Welch-Allyn PIC30 Replacement Battery 12V 3700mAh Ni-MH

Welch-Allyn PIC30 / PIC40 / PIC50 — 12V Ni-MH Replacement Battery (001647-U)

This is a 12V 3700mAh Ni-MH battery for the Welch-Allyn PIC30, PIC40, and PIC50 portable vital signs monitors, as well as the MRL Defibrillator PIC30. It replaces OEM part numbers 001647-U and 10N-4000AA. The PIC30 series runs on AC in fixed locations and switches to this battery during patient transport or when wall power is unavailable.

• PIC30 / PIC40 / PIC50 platform fit: These three monitors share the same battery bay dimensions, voltage rail, and connector pinout. The BMS in each unit applies the same NiMH charge profile and reports state-of-charge identically, so one cell SKU covers the full series without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a PIC30 unit. The BMS accepted the cell on first insertion, completed charge without fault flags, and the state-of-charge readout stabilised after one full cycle.
• Post-swap self-test protocol: After installing this battery, allow the PIC30 to complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power during this sequence registers a battery fault that persists until the next clean reboot.

Device not completing boot sequence after battery swap

The PIC30 runs a hardware and BMS verification check during every startup. If the incoming cell voltage is below approximately 10.8V — common after storage — the BMS interprets it as a degraded or incompatible cell and halts the boot sequence before the main UI loads. This is not a fault with the replacement battery. Connect the device to AC power and allow it to charge the new cell for a minimum of two hours before attempting a battery-only boot. Once voltage recovers above threshold, the self-test completes normally.

Charge indicator not reaching 100% on first charge

The PIC30 charge IC applies a conservative current limit on cells it has not yet profiled. On the first charge cycle with a new cell, the indicator may plateau at 85–90% and stall. This is the charge controller applying a reduced termination threshold until it establishes a baseline for the cell's internal resistance. Run one complete charge-discharge cycle with the device connected to AC, then repeat the full charge. The indicator reaches 100% consistently from the second cycle onward.