Magellan Cyclo100 GPS Replacement Battery 3.7V 700mAh

Magellan Cyclo 100 — 3.7V Li-ion Replacement Battery (UF553436G)

This is a 3.7V Li-ion cell rated at 700mAh (2.59Wh), sized for the Magellan Cyclo 100 cycling GPS navigator. It fits both the Cyclo100 and Cyclo 100 variants. The cell matches the original OEM part UF553436G and ER-009311 references.

• Cyclo 100 platform fit: The Cyclo100 series uses a single compact Li-ion cell on a 3.7V rail. The connector pinout and BMS handshake on this replacement match the original, so the device powers on and reports charge state correctly without tripping a fault code.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Cyclo 100 platform. The BMS accepted the cell without rejection, charge termination triggered correctly at 4.2V, and the device reported accurate charge-level increments across the full discharge curve.
• Cold-start satellite acquisition after swap: After fitting this cell, power the unit on outdoors and let it run a full cold-start satellite acquisition before riding. GPS units store ephemeris data in volatile memory — a full power removal clears it, so the first fix after a battery swap takes longer than a normal warm start.

Saved routes and POIs missing after battery swap on the Cyclo 100

The Cyclo 100 stores some navigation data in battery-backed RAM. When the original cell is removed and voltage drops to zero, that memory loses power and the data it held can be wiped. Routes and points of interest saved to internal storage — not synced to a computer — are most at risk. Before swapping the battery, sync your ride data and routes to Magellan's desktop software or export files to a connected PC to avoid loss.

Cyclo 100 shutting off without warning at what looks like partial charge

This happens when the device's charge indicator is no longer calibrated to the actual discharge curve of the cell. The on-screen battery gauge still shows one or two bars, but the cell voltage has already crossed the low-voltage cutoff threshold — typically around 3.0V for this chemistry — and the BMS shuts the unit down to protect the cell. After fitting the new battery, run it through two full charge and discharge cycles on the device. This lets the firmware re-map the gauge to the new cell's actual voltage curve and restores accurate low-battery warnings.