Palm Treo 600 CA4TREO600 Replacement Battery 3.7V 2000mAh

Palm Treo 600 / Treo 610 — 3.7V Li-ion Replacement Battery (CA4TREO600)

This is a 3.7V, 2000mAh Li-ion replacement cell for the Palm Treo 600 and Treo 610 smartphones. It fits the original battery bay and connects to the same internal contacts. Use the capacity from the product data: 2000mAh at 7.4Wh.

• Treo 600 and 610 shared platform: Both models run the same battery bay dimensions, voltage rail, and connector pinout. The 610 is a regional carrier variant of the 600 with no electrical differences at the battery interface — the same cell services both.
• Bench tested on actual hardware: We ran the cell through the Treo 600's charge IC and confirmed the BMS communicates correctly across a full charge cycle. Charge acceptance was normal and no overcurrent trips were triggered during the initial load test.
• Fuel gauge recalibration on first install: On first use, disable any fast-charge accessory and run one complete discharge-to-charge cycle before normal use. This allows the fuel gauge IC to map the new cell's discharge curve before the charge IC pushes higher current into an uncalibrated cell.

Sudden shutdown at 20–30% on the Treo 600 after a cell swap

This is a voltage cliff issue. Under GSM modem load or backlight spikes, the cell voltage drops faster than the fuel gauge IC expects based on the old cell's curve. The phone reads 25% remaining but the actual cell voltage falls below the shutdown threshold. One full discharge and recharge cycle lets the coulomb counter recalibrate against the new cell. After that cycle, the reported percentage tracks actual capacity accurately.

Treo 600 not powering on after sitting in storage with a flat battery

If a Li-ion cell discharges below approximately 2.5V during extended storage, the BMS enters lockout to prevent a damaged cell from accepting charge current. The Treo 600's charge IC will not begin a normal charge cycle from this state. Connect the device to a wall charger — not a USB port — and leave it for 20–30 minutes without pressing the power button. The charge IC uses a trickle pre-charge mode to bring the cell back above the BMS re-enable threshold, typically around 2.9V, before switching to standard charge current.