About this replacement
Pocketbook 611 Basic / 613 Basic New Series — 3.7V Li-Polymer Replacement Battery (MLP255085)
This 3.7V, 1500mAh Li-Polymer cell replaces the MLP255085 battery in the Pocketbook 611 Basic, 613 Basic New, Basic Touch 624, Touch Lux 623, and six additional models. At 90.20 × 49.30 × 3.60mm, it matches the original cell footprint so the back cover seats properly. Capacity figure is taken directly from product data — 1500mAh / 5.55Wh.
- Multi-model fit across the 600-series platform: These Pocketbook models share the same PCB connector, cell dimensions, and 3.7V voltage rail, which is why a single MLP255085 cell spans all of them. The BMS handshake is identical across the range, so the device firmware reads the new cell without modification.
- Bench tested on actual hardware: We ran this cell in a 611 Basic unit and confirmed the BMS accepted the charge cycle without throwing a fault, voltage at full charge held steady at 4.2V, and the display woke cleanly from sleep after the swap.
- First-cycle charging after swap: Pocketbook e-reader firmware recalibrates battery percentage against a full charge cycle. Connect via USB immediately after installing the new cell and let it charge completely before powering on — this gives the firmware an accurate baseline for the percentage indicator.
Why the 611 Basic shows incorrect battery percentage after a cell swap
The Pocketbook 611 Basic stores charge calibration data tied to the original cell's discharge curve. When a new cell goes in, that stored data no longer matches reality, so the percentage readout can jump around or show full charge when the cell is not at capacity. The firmware corrects this by running one complete charge-to-discharge cycle. Until that cycle completes, treat the percentage display as approximate and keep the USB cable handy for the first few sessions.
E-reader not powering on after battery replacement
Li-Polymer cells ship at storage voltage — typically around 3.6–3.8V — which can sit below the minimum boot threshold the Pocketbook BMS requires to initialise the e-ink controller. If the device shows nothing when you press the power button after the swap, connect it to a USB charger and leave it for 10 minutes before attempting to power on again. Once the cell climbs above the boot threshold, the device will start normally. Do not hold the power button repeatedly — wait for the charge indicator to appear on screen first.