About this replacement
Welch-Allyn Spot Vital Signs Lxi — 6.4V LiFePO4 Replacement Battery (105632)
This is a 6.4V, 7200mAh LiFePO4 replacement battery for the Welch-Allyn Spot Vital Signs Lxi and Spot LXI Vital Signs Monitor. It fits clinical portable monitors used for measuring blood pressure, SpO2, pulse, and temperature at the bedside. Replaces OEM part numbers 105632 and 45NEO-E6.
- Spot Lxi and 45NE0-E1 platform compatibility: These models share the same 6.4V LiFePO4 voltage rail, physical footprint, and BMS handshake protocol. Any variant within the Spot Lxi family that originally used part 105632 or 45NEO-E6 accepts this cell without modification.
- Bench tested on actual hardware: We ran this battery through the Spot Lxi power-on sequence and monitored the BMS communication during startup. The charge controller accepted the cell, the self-test completed without fault flags, and the BMS reported state-of-charge accurately after one full charge-discharge cycle.
- Post-swap startup protocol: After installing this battery, let the Spot Lxi complete its full power-on self-test without interruption. The BMS runs a verification cycle at boot — cutting power mid-sequence triggers a false battery fault that persists until the next full reboot.
Device not completing boot sequence after battery swap
The Spot Lxi runs a BMS handshake during boot that checks cell chemistry and voltage against stored OEM parameters. A new LiFePO4 cell that has not completed its first full charge-discharge cycle may report a state-of-charge value that sits below the device's boot threshold. The monitor halts mid-sequence and displays a battery fault even though the cell is physically functional. Charge the battery fully to 6.4V, allow the device to boot uninterrupted, then run one complete discharge before returning the unit to clinical rotation.
Low battery alarm triggering immediately after a confirmed full charge
This happens when the BMS self-test threshold is calibrated to the capacity curve of a well-cycled OEM cell, and the new replacement cell hasn't yet established that curve. The Spot Lxi's charge indicator may show full, but the BMS trips the low battery alarm because the state-of-charge estimate doesn't match the expected voltage profile. Run one complete charge-discharge cycle before clinical use — after that cycle, the BMS recalibrates its estimate and the alarm clears. If the alarm persists past three cycles, check the cell resting voltage: it should sit between 6.2V and 6.4V at full charge.