Wacom GWL-001 Graphire Wireless Pen Replacement Battery 3.7V 1700mAh

Wacom CTE630BT Graphire Wireless Pen Tablet — 3.7V Li-ion Replacement Battery (GWL-001)

This is a 3.7V, 1700mAh Li-ion replacement battery for the Wacom Graphire Wireless Pen Tablet. It fits the CTE630BT, CTE-630BT, and CTE-620BT wireless stylus systems. The GWL-001 cell powers the wireless pen unit itself — not the tablet base — restoring full wireless input functionality when the original cell has degraded.

• CTE630BT and CTE-620BT pen compatibility: Both models use the same 3.7V single-cell architecture and GWL-001 form factor. The pen's internal BMS accepts the same voltage rail and physical footprint across the Graphire wireless range, so one SKU covers all listed variants.
• Bench tested on actual hardware: We ran the GWL-001 replacement through charge cycles on the Graphire wireless pen and confirmed the BMS accepted charge handshake without triggering protection cutoff. Voltage settled correctly at 4.2V at full charge.
• Pen stylus storage tip: If the wireless pen has been stored uncharged for more than a few months, the cell may sit below the BMS recovery threshold. Place it in the charging dock for at least 20 minutes before testing — this gives the protection circuit enough voltage to re-engage and allow a normal charge cycle to begin.

Why the Graphire wireless pen stops registering mid-session

The Graphire wireless pen draws current in bursts — each time the nib makes contact with the tablet surface, the pen transmits a short RF signal. As the original cell ages, its internal resistance rises. Under those burst loads, voltage sags enough to drop below the BMS cutoff even when the pen appears charged. The result is intermittent drop-outs during drawing strokes rather than a clean power-off. Replacing the cell eliminates the high-resistance drop and restores stable burst delivery.

Pen shows a full charge but dies after light use

This is fuel gauge drift — the pen's charge indicator is calibrated against the old cell's discharge curve, not the new one. After fitting the replacement, run one full discharge until the pen stops responding, then charge it uninterrupted to 100%. That single cycle forces the gauge IC to recalibrate its reference points against the new cell's actual capacity, and the charge readout will stabilise from that point forward.