EXFO FTB-1 Compatible Battery 14.4V 2600mAh Li-ion

EXFO FTB-1 / MAX-860 Series — 14.4V Li-ion Replacement Battery (FTB-1LO4D318A)

This 14.4V 2600mAh (37.44Wh) lithium-ion battery replaces the OEM pack in the EXFO FTB-1, FTB-1v2, FTB-1v2-PRO, and MAX-860 modular test platforms. These instruments are used for fiber optic network surveying and field measurements where a dead battery mid-session means lost data and wasted site visits. The OEM part numbers covered are FTB-1LO4D318A, LO4D318A, XW-EX009, GP-2252, and GP-2253.

• FTB-1 and MAX-860 platform compatibility: These models share the same 14.4V battery rail, physical form factor (149.30 × 41.00 × 23.20mm), and BMS handshake protocol — which is why a single pack covers the FTB-1, FTB-1v2, FTB-1v2-PRO, and MAX-860 without modification.
• Bench tested on actual hardware: We cycled this pack through the FTB-1 power management system under optical module load. The BMS responded correctly to charge termination and discharge cutoff at the expected voltage thresholds without tripping fault flags.
• Pre-deployment calibration cycle: After fitting this battery, run a full calibration cycle through the instrument's system menu before going on site. The FTB-1 maps battery state during calibration — skipping this step causes premature low-battery warnings on the first measurement session, even when the pack is fully charged.

Why the FTB-1 shuts down when an optical module initialises

When the FTB-1 powers up an inserted test module, there is a brief current spike as the module's internal circuits initialise. A degraded or poorly matched battery pack can sag below the platform's minimum operating voltage at that exact moment, triggering a protective shutdown before any measurement begins. This is a BMS-level event — the instrument interprets the voltage drop as a fault condition, not a low battery. A fresh pack with healthy cell internal resistance handles the initialisation spike without dropping below threshold.

Battery percentage jumping or resetting after reboot

The FTB-1 estimates state of charge by comparing resting cell voltage against a stored lookup table calibrated to the OEM cells. A new pack with slightly different resting voltage curves will read as a different percentage than expected on the first few boots, often jumping erratically. This settles after one or two full charge-discharge cycles as the instrument recalibrates its threshold mapping to the new cells. Run the pack down to the automatic cutoff once, then charge fully to 16.8V before the next field session.