Saracom EB-10 EPIRB Compatible Battery 14.4V 14000mAh

Saracom EB-10 / SEP-406 / SEP-500 / VEP8 — 14.4V Li-SOCl2 Replacement Battery (4ER34615M)

This is the 4ER34615M lithium-thionyl chloride battery for Saracom EPIRB units — the EB-10, SEP-406, SEP-500, and VEP8. It runs at 14.4V with a 14000mAh (201.6Wh) capacity. These are marine distress beacons; the battery must meet strict output thresholds to pass self-test and transmit a 406 MHz distress signal if the unit activates at sea.

• EB-10, SEP-406, SEP-500, VEP8 fit group: These four Saracom beacon models share the same battery housing dimensions, connector, and 14.4V supply requirement. The BMS in each unit reads voltage at self-test; all four reject cells that fall below the activation threshold, which is why only the correct rated cell passes inspection.
• Bench tested on actual hardware: We tested the 4ER34615M against the beacon's self-test cycle. The cell held voltage through the full test sequence and the BMS confirmed a pass state. No voltage sag was recorded during the simulated activation load pulse.
• Post-replacement registration check: After swapping the battery, verify your beacon's registration with your national maritime authority — COSPAS-SARSAT records tied to your 15-digit hex ID do not update automatically after maintenance. An unregistered or lapsed beacon triggers a false-alarm flag if activated.

Why the Saracom EB-10 fails its self-test after the battery expiry date passes

Li-SOCl2 cells lose capacity through internal self-discharge even when the beacon is never activated. The EB-10's self-test measures open-circuit voltage against a minimum threshold — typically above 13.5V under simulated load. A cell that has sat past its expiry date often reads within normal range at rest but sags below the cutoff the moment the beacon applies a test load. The EPIRB firmware reads that sag as a battery fault and flags the test as failed. Replacing the cell before the stamped expiry date — not after a failed test — keeps the beacon compliant.

Water ingress fault after battery compartment access

The most common error after a battery swap is a failed waterproof seal. The EB-10 and SEP-406 housings use a compression gasket around the battery compartment lid; if the gasket is pinched, seated unevenly, or dried out, the unit will pass a bench self-test but fail on submersion. Inspect the gasket for flat spots or cracking before reassembly. Torque the lid fasteners in a cross pattern rather than one side at a time to keep compression even. If the gasket shows any deformation, replace it before returning the beacon to service.