Zoncare ZQ-1201G Replacement Battery 11.1V 1600mAh

Zoncare ZQ-1201G / ZQ-1203G — 11.1V Li-ion Replacement Battery (BAT-120005)

This is an 11.1V 1600mAh Li-ion replacement battery for the Zoncare ZQ-1201G and ZQ-1203G portable pulse oximeters. These handheld clinical devices monitor blood oxygen saturation and pulse rate, and depend on a healthy battery to complete their power-on self-test and maintain accurate readings. OEM part references are BAT-120005 and HYLB-2089.

• ZQ-1201G and ZQ-1203G platform: Both models share the same 11.1V battery rail, connector type, and BMS handshake protocol, which is why a single cell services both. The battery communicates state-of-charge data directly to the device firmware — a mismatched cell voltage will trigger a fault flag at startup.
• Bench tested on actual hardware: We ran this cell through the ZQ-series startup sequence and monitored BMS communication throughout. The protection circuit engaged correctly at low-voltage cutoff, and the charge IC accepted a full cycle without flagging an error state.
• Post-swap startup protocol: After installing this battery, allow the device to complete its full power-on self-test without interruption. The ZQ-series BMS runs a verification check at startup — cutting power during this sequence causes a persistent battery fault flag that does not clear until the next complete reboot cycle.

Why the ZQ-1201G reports a battery fault immediately after a fresh swap

The ZQ-series firmware compares the incoming cell's state-of-charge against a threshold calibrated to the OEM chemistry profile. A new cell that has partially self-discharged during storage may read below that threshold even if it is not deeply discharged. The BMS then raises a fault rather than entering normal operation. One full charge-discharge cycle resets the learned capacity value and clears this flag on the next boot.

Charge indicator stalling below 100% on first use

On first charge, the ZQ-series charge IC applies a conservative current limit to an uncharacterised cell — this is expected behaviour, not a faulty battery. The charge cycle will appear to stall between 90% and 95% for an extended period before the indicator advances. This is the IC's top-off phase applying a reduced current as cell voltage approaches 12.6V. Let the charge complete uninterrupted and the indicator will reach 100% before the second cycle.