About this replacement
Tosight DW-6000 / DWK-6000 — 7.2V Ni-MH Replacement Battery
This is a 7.2V 2600mAh Ni-MH replacement battery for the Tosight DW-6000 and DWK-6000 surveying and measurement instruments. It matches the original pack's voltage, capacity, and form factor at 71.90 × 65.76 × 17.14mm. Capacity is rated at 18.72Wh, consistent with the OEM specification for both models.
- DW-6000 and DWK-6000 compatibility: Both models share the same battery bay dimensions, 7.2V power rail, and internal BMS handshake requirements. The cell count and series configuration are identical across both variants, so one pack covers either instrument without modification.
- Bench tested on actual hardware: We ran this pack through probe initialisation cycles and sustained sensor logging loads. The BMS held stable across repeated power-up current spikes without tripping into protective cutoff, and voltage recovery after load drop stayed within the instrument's acceptance window.
- First-use calibration cycle: After installing this pack, run a full calibration cycle through the instrument's menu before field deployment. The DW-6000 maps battery state during that calibration sequence. Skip it and the instrument's low-battery threshold will be miscalibrated to the old cell's degraded voltage curve, triggering false low-battery warnings early in your first measurement session.
BMS lockout after the DW-6000 sat unused in a carry case for months
Ni-MH packs self-discharge at roughly 1–2% per day at room temperature. After several months in storage, the cell voltage can drop below the BMS's recovery threshold — typically around 0.9V per cell in a six-cell 7.2V pack. At that point the BMS enters a protective sleep state and the instrument shows no power response at all, even when the charger is connected. Place the pack on the charger and leave it for a minimum of 30 minutes before attempting to power on the instrument; most BMS circuits require a slow trickle input to exit sleep mode before accepting a standard charge current.
Readings drifting or logging session resetting mid-capture
This happens when sustained sensor load pulls the pack voltage low enough that the instrument's internal regulator briefly drops out of its operating range. It is not a full shutdown — the instrument resets the active logging session and restarts the sensor module. The cause is usually a pack with degraded cells that cannot hold voltage under continuous draw, even if the charge indicator shows adequate capacity at idle. Charge the pack fully, then check idle voltage with a multimeter — a healthy 7.2V Ni-MH pack should read between 8.4V and 8.6V immediately after a full charge cycle.