Plum E700 Replacement Battery 3.7V 1550mAh PM-BATE700

Plum E700 / RAM 7 — 3.7V Li-Polymer Replacement Battery (PM-BATE700)

This is a 3.7V, 1550mAh (5.74Wh) lithium-polymer cell built to fit the Plum E700 and RAM 7 smartphones. It replaces OEM part number PM-BATE700 directly. If your original battery swells, refuses to hold charge, or causes unexpected shutdowns, this cell restores normal operation.

• E700 and RAM 7 shared platform: Both models run the same battery bay dimensions — 69.80 × 40.00 × 5.80mm — and use the same connector pinout and BMS handshake protocol. One cell fits both without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on E700 hardware. The BMS accepted the cell without a protection trip, and the charge IC stepped through CC/CV phases as expected with no thermal events.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging is applied to an uncalibrated cell — preventing erratic percentage readings from the first day.

Sudden shutdown at 20–30% on the Plum E700 after a cell swap

This is a voltage cliff failure, not a capacity problem. The fuel gauge IC on the E700 was calibrated to the discharge curve of the original cell. When the new cell's voltage drops faster under modem or display load than the IC expects, it reads the remaining capacity as higher than actual — until the cell hits the BMS low-voltage cutoff and the phone shuts off. One full discharge-to-shutdown followed by a complete charge resets the coulomb counter and re-anchors the gauge to the new cell's curve. After two or three full cycles, the percentage reading stabilises and the shutdowns stop.

Phone won't power on after sitting in storage with a flat battery

If the cell discharged below approximately 2.5V during storage, the BMS locks out to prevent damage from deep discharge. The phone will show nothing when you press the power button — no logo, no charging animation. Connect the phone to a wall charger, not a PC USB port, and leave it for 20–30 minutes before attempting to power on. The charge IC needs to deliver a low-current trickle to bring the cell above the BMS re-enable threshold, which sits around 2.8–3.0V, before normal charging and boot can proceed.