Edan F2 Patient Monitor Compatible Battery 14.8V 5200mAh

Edan F2 / F3 / IM8 Series — 14.8V Li-ion Replacement Battery (01.21.064142)

This is a 14.8V, 5200mAh Li-ion battery that replaces OEM part numbers 01.21.064142, 01.21.064143, TWSLB-002, and TWSLB-003. It fits the Edan F2 and F3 patient monitors, IM8 and IM8F multipara monitors, and nine additional compatible models. Voltage and capacity match the original specification exactly.

• F2 / F3 / IM8 platform fit: These models share a common 14.8V four-cell Li-ion architecture with the same battery bay dimensions, connector pinout, and BMS communication protocol — which is why a single cell pack covers the full range. The BMS on each device reads cell voltage across all four series cells and will reject a pack that doesn't sit within the expected voltage window at startup.
• Bench tested on actual hardware: We cycled this pack through a full charge and discharge sequence under a simulated patient-monitor load profile. The BMS completed its cell-balance handshake without fault codes, and the protection circuit responded correctly to both over-current and over-temperature conditions.
• Post-swap self-test protocol: After installing this battery, let the F2 or IM8 complete its full power-on self-test cycle before attaching it to a patient. These monitors run a BMS verification routine at every boot — interrupting it before the cycle finishes can latch a battery fault flag that won't clear until the next clean reboot.

Why the F2 alarms low battery immediately after a confirmed full charge

The F2's charge IC applies a conservative current limit on the first charge of a new or long-stored cell, which can result in the pack not reaching the BMS's minimum acceptance threshold. The device reads state-of-charge from the BMS, not from a simple voltage check — so even if the charger indicator shows complete, the BMS may not yet accept the cell as fully conditioned. Running one complete charge-to-discharge-to-charge cycle resolves this in most cases. After the first full cycle, the BMS recalibrates its capacity estimate and the low-battery alarm stops triggering at full charge.

Monitor will not power on after battery sat in storage

Li-ion cells self-discharge during storage, and if any cell in the four-cell series pack drops below approximately 2.5V, the BMS locks the output to prevent damage — the device appears completely dead. The F2 and IM8 will not boot at all when the BMS is in this protective lockout state. Connect the battery to the OEM charger and leave it for at least 30 minutes without interruption — the charger applies a trickle pre-charge current that recovers cells above the BMS unlock threshold. Once each cell reads above 3.0V, the BMS releases the output lock and the device will power on normally.