About this replacement
Laerdal LCSU4 Compact Suction Unit — 12V Ni-MH Replacement Battery (886113)
This is a 12V, 2000mAh Ni-MH replacement battery for the Laerdal LCSU4 Compact Suction Unit. It replaces OEM part numbers 886113 and B11651. The LCSU4 is a portable medical suction device used in clinical and emergency airway management.
- LCSU4 battery platform: The LCSU4 uses a dedicated 12V Ni-MH cell pack with a specific connector and BMS handshake. Voltage, cell count, and connector orientation all have to match — substituting a lithium cell or different form factor will trip the charge controller and leave the device in a permanent fault state.
- Bench tested on actual hardware: We ran this cell through the LCSU4 charge cycle and monitored BMS response at each charge stage. The protection circuit accepted the cell, completed charge termination at full capacity, and passed the device's power-on self-test without triggering a battery fault flag.
- First-use cycle for medical devices: After installation, let the LCSU4 complete its full power-on self-test without interrupting the sequence. The BMS runs a chemistry verification at startup — cutting power mid-sequence forces a false battery fault that persists until the next complete reboot and full charge cycle.
Why the LCSU4 BMS rejects a new cell on the first charge
Ni-MH charge controllers use delta-V termination — they watch for a voltage drop that signals full charge. A new cell has a flatter charge curve in the first two cycles, so the controller may not detect that termination point cleanly. The LCSU4's charge IC responds by applying a conservative current limit until the cell's internal resistance settles. One full charge-discharge cycle is usually enough for the BMS to calibrate against the new cell and charge normally.
Charge indicator stuck below 100% on the first charge
New Ni-MH cells shipped in partial-discharge state can cause the LCSU4's charge gauge to report an incomplete charge on the first fill. The charge IC sets a conservative upper threshold when it cannot verify the cell's history. Run one complete charge from flat to full — don't interrupt the cycle. After that first full cycle, the gauge should read correctly and charge termination voltage should stabilise near 14.4V.