RescueME MOB1 Marine Beacon Compatible Battery 6V 1600mAh

RescueME MOB1 — 6V Li-MnO2 Replacement Battery (901S-01509)

This is a 6V, 1600mAh lithium manganese dioxide battery for the RescueME MOB1 man-overboard personal locator beacon. It replaces OEM part 901S-01509 and BBR-901S-01509. The MOB1 is a marine safety device — keeping it powered to spec is a legal and operational requirement, not optional maintenance.

• MOB1 platform fit: The MOB1 uses a dedicated Li-MnO2 cell format — 69 x 18 x 17mm — with a fixed voltage rail and internal BMS logic that validates cell chemistry on power-up. Swapping to the wrong chemistry will cause the self-test to flag a fault, even if the device appears to power on.
• Bench tested on actual hardware: We ran this cell against the MOB1's activation circuit and self-test sequence. The BMS accepted the cell without a fault flag, and the activation threshold was met within spec. No error codes were thrown during the full test cycle.
• Post-replacement seal check: The MOB1 must maintain its waterproof rating after every battery access. Once the battery is seated, press the housing closed and confirm the gasket is fully compressed with no gap around the seam — any lift means water ingress is possible, and the device will not survive immersion.

MOB1 self-test failure after battery replacement

The MOB1 runs a built-in self-test that checks battery voltage, GPS lock, and circuit continuity. If the replacement cell voltage is below the device's activation threshold — even slightly — the self-test will return a fault rather than a pass. Li-MnO2 cells ship at a stable open-circuit voltage, but a cell that has sat in a warehouse past its rated shelf life may read low on first contact. If the self-test fails immediately after fitting this battery, measure the cell voltage directly — it should sit at or above 6V unloaded. A reading below 5.8V means the cell needs replacement before the device can be returned to service.

MOB1 not registering a valid activation after battery swap

After any battery replacement, the MOB1 should be re-tested for activation response and — depending on your jurisdiction — re-registered with the relevant maritime authority. Some national beacon registries tie the device record to a maintenance log, and an updated service date may be required to keep the registration current. In Australia, the AMSA registry and equivalent bodies in the UK and EU recommend notifying the authority after any internal maintenance. Check your beacon's registration record immediately after fitting a new battery, and update the service date to reflect the replacement.