Midland XTC400 Replacement Battery 3.7V 1800mAh Li-ion

Midland XTC400 / XTC450 — 3.7V Li-ion Replacement Battery (BATT17L)

This is a 3.7V, 1800mAh Li-ion cell that replaces the OEM BATT17L battery in the Midland XTC400 and XTC450 action cameras. It slots into the same battery compartment as the original and draws through the same connector. Voltage and capacity match the stock specification exactly.

• XTC400 and XTC450 compatibility: Both models share the BATT17L form factor, connector pinout, and 3.7V supply rail. The camera's power management circuit draws from the same voltage threshold on either body, so one cell fits both without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the XTC400 body. The BMS accepted the cell without triggering a fault state, and the camera powered on and recorded normally across full discharge.
• First-use charge cycle on the XTC400: Charge this cell fully inside the camera body before your first outing. Some action camera BMS systems need one complete in-body charge cycle before the battery-remaining indicator maps correctly to the new cell's discharge curve.

XTC400 battery indicator reading full then dropping suddenly mid-recording

The XTC400 maps its battery percentage to a voltage threshold table calibrated against the original cell's discharge curve. A new third-party cell can discharge along a slightly different curve, causing the indicator to read high until the voltage crosses the first threshold, then jump down sharply. This is a calibration artefact in the camera's firmware, not a cell defect. Running two or three full charge-discharge cycles through the camera body lets the BMS build a more accurate picture of the new cell's behaviour.

XTC400 showing no battery or refusing to power on with a charged replacement cell

If the camera shows a dead-battery icon or fails to boot despite the cell being charged, the BMS authentication check has not yet accepted the replacement. This happens on first install when the cell voltage sits below the camera's minimum wake threshold — typically around 3.4V — after storage. Place the cell in the camera and connect the USB charger for at least 15 minutes, then attempt to power on. If the camera still refuses to start, charge to a measured 3.7V via an external Li-ion charger before reinserting.