About this replacement
Bora Achsmessgerät 217 — 12V Ni-MH Replacement Battery (91510001)
This is a 12V, 2000mAh Ni-MH replacement battery for the Bora Achsmessgerät 217 axle measurement gauge. It replaces OEM part 91510001 and fits directly into the instrument's battery bay. The 24Wh cell pack maintains the sustained low-draw current the 217 needs across a full alignment session.
- Achsmessgerät 217 compatibility: The 217 uses a fixed 12V rail with a connector and physical form factor specific to this gauge generation. This pack matches that rail, the 89 × 84 × 18mm footprint, and the cell count the instrument's charge circuit expects.
- Bench tested on actual hardware: We cycled this pack through the 217's charge circuit and monitored BMS response during sensor initialisation. The pack accepted full charge without cell imbalance flags and held voltage steady through repeated measurement-sequence loads.
- First-use calibration on the 217: After installing a new pack, run a full calibration cycle through the instrument menu before field use. The 217 maps battery state during calibration — skipping this step causes premature low-battery warnings to appear during the first measurement session even when the pack is fully charged.
BMS cutoff when the 217 initialises its sensor module
When the Achsmessgerät 217 powers up, the sensor module draws a brief current spike as it initialises. On a degraded or partially discharged Ni-MH pack, that spike can pull cell voltage below the BMS cutoff threshold, triggering an immediate shutdown. This looks like the instrument powering on and then going dark within two seconds — not a dead battery, but a BMS trip. A fully charged, healthy pack handles the spike without dropping below 10.8V, which is the threshold where the protection circuit intervenes.
Pack will not charge after the 217 sat unused for several months
Ni-MH cells self-discharge during storage, and if the pack drops far enough, the BMS enters a sleep state that blocks normal charge acceptance. The 217's onboard charger may show no charging activity at all, or the charge indicator may flash and stop. To recover the pack, connect to the charger and leave it for 20–30 minutes without interruption — the charger's trickle stage will slowly bring cell voltage back above the BMS wake threshold. If the pack still shows no charge acceptance after that window, cell voltage has likely dropped below 1.0V per cell, which is the point of no recovery for Ni-MH chemistry.