EXFO PX1 Replacement Battery GP-2295 3.7V 1900mAh

EXFO PX1 Series — 3.7V Li-Polymer Replacement Battery (GP-2295)

This is a 3.7V, 1900mAh (7.03Wh) Li-Polymer battery that replaces OEM part GP-2295 in the EXFO PX1 Optical Power Expert platform. It fits the PX1, PX1-H-PRO-FOAS-U25, and PX1-S-PRO-FOAS-U25, along with related PX1 variants. The cell format matches the original at 71.30 × 39.60 × 6.20mm — no modification needed to seat it correctly.

• PX1 platform compatibility: All listed PX1 variants share the same 3.7V single-cell Li-Polymer rail, the same physical connector, and the same BMS handshake protocol. The GP-2295 form factor is consistent across the PX1 lineup, so one cell covers the full series without adapter or wiring changes.
• Bench tested on actual hardware: We cycled this cell through probe initialisation, sustained optical measurement logging, and USB data transfer simultaneously. The BMS held stable under the combined draw spike at probe power-up and did not trip into protection mode during the transfer session.
• Post-install calibration cycle: After fitting this battery, run a full calibration cycle from the PX1 instrument menu before heading into the field. The instrument maps battery state during that sequence — skipping it causes the low-battery indicator to fire early on the first measurement session, even with a full charge.

BMS lockout after the PX1 sat unused in a carry case for months

Li-Polymer cells self-discharge slowly during storage. If the PX1 sat unused long enough, the cell voltage can drop below the BMS recovery threshold — typically around 2.5V — and the protection circuit locks the pack out entirely. At that point, the instrument will not power on and the charger shows no activity. A slow-charge recovery using a compatible Li-Po charger set to trickle mode can bring the cell back above the recovery threshold. Once voltage climbs past 3.0V, the BMS re-initialises and normal charging resumes.

PX1 readings drift or reset mid-logging session

This is not a calibration fault — it is a voltage dropout under sustained sensor load. When the cell has degraded, internal resistance rises and the voltage sags under the continuous draw of an active logging session, even if the battery indicator looked fine at startup. The BMS interprets the sag as a low-voltage event and resets the measurement cycle to protect the cell. Fitting a fresh cell eliminates the sag; after installation, confirm resting voltage reads at or above 3.7V before starting a logging run.