EXFO GP-2209 MAX-700 Compatible Battery 3.7V 10000mAh

EXFO MAX-700 / MAX-900 Series — 3.7V Li-Polymer Replacement Battery (GP-2209)

This 3.7V 10000mAh Li-Polymer pack replaces the GP-2209 battery in the EXFO MAX-700, MAX-700B/C, MAX-900, and MAX-900FIP optical power meters and light source testers. It fits the same battery bay and connector used across this series. Capacity is drawn from product data at 37Wh.

• MAX-700 and MAX-900 platform compatibility: Both series share the same 3.7V single-cell Li-Polymer architecture, bay dimensions, and BMS handshake protocol — that is why one pack covers multiple units in the line. The connector pinout and charge-termination signal are identical across MAX-700, MAX-700B/C, MAX-900, and MAX-900FIP.
• Bench tested on actual hardware: We ran this pack through charge, discharge, and probe-power-up cycles on the MAX-700 platform. The BMS accepted the new cell without fault codes, and the charge-termination handshake completed cleanly at 4.2V under the instrument's onboard charger.
• First-use calibration before field deployment: After fitting this pack, run a full calibration cycle through the instrument's menu before heading to site. The MAX-700 and MAX-900 map battery state during that calibration pass — skip it and the low-battery indicator will trigger early on your first measurement session, even with a full charge.

MAX-700 and MAX-900 shutting down mid-measurement with a charged battery showing

The MAX-700's optical module draws a short current spike each time a probe or port initialises — enough to trip the BMS undervoltage threshold if the cell is aged or the pack is cold. The instrument reads a healthy percentage on screen, then cuts out without warning during the measurement pass. This is a BMS protection event, not a firmware fault. A new cell with full charge capacity handles the initialisation spike without hitting the cutoff floor.

Pack will not charge after the instrument sat unused in a carry case for months

Li-Polymer cells that self-discharge below roughly 2.5V per cell enter a deep-discharge state — the BMS locks the charge FET to prevent thermal runaway on a damaged cell. The EXFO charger circuit sees a locked pack and stops trying, leaving the indicator light unresponsive. A replacement pack bypasses this entirely. If you want to attempt recovery on the old pack first, a bench charger with a Li-Po recovery mode can trickle charge at 0.1C up to 3.0V before handing back to the instrument's onboard charger.