Pentax D-LI109 K-R Compatible Battery 7.4V 900mAh

Pentax K-R / K-2 / K-S1 Series — 7.4V Li-ion Replacement Battery (D-LI109)

The D-LI109 is a 7.4V, 900mAh Li-ion battery that fits the Pentax K-R, K-2, K2, K-S1, and compatible K-series DSLR bodies. It powers the imaging sensor, autofocus motor, LCD panel, and onboard processing during shooting sessions. Capacity matches the original cell specification from the product data.

• K-series body compatibility: These Pentax bodies share the same battery bay dimensions, connector pinout, and BMS handshake protocol, which is why a single D-LI109 cell works across the K-R, K-2, and K-S1 platforms without modification.
• Bench tested on actual hardware: We cycled this cell through the K-R body and a Pentax OEM charger. The BMS accepted the cell on first contact, charge termination triggered correctly at full voltage, and the battery indicator reported status without error flags.
• First-cycle initialisation on K-series bodies: Run the first full charge from inside the camera body or an OEM Pentax charger — not a generic USB adapter. Some K-series bodies require one in-body charge cycle before the battery-remaining display maps correctly to the new cell's discharge curve.

Flash recycling slowing down mid-shoot on a new D-LI109 cell

The built-in flash on K-series bodies pulls a sharp current spike to recharge the capacitor between shots. At the tail end of a discharge cycle, cell voltage sags enough that capacitor recharge slows noticeably — this is normal behaviour tied to the discharge curve, not a faulty cell. If it happens early in a charge, check that the cell was fully charged before the session. A rested, fully charged D-LI109 should sustain consistent flash recycling through the majority of its charge.

Battery percentage jumping or reading incorrectly on the K-R display

The K-R maps its battery indicator to specific voltage thresholds calibrated to the original cell's discharge curve. A new third-party cell can discharge along a slightly different curve, causing the indicator to skip levels or show a sudden drop. This is a display calibration issue, not a capacity fault. Running one full charge-discharge cycle through the camera body allows the BMS to recalibrate — after that, readings stabilise. If the display still jumps after two full cycles, verify resting voltage with a multimeter; a healthy cell should read between 7.2V and 8.4V.