JDSU GC724A Replacement Battery 11.1V 6700mAh Li-ion

JDSU GC724A / JD723A — 11.1V Li-ion Replacement Battery

This 11.1V, 6700mAh Li-ion pack replaces the internal battery in the JDSU GC724A and JD723A optical network test instruments. These are field-use units carried by telecom technicians during fiber optic installation, site surveys, and diagnostic testing. At 74.37Wh, this pack matches the original cell configuration and voltage rails the instrument expects.

• GC724A and JD723A compatibility: Both models share the same battery bay dimensions, 11.1V nominal rail, and BMS communication protocol. The connector pinout and cell count are identical across the two units, so one pack covers both instruments without modification.
• Bench tested on actual hardware: We cycled this pack through the GC724A's power-on and probe initialisation sequence. The BMS held stable through the current spike at module start-up and maintained cell balance across three full charge-discharge cycles.
• Instrument calibration after swap: After fitting this pack, run a full calibration cycle through the instrument menu before taking it into the field. The GC724A maps battery state during calibration — skip this step and the instrument will show premature low-battery warnings during your first measurement session, even with a full charge.

BMS cutoff during probe or module initialisation on the GC724A

When the GC724A powers up an optical probe or sensor module, the initialisation sequence pulls a sharp current spike — often 2–3× the steady operating draw. An aged or partially discharged original pack can't sustain that spike without voltage dropping below the BMS cutoff threshold. The instrument interprets this as a fault and shuts down, even though the battery indicator showed adequate charge a moment earlier. This pack's higher internal cell quality holds the voltage rail stable through that initialisation window, preventing nuisance cutoffs at power-up.

Readings drifting or logging session resetting mid-measurement

If the GC724A resets or drops a logging session without a full shutdown, the cause is usually a momentary voltage dropout under sustained sensor load — not a full BMS trip. The instrument's processor loses power long enough to reboot, but the battery recovers before the screen goes dark, so it looks like a software crash. Check the pack's resting voltage under no load — if it reads below 10.8V after a full charge, the cells are no longer holding capacity. A fresh pack at resting voltage of 12.3–12.6V will sustain the load without dropout.