Stryker 110562-U 8.4V Ni-MH Compatible Battery 211-22

Stryker 211-22 Power Pack Interpulse — 8.4V Ni-MH Replacement Battery (110562-U)

This is an 8.4V, 3000mAh Ni-MH replacement battery for the Stryker 211-22 Power Pack Interpulse. It carries OEM part number 110562-U and is a direct fit for that specific power pack model. Voltage, connector, and cell count match the original specification.

• 211-22 Power Pack Interpulse compatibility: The 211-22 uses an 8.4V Ni-MH chemistry specifically because its BMS is calibrated to the charge curve and internal resistance profile of NiMH cells. Substituting a different chemistry — even at the same voltage — will trip a false fault on this platform.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the 211-22 platform and confirmed the BMS completed its verification handshake without fault codes. The pack accepted a full charge and the state-of-charge indicator advanced correctly through each stage.
• Post-swap self-test protocol: After installing this battery, allow the 211-22 to complete its power-on self-test without interrupting or powering down the unit. The BMS runs a cell verification routine at startup — cutting power mid-sequence stores a false battery fault that persists until the next full, uninterrupted reboot.

Why the 211-22 flags a battery fault after the first charge cycle

The 211-22 BMS was set by Stryker to pass cells that match a known internal-resistance baseline. A new Ni-MH cell starts life with slightly elevated internal resistance until the chemistry stabilises through its first full charge-discharge cycle. If the BMS runs its verification before that first cycle is complete, it compares the new cell's resistance reading against the baseline and logs a conditional fault. One complete charge-to-discharge cycle — not partial — brings the cell into range and clears the flag on the next power-on test.

211-22 shuts off mid-use before the battery indicator reads low

This is a load-profile issue in the first ten cycles of a new Ni-MH cell. The 211-22 draws current in pulses during active use, and a new cell's voltage sags further under each pulse than a conditioned cell. When that sag briefly crosses the BMS undervoltage threshold, the unit cuts out even if the resting state-of-charge still reads mid-range. The fix is to run the pack through three to five full charge-discharge cycles before clinical use — this reduces the sag delta and keeps pulse loads above the 7.2V cutoff the BMS enforces.