its related units accept the 2ER34615M cell because it fits the physical housing and meets the activation current draw the transmitter circuit requires during a 406 MHz distress burst.
• Bench tested on actual hardware: We confirmed terminal polarity, physical fit, and open-circuit voltage against the 2ER34615M specification. Li-SOCl2 cells at rest read slightly above nominal — a reading at or below 6.8V indicates a depleted cell and the unit will likely fail self-test.
• Re-registration after battery replacement: After fitting a new battery, re-register your beacon with your national maritime authority. Many EPIRB registrations are tied to a service record and some jurisdictions require renewed registration following any maintenance. Check your vessel's EPIRB logbook for the next required inspection date.

Why the SAR-9 fails self-test even with a recently replaced battery

The SAR-9's internal self-test draws a short high-current pulse to simulate transmitter activation. Li-SOCl2 cells that have been stored incorrectly — particularly above 30°C for extended periods — can develop elevated internal resistance without showing obvious voltage drop at rest. The cell reads 7.2V open-circuit but collapses under load during the test pulse. If the unit fails self-test immediately after battery installation, check the storage history of the replacement cell and verify the open-circuit voltage is above 7.0V before fitting.

SAR-9 self-test LED showing fault code after battery swap

A fault LED pattern after a battery swap usually means one of three things: the battery contacts are not fully seated, the waterproof gasket shifted during reassembly and triggered a housing integrity fault, or the cell voltage is below the activation threshold. Remove the battery, clean the contact pins with a dry cloth, reseat the cell firmly, and recheck the gasket alignment before closing the housing. If the fault code persists with a confirmed good cell, consult the SAR-9 manual's LED diagnostic table — each flash pattern maps to a specific fault, not a general failure.