About this replacement
Vernier Wireless Dynamics Sensor System — 3.7V Li-ion Replacement Battery (WDSS-BAT)
This 3.7V, 1800mAh Li-ion battery replaces the original WDSS-BAT pack in the Vernier Wireless Dynamics Sensor System. The WDSS is a wireless sensor unit used in physics and engineering labs to capture motion, acceleration, and force data during experiments. Voltage and capacity match the original specification so the sensor unit powers on and communicates normally with Vernier data collection software.
- WDSS compatibility: The Wireless Dynamics Sensor System runs its onboard accelerometer, force sensor, and Bluetooth radio from a single 3.7V cell. This pack matches that voltage rail and uses the same connector orientation and BMS handshake as the original WDSS-BAT, so the sensor unit recognises the pack without manual overrides.
- Bench tested on actual hardware: We cycled this pack through sensor initialisation and active wireless streaming. The BMS held stable under the combined radio and sensor load, and cutoff thresholds matched the original pack's behaviour at low-charge states.
- First-use calibration on the WDSS: After fitting the new pack, run a full zeroing and calibration cycle through Logger Pro or Graphical Analysis before your first data collection session. The WDSS maps battery state during that initialisation pass — skipping it causes the low-battery indicator to fire prematurely on the first experiment, interrupting data logging.
BMS cutoff when the WDSS force sensor or accelerometer initialises
At power-on, the WDSS pulls a brief current spike as both the force sensor and accelerometer come online simultaneously alongside the Bluetooth radio. If the battery cell is below roughly 3.5V, the BMS reads that inrush as an over-discharge event and trips the protection circuit before the device fully boots. This is not a faulty pack — it is the BMS doing its job on a low cell. Charge the pack fully to 4.2V before the first use and the initialisation spike will clear without tripping the cutoff.
WDSS not recognised after the pack sat unused for several months
Li-ion cells self-discharge during storage, and if the pack drops below approximately 3.0V the BMS enters sleep mode to prevent cell damage. In sleep mode the sensor unit sees no voltage on the battery rail and behaves as if no pack is installed. Connect the pack to a charger for at least 15–20 minutes — the charger's trickle current wakes the BMS, voltage climbs back above the recovery threshold, and the WDSS powers on normally. If the charger shows no activity after 30 minutes, the cell has dropped below recoverable voltage and the pack needs replacing.