Leaf AFi-II 7 Compatible Battery 7.4V 3000mAh Li-ion

Leaf AFi-II 7 / Aptus Series — 7.4V Li-ion Replacement Battery

This is a 7.4V, 3000mAh (22.2Wh) lithium-ion replacement battery for the Leaf AFi-II 7 and Aptus-series medium format digital camera backs. It fits the AFi-II 7, Aptus 22, Aptus 65, Aptus 75, and seven additional Aptus models that share the same battery format. No OEM part number is published by Leaf for this cell.

• AFi-II 7 and Aptus compatibility: These camera backs share a common battery bay dimension, voltage rail, and connector pinout. The 7.4V nominal cell voltage matches the power input spec across the Aptus line, so the same cell works across the range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on compatible Leaf hardware. The BMS engaged cleanly at both ends of the cycle — no mid-cycle cutoffs, no false full-charge flags during acceptance testing.
• First-install charge protocol for Aptus backs: Insert the new cell and charge it fully inside the camera body or via the OEM charger before your first shoot. Leaf's battery-remaining indicator maps to a voltage-discharge curve it learns during the first in-body charge cycle — skipping this step causes erratic percentage readings in the field.

Dead battery indicator on a partially charged replacement cell in the Aptus back

Leaf Aptus backs use a voltage-threshold system to estimate remaining charge. A new third-party cell ships at storage voltage — typically around 3.7–3.8V per cell — which can fall below the camera's low-battery threshold before the back has learned the cell's discharge curve. The back then flags a dead battery even though the cell has usable capacity. One full charge cycle through the OEM charger resets this. After that cycle the indicator tracks normally.

Battery percentage jumping or freezing mid-shoot on the Aptus display

This happens when the camera's fuel-gauge logic is mapping an unfamiliar discharge curve. The Aptus back stores voltage-to-percentage reference points from previous cycles, and a new cell with a slightly different discharge slope causes the indicator to skip or stall. It is a display calibration issue, not a cell fault. Run two full charge-discharge cycles through the camera body and the percentage tracking will stabilise — confirm the cell rests at 8.4V at full charge before calling the cell faulty.