Magellan Cyclo 500 HC Replacement Battery 3.7V 1100mAh

Magellan Cyclo 500 HC / 505 HC — 3.7V Li-ion Replacement Battery (BP-DG500-11/1500 MX)

This 3.7V, 1100mAh Li-ion cell replaces the internal battery in the Magellan Cyclo 500 HC and Cyclo 505 HC dash cameras. These compact units record continuously while driving and rely on this internal cell to buffer footage writes and sustain parking mode. When the original cell degrades, recording gaps and parking mode failures follow.

• Cyclo 500 HC and 505 HC compatibility: Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — the same cell services both. The BP-400H-11/1200 MX cross-reference covers the 505 HC variant specifically.
• Bench tested on actual hardware: We cycled this cell through charge and full-draw discharge on the Cyclo platform. The BMS accepted the cell without fault flags, voltage held steady through sustained recording load, and the protection circuit tripped correctly at low-voltage cutoff.
• Parking mode calibration after install: After fitting a new cell, complete one full drive cycle — hardwired power on, full charge, then engine off — before relying on parking mode. The dashcam's internal capacitor management needs one reference cycle against the new cell to set accurate parking mode duration thresholds.

Why the Cyclo 500 HC drops into standby instead of parking mode after engine off

Parking mode on these units draws continuously from the internal cell once 12V hardwire power cuts. If the cell voltage sags below the BMS threshold within seconds of engine off, the camera treats it as a low-battery shutdown rather than a parking mode entry. A degraded or discharged original cell is the most common cause. Replace the cell and complete a full charge cycle before testing parking mode again — the camera needs to see the cell sustain above 3.5V under load to commit to parking mode recording.

Footage file corruption on the Cyclo 505 HC after a parking session

Corrupted or missing clips after parking mode almost always trace back to a power interruption mid-write. When the internal battery voltage sags during an active file write, the camera cuts out before the file header closes — the clip exists on the card but won't play. A fresh cell with stable output voltage prevents mid-write sag. After replacing the battery, check that the dashcam fully powers down cleanly at end of session rather than cutting abruptly — clean shutdown means the BMS is holding voltage through the write buffer cycle.