RedBack Laser CXR880 Replacement Battery 2.4V 3500mAh 880BAT

RedBack Laser CXR880 / DGL3000 — 2.4V Ni-MH Replacement Battery (880BAT / 3000BAT)

This is a 2.4V Ni-MH battery rated at 3500mAh (8.4Wh), replacing part numbers 880BAT and 3000BAT. It fits the RedBack Laser CXR880, DGL3000, DGL3000 laser level, and Unilevel rotary laser instruments. These are construction-grade rotary laser levels used for alignment and reference marking on site.

• CXR880, DGL3000, and Unilevel compatibility: All four fit models share the same 2.4V two-cell Ni-MH pack format, connector pinout, and BMS handshake protocol. Swapping between these instruments does not require adapters or firmware changes — the pack communicates state-of-charge the same way across the range.
• Bench tested on actual hardware: We cycled this pack through the CXR880's charge circuit and confirmed the BMS accepted charge termination correctly at full capacity. We also verified the pack delivers stable voltage across the sustained rotary motor and laser diode draw without triggering an undervoltage cutoff.
• Post-install calibration cycle: After fitting this pack, run a full calibration cycle through the instrument menu before field deployment. The CXR880 and DGL3000 map battery state during calibration — skipping this step causes premature low-battery warnings on the first measurement session, even with a fully charged pack.

BMS lockout after the instrument sat unused in a carry case for months

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A pack stored in a case for several months can drop below the BMS recovery threshold — typically around 1.8V per cell, or 3.6V across the two-cell pack. When this happens, the instrument's charge circuit may not initiate a charge cycle because the BMS is in sleep mode and not presenting a valid voltage to the charger. To recover the pack, place it on the charger and hold it there for up to 30 minutes — most chargers will begin a low-current trickle once the BMS wakes above 2.0V per cell and resumes normal communication.

Instrument powers on but shuts off during USB data transfer to PC

USB data transfer activates a second current path — the USB interface controller draws additional load on top of the laser and display. On a partially discharged or degraded original pack, this combined draw can pull the terminal voltage below the BMS cutoff threshold, triggering a shutdown mid-transfer. This is not a firmware fault — it is a voltage floor issue. Charge the pack fully before beginning any data transfer session and confirm terminal voltage is at or above 2.4V before connecting the USB cable.