CPLD-336 Medion Life P5001 Replacement Battery 3.8V 2000mAh

Medion Life P5001 — 3.8V Li-Polymer Replacement Battery (CPLD-336)

This 3.8V, 2000mAh Li-Polymer battery replaces the CPLD-336 cell in the Medion Life P5001 smartphone (also listed as MD 98664 and Smartphone P5001). It restores power to phones where the original cell has degraded, swollen, or stopped holding a charge. Capacity is 2000mAh (7.6Wh) — matching the original specification.

• P5001 and MD 98664 fitment: These model numbers share the same battery bay dimensions (68.50 × 54.90 × 4.00mm), the same 3.8V nominal voltage rail, and the same three-contact connector pinout — so one cell covers the full variant range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the P5001 board. The BMS handshake completed correctly, charge current ramped as expected, and the protection circuit tripped cleanly at low-voltage cutoff without needing a manual reset.
• Fuel gauge recalibration on first cycle: After fitting this cell, disable fast charging and run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the fuel gauge IC a complete reference curve against the new cell before high-current charging begins.

Sudden shutdown at 20–30% on the P5001 after a cell swap

A new Li-Polymer cell has a slightly different discharge curve than the worn cell the fuel gauge IC was calibrated against. When the modem transmits or the screen brightness spikes, current draw rises sharply and the cell voltage drops faster than the IC expects — triggering a low-voltage shutdown even though the displayed percentage still reads mid-range. This is a calibration gap, not a faulty cell. One complete discharge-to-shutdown followed by a full uninterrupted charge resets the coulomb counter reference. After that cycle, the reported percentage should track accurately down to around 3.5V before shutdown.

Phone stays on the boot logo and won't complete startup after storage

If the replacement cell shipped in a low state of charge and sat in storage, the cell voltage may have dropped below the BMS lockout threshold — typically 2.5V per cell for Li-Polymer. The P5001 draws enough current on boot to collapse the voltage further, causing the board to reset in a loop. Connect the phone to a 5V charger and leave it for 20–30 minutes without attempting to power on — this allows the charge IC to trickle current into the cell and bring it above the BMS recovery threshold. Once the charging indicator appears on screen, the cell has cleared lockout and a normal boot will complete.