About this replacement
Sony PSP E1000 Series — 3.7V Li-ion Replacement Battery (SP70C / 4-285-985-01)
This is a 3.7V, 900mAh Li-ion cell for the Sony PSP E1000 Street handheld gaming console. It also fits the E1002, E1004, and E1008 variants — all share the same battery bay dimensions and connector. Capacity figures come from the product data, not estimated specs.
- E1000 series compatibility: The E1000, E1002, E1004, and E1008 all use the same 45.08 × 34.92 × 6.50mm cell footprint with an identical three-pin connector and BMS handshake. Swapping between these models carries no electrical risk — the voltage rail and charge IC parameters are the same across the lineup.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a PSP E1000 unit. The console's charge IC accepted the cell without error, and the BMS protection triggers — overcurrent, overcharge, and undervoltage cutoff — all tripped at expected thresholds.
- Fuel gauge calibration after install: The PSP E1000 uses a simple coulomb-counting gauge that sets its empty reference point on the first full discharge. After installing this cell, run one complete play session to automatic cutoff without interrupting the discharge. This gives the gauge an accurate baseline for every subsequent charge reading.
Why the PSP E1000 shuts off before the battery indicator hits empty
The E1000 doesn't use a smart gauge IC — it estimates charge level from a stored discharge curve mapped to the original Sony cell. A replacement cell with a slightly different internal resistance will cause the console to misread remaining capacity. Under load spikes — UMD drive spin-up or heavy audio output — voltage dips briefly below the protection threshold, triggering a hard cutoff even when the gauge still shows bars. This is a firmware limitation in the charge-monitoring circuit, not a fault in the replacement cell itself.
Battery indicator jumping or reading incorrectly after a cell swap
After fitting a new cell, the PSP E1000's gauge often displays an inaccurate reading — jumping from full to one bar, or freezing mid-charge. This happens because the console's reference curve was calibrated to the original aged cell's discharge profile. Run the new cell through three to five full charge-and-discharge cycles; the gauge re-anchors its reference points against the actual cell behaviour with each pass. After conditioning, the indicator should track linearly down to the 3.0V cutoff.