Zoncare iMAC 300 Replacement Battery 14.8V 1750mAh WP-BTQ-09

Zoncare iMAC 300 — 14.8V Li-Polymer Replacement Battery (WP-BTQ-09)

This 14.8V Li-Polymer battery replaces the OEM WP-BTQ-09 cell in the Zoncare iMAC 300 portable cardiac monitor. Capacity is 1750mAh (25.9Wh). It fits the iMAC 300's battery bay and connects to the same BMS communication bus used by the original pack.

• iMAC 300 platform fit: The iMAC 300 uses a 14.8V four-cell Li-Polymer configuration with a dedicated BMS handshake. This replacement matches that voltage rail and cell count, so the device's charge IC and battery management controller see a valid pack on insertion.
• Bench tested on actual hardware: We cycled this pack under a load profile that replicates continuous ECG acquisition and display. The BMS held cell balance across all four cells and triggered protection thresholds at expected voltages — no premature cutoff on discharge, no charge IC rejection at the start of the charge cycle.
• Post-swap startup sequence: After installing a fresh pack, let the iMAC 300 complete its full power-on self-test without interruption. The device runs a BMS verification routine at boot. Interrupting this sequence — even briefly pressing the power key — can trigger a persistent false battery fault that will not clear until the next complete reboot.

Why the iMAC 300 charges a new pack to less than 100% on the first cycle

The iMAC 300's charge IC applies a conservative initial charge ceiling when it first sees a new cell chemistry signature. This is standard behaviour for medical-grade charge controllers — the IC limits current and top-of-charge voltage until it has logged one complete cycle. The pack is not defective. Run one full discharge to the device's low-battery cutoff, then charge uninterrupted to completion. After that first full cycle, the charge IC releases the ceiling and the indicator will reach 100%.

iMAC 300 will not power on after the replacement battery sat uninstalled in storage

Li-Polymer cells self-discharge during storage. If the pack voltage has dropped below approximately 12.0V (3.0V per cell), the iMAC 300's BMS will block startup as a deep-discharge protection measure. Connect the battery to the device and leave it on charge for at least two hours before attempting to power on — most medical-grade charge ICs include a pre-charge trickle mode that recovers cells in this range. If the device still does not respond after two hours on charge, check that the charger is delivering voltage to the pack by confirming the charge LED is active on the device itself.