AEE SD18 Compatible Battery 3.7V 900mAh DS-SD20

AEE SD18 / SD20 Series — 3.7V Li-Polymer Replacement Battery (DS-SD20)

This 3.7V, 900mAh lithium-polymer cell replaces the DS-SD20 battery in AEE action cameras. It fits the SD18, SD19, SD20, and SD21 along with compatible models in that series. Dimensions are 37.84 × 31.71 × 11.36mm — confirm these against your existing cell before installing.

• SD18 / SD19 / SD20 / SD21 platform fit: These four models share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. One cell format covers the full group without adapter or wiring changes.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an SD-series body. The BMS accepted the cell, voltage hold was stable across the mid-range, and cutoff triggered cleanly at the low-voltage threshold without locking the camera body.
• First-install charge cycle on AEE bodies: Charge the new cell fully inside the camera body using the OEM cable before your first shoot. AEE's battery-remaining display calibrates its threshold map during that initial in-body charge cycle — skipping it causes the indicator to read incorrectly from the first session onward.

Why the SD18 shows a dead-battery icon on a partially charged replacement cell

AEE action cameras map battery percentage against a voltage-discharge curve stored in firmware. A new lithium-polymer cell has a slightly flatter discharge curve in the mid-range than a worn original cell. The camera reads voltage, compares it to the stored curve, and can flag a false low-battery warning if the curves don't align on first use. Running one full charge cycle inside the camera body — not an external charger — lets the firmware re-anchor its voltage-to-percentage mapping to the new cell. After that cycle, the indicator reads accurately.

Battery percentage jumping erratically during recording

Sustained 1080p video recording pulls a continuous load from the sensor, processor, and write buffer simultaneously. Under that combined draw, voltage sags momentarily — the camera's indicator interprets each sag as a drop in charge level, then recovers when the load eases briefly. This produces jumpy or inconsistent percentage readings even when the cell is not depleted. If the jumping persists beyond the first charge cycle, check that the battery contacts on both cell and bay are clean and making full contact — oxidation on either surface increases resistance and amplifies voltage sag at the meter point.