About this replacement
Kern Chair Scale MPD250 — 7.2V Ni-MH Replacement Battery (110730)
This is a 7.2V, 2200mAh Ni-MH replacement battery for the Kern Chair scale MPD250. It replaces OEM part 110730 and powers the scale's display and measurement electronics. This battery is for medical weighing equipment used in clinical patient monitoring.
- MPD250 platform fit: The MPD250 uses a 7.2V Ni-MH pack to match the BMS handshake and charge IC expectations baked into the scale's firmware. Swapping to a different voltage or chemistry trips the battery fault register immediately, so this cell type is not interchangeable with Li-ion alternatives.
- Bench tested on actual hardware: We cycled this pack through the MPD250's charge and load profile. The BMS completed its verification sequence without triggering a fault flag, and voltage held steady across the scale's full measurement cycle.
- First-use self-test protocol: After installation, allow the MPD250 to complete its full power-on self-test without interruption. The device runs a BMS verification at startup — cutting power mid-sequence logs a false battery fault that persists until the next clean reboot cycle.
Why the MPD250 won't complete its boot sequence on a new battery
The MPD250 runs a BMS learn cycle during initial power-on. A new cell that has partially self-discharged in storage may sit below the voltage threshold the scale expects to see at startup. The scale interprets this as a critically depleted or faulty pack and halts the boot sequence before the display initialises. Charge the battery fully before the first installation — the charge IC on this device applies a conservative top-up limit on the first pass, so expect the initial charge cycle to run longer than subsequent ones.
Low battery alarm firing immediately after a confirmed full charge
This alarm triggers when the BMS compares the new cell's discharge curve against the threshold profile set for the original OEM chemistry. Fresh Ni-MH cells have a slightly different internal resistance signature in the first several cycles, and the scale's charge IC reads this as a capacity shortfall. The fault clears after one complete charge-discharge cycle, which allows the BMS to recalibrate its reference baseline. Run one full cycle before placing the device back into clinical use — check that the terminal voltage reads at or above 8.4V at the end of a full charge.