About this replacement
UTECH UTMI Patient Monitor — 11.1V Li-ion Replacement Battery (JW-Y3S-4.4)
This 11.1V, 5200mAh Li-ion battery replaces the original pack in the UTECH UTMI Patient Monitor and PM5000 monitor. It supplies the sustained, clean power draw these devices require to track vital signs at the bedside or during transport. Voltage and cell count match the OEM specification exactly.
- UTMI and PM5000 compatibility: Both monitors share the same battery bay dimensions, connector pinout, and BMS communication protocol — a single cell configuration at 11.1V (3S) covers both. Swapping between units does not require reconfiguration.
- Bench tested on actual hardware: We ran this pack through charge-discharge cycles on the PM5000 platform and confirmed the BMS handshake completed without fault codes. The protection circuit responded correctly to overcharge and over-discharge thresholds during testing.
- Post-swap self-test requirement: After installation, allow the monitor to complete its full power-on self-test without interruption. The device runs a BMS verification routine at startup — cutting power during this sequence triggers a persistent false battery fault that will not clear until the next complete reboot cycle.
Device not completing boot sequence after battery swap
Patient monitors like the UTMI run a BMS learn cycle during the first few charge-discharge passes on a new cell. Until that cycle completes, the onboard charge IC applies conservative capacity estimates, which can cause the boot sequence to stall or halt at the battery check screen. This is not a fault with the replacement pack — it is the device calibrating to the new cell chemistry. Run one full charge to completion, then discharge the monitor through normal use before returning it to clinical rotation. After that first full cycle, boot behaviour returns to normal.
Charge indicator not reaching 100% on first charge
On the first charge after installation, the PM5000 and UTMI monitors frequently show the charge indicator stalling at 90–95% and not advancing. The charge IC defaults to a reduced current limit on unrecognised cell chemistry until the BMS completes its initial verification pass. Leave the device on charge past the point where the indicator stalls — the IC will complete a top-off trickle charge and the indicator will step to 100% once the BMS clears the new-cell flag. Do not interrupt this first charge. After one full cycle the charge curve normalises and the indicator will reach 100% at the standard rate.