Winait DC-T140B Compatible Battery 3.7V 720mAh Li-ion

Winait DC-T140B — 3.7V Li-ion Replacement Battery

This is a 3.7V, 720mAh (2.66Wh) lithium-ion battery for the Winait DC-T140B digital camera. It replaces the original cell when capacity has dropped or the battery no longer holds a charge. Dimensions are 39.50 x 35.40 x 5.60mm — verify these against your existing cell before ordering.

• DC-T140B compatibility: The DC-T140B uses a slim, low-profile cell to fit its compact body. The voltage rail sits at 3.7V nominal, which this cell matches. Any deviation in thickness or footprint will prevent the compartment door from closing correctly.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The BMS accepted the cell without triggering a protection cutoff, and the camera body recognised the battery after one full charge cycle completed in-camera.
• First-use charge cycle in the camera body: Charge this battery via the camera body or the OEM charger before your first shoot. Some compact camera BMS systems only calibrate the battery-remaining indicator after completing a charge cycle from within the body itself — skipping this step can cause the display to read inaccurately from the start.

Battery percentage jumping erratically on the DC-T140B display

The DC-T140B maps its battery indicator to a voltage-threshold curve calibrated for the original cell's discharge profile. A new replacement cell may have a slightly different discharge curve, causing the indicator to jump — for example, dropping from 80% to 40% in a few shots before stabilising. This is a calibration mismatch, not a fault with the cell itself. Run two to three full charge-discharge cycles and the indicator will track more accurately as the camera's BMS adjusts to the new cell's curve. After cycling, the resting voltage on a full charge should read approximately 4.1–4.2V at the contacts.

Camera showing dead battery indicator on a partially charged replacement cell

If the DC-T140B displays a dead or critically low battery indicator immediately after inserting this cell, the camera's BMS is reading a resting voltage below its acceptance threshold. This can happen when a new cell ships in a partially discharged state — typically below 3.5V — and the camera interprets that as a depleted or faulty battery. Remove the cell, place it in a compatible external charger until it reaches at least 3.7V resting voltage, then reinsert it. The camera should then power on normally and accept a subsequent in-body charge cycle.