About this replacement
Sony PRS-600 Series — 3.7V Li-Polymer Replacement Battery (A98927554931)
This is a 3.7V 800mAh Li-Polymer cell for the Sony PRS-600, PRS-600/RC, and PRS-600/BC e-readers. It replaces the original battery when years of charge cycles have reduced capacity to the point where the device no longer holds a usable charge. Dimensions are 63.52 × 34.12 × 3.65mm — measure your original cell before ordering.
- PRS-600 series fitment: The PRS-600, PRS-600/RC, and PRS-600/BC share the same battery bay dimensions, connector pin-out, and BMS handshake requirements. All three accept this cell without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the PRS-600 platform. The BMS accepted the cell without a fault flag, and the e-ink controller drew consistent current through full page-refresh cycles.
- Post-swap charge cycle: After fitting this battery, charge via USB until the on-screen indicator shows full before use. The PRS-600 firmware recalibrates its battery percentage display against a full charge reference — skipping this step causes the percentage counter to read erratically from the first session.
Why the PRS-600 shows low battery immediately after a new cell is installed
Replacement cells ship in storage mode, typically sitting between 3.6V and 3.7V. The PRS-600 firmware sets its low-battery warning threshold relative to a calibrated full-charge baseline it has not yet recorded for the new cell. Until the firmware completes one full charge cycle, it interprets the uncalibrated state-of-charge data as a near-empty cell. Connect the USB cable, let the device charge to 100%, and the warning clears on its own.
Battery percentage jumping around after a cell swap
The PRS-600 stores charge-curve data from the previous cell in firmware memory. When a new cell goes in, that stored curve no longer matches the actual cell behaviour, so the percentage reading jumps as the firmware tries to map old data to new voltage readings. This resolves through one or two full charge-and-discharge cycles, after which the firmware rewrites its curve data. If the jumping persists past two full cycles, verify the USB cable is delivering consistent 5V and not dropping mid-charge.