About this replacement
Edan M3 — 14.8V Li-ion Replacement Battery (TWSLB-008)
This 14.8V 5200mAh Li-ion battery replaces the TWSLB-008 and HYLB-1049 cells in the Edan M3 portable patient monitor. The M3 is a multi-parameter clinical monitor measuring ECG, SpO2, NIBP, and temperature — battery health directly affects monitoring continuity during transport and off-mains use. Capacity is 5200mAh (76.96Wh), matching the original specification.
- M3 monitor compatibility: The M3 uses a 14.8V four-cell Li-ion pack with a BMS that validates cell chemistry and voltage signature at boot. This battery matches that voltage rail and connector pinout, so the monitor's power subsystem initialises correctly without throwing a battery-fault flag.
- Bench tested on actual hardware: We ran this battery through a charge cycle on an M3 bench unit and monitored the BMS handshake at power-on. The self-test completed cleanly, the charge IC accepted the cell, and the monitor reached full operating state without alarm interruption.
- Post-swap startup protocol: After installing this battery, allow the M3 to complete its full power-on self-test without cutting power mid-sequence. Interrupting the BMS verification cycle during first boot can register a false battery fault that persists until the next clean reboot — let the device reach the main monitoring screen before doing anything else.
Why the M3 flags a battery fault after a confirmed full charge
The M3's BMS uses a learned capacity threshold calibrated to the previous cell's charge history. A new cell arrives with no cycle data, so the BMS may flag it as underperforming even at full charge voltage. This clears after one complete charge-discharge cycle, which lets the BMS write a baseline to its registers. Until that cycle is complete, the fault flag is a calibration artefact — not a defective battery.
M3 not completing boot sequence after battery sat in storage
Li-ion cells self-discharge during storage, and the M3's BMS has a minimum recovery threshold — typically around 10.0–10.5V for a 14.8V nominal pack — below which it blocks power delivery entirely. If the battery shipped or sat unused long enough to drop below that threshold, the monitor won't boot even though the cell isn't dead. Connect the battery to the M3 on mains power and leave it on charge for at least 30 minutes before attempting to power on — the charge IC will trickle the cell back above the BMS recovery floor first.