Edan M3 Vital Signs Monitor Replacement Battery 14.8V 3400mAh

Edan M3 / SE-1 Vital Signs Monitor — 14.8V Li-ion Replacement Battery (21.21.064149)

This 14.8V 3400mAh (50.32Wh) lithium-ion battery replaces the original pack in the Edan M3, M3A Vital Signs Monitor, SE-1, and SE-1 ECG, along with 19 additional compatible models. It restores battery-backed operation for portable patient monitoring — ECG, SpO2, NIBP, and heart rate — when mains power is unavailable or during patient transport. OEM part numbers covered: 21.21.064149, HYLB-102, and TWSLB-005.

• M3 and SE-1 platform compatibility: The M3 and SE-1 series share the same 14.8V four-cell Li-ion architecture, battery bay dimensions, and BMS communication protocol. One pack covers both monitor lines because the charge IC and connector pinout are identical across this platform.
• Bench tested on actual hardware: We cycled this pack on the M3 monitor and confirmed the BMS handshake completes correctly at startup. The charge IC accepted the cell chemistry without flagging a fault, and the battery status indicator advanced normally through all charge states.
• Post-swap power-on self-test: After fitting this battery, allow the M3 to complete its full power-on self-test without interruption. The monitor runs a BMS verification sequence at boot — cutting power during this window causes a false battery fault that persists until the next clean reboot.

Why the M3 alarms low battery immediately after a confirmed full charge

The M3's BMS stores a learned capacity profile from the previous cell. When a new pack is installed, the monitor compares the new cell's first charge cycle against that stored profile and often flags a mismatch as a low-battery condition. This is a BMS learn-cycle issue, not a cell fault. Run one complete charge-discharge cycle on the monitor before clinical deployment. After that cycle, the BMS recalibrates its threshold to the new cell and the alarm clears.

Monitor will not power on after the replacement battery sat in storage

Li-ion cells self-discharge during storage, and the M3's BMS enforces a minimum recovery voltage before it will pass power to the monitor's boot sequence. If the cell drops below approximately 12.0V in storage, the BMS enters deep-discharge protection and the monitor appears completely dead. Place the battery on charge for a minimum of 30 minutes before attempting to power on the device — this allows the charge IC to trickle-charge the pack back above the BMS recovery threshold. Once the pack reads at least 13.5V, a normal boot will proceed.