Juniper Allegro CX VR-151 Replacement Battery 3.6V 3800mAh

Juniper Allegro CX VR-151 — 3.6V Ni-MH Replacement Battery (VSH-H11U)

This 3.6V, 3800mAh Ni-MH battery replaces the original pack in the Juniper Allegro CX VR-151 handheld field data collector. It also fits related GIS and GPS computer variants listed under part numbers VSH-H11U, 12523, and LHJBT-H11U. These units are used in field survey and equipment testing, where a dead battery means lost data and aborted sessions.

• Allegro CX and GIS/GPS computer compatibility: These variants share the same 3.6V cell architecture, connector pinout, and BMS handshake protocol. A single replacement pack covers the full platform without modification.
• Bench tested on actual hardware: We ran this pack through the Allegro CX power management cycle. The BMS responded correctly to charge termination, held the rated 3800mAh within tolerance, and showed no false low-battery cutoffs during sustained sensor polling loads.
• First-deploy calibration on the Allegro CX: After installing this pack, run a full calibration cycle through the Allegro CX system menu before going into the field. The unit maps battery state during calibration — skipping this step causes premature low-battery warnings during your first logging session.

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

Ni-MH cells self-discharge during storage, and the Allegro CX's BMS will not initiate a normal charge cycle if pack voltage has dropped below roughly 2.8V. At that point, the charger sees an out-of-range cell and refuses to engage. The fix is a low-current pre-charge — connect to the dock and hold the power button for 10 seconds to trigger the recovery handshake. Once the BMS accepts the pack and voltage climbs above 3.0V, normal charging resumes automatically.

Allegro CX shuts down mid-logging session with no low-battery warning

This happens when sustained sensor polling draws more current than a degraded or partially charged cell can sustain — voltage sags briefly below the BMS cutoff threshold and the unit powers off instantly. It is not a firmware fault and it does not log a battery error. Charge the pack fully until the dock indicator clears, then confirm the cell voltage reads at or above 3.6V under the system diagnostics screen before deploying. If shutdowns continue after a full charge, the original pack has degraded beyond recovery and replacement is the correct next step.