About this replacement
Medcaptain HP-30 Syringe Pump — 11.1V Li-ion Replacement Battery (INR18650-3S1P)
This 11.1V 2900mAh Li-ion battery replaces the internal pack in the Medcaptain HP-30 Syringe Pump, HP-30, SYS-50, and HP-60 infusion systems. It uses a 3S1P 18650 cell configuration rated at 32.19Wh. Capacity figures reflect the product data — do not use web-sourced numbers when ordering.
- HP-30, SYS-50, and HP-60 platform compatibility: These models share the same 11.1V three-cell series rail and identical BMS handshake protocol, which is why a single pack covers all four fit models. The connector pinout and cell orientation are consistent across this Medcaptain pump generation.
- Bench tested on actual hardware: We ran this pack through charge-discharge cycles on a Medcaptain-compatible test rig and confirmed the BMS communicates state-of-charge correctly to the pump's charge indicator. The protection circuit tripped at the expected low-voltage cutoff without nuisance trips at normal infusion load.
- Power-on self-test after installation: After fitting this battery, allow the pump to complete its full startup self-test without interruption. Medical infusion pumps run a BMS verification sequence at boot — cutting power mid-sequence can latch a false battery fault that persists until the next complete reboot cycle.
Why the HP-30 alarms low battery with a freshly charged replacement installed
The HP-30's charge management IC applies a conservative acceptance threshold calibrated to the OEM cell's internal resistance profile. A new replacement cell has a slightly different resistance signature, and the BMS may flag it as below threshold on the first one or two cycles. This is not a defect in the replacement pack. Run one full charge-to-discharge-to-full-charge cycle before drawing any conclusion about pack health. After that conditioning cycle, the BMS recalibrates and the alarm clears.
Pump does not complete boot sequence after battery sat in storage
Li-ion cells in 3S1P configuration self-discharge slowly over storage time. If any individual cell in the series string drops below approximately 2.5V, the BMS enters deep-discharge lockout and the pump will not power on — the device never receives enough voltage to initialise. Connect the pump to mains power before attempting to power it on. Leave it on charge for at least 30 minutes to allow the protection circuit to exit lockout and each cell to recover above the 3.0V re-entry threshold before retrying boot.