Radio Shack 55026650 GPS Replacement Battery 3.7V 1350mAh

Radio Shack 55026650 — 3.7V Li-Polymer Replacement Battery

This 3.7V 1350mAh Li-Polymer cell replaces the original battery in the Radio Shack 55026650 portable GPS navigator. It matches the original voltage and physical footprint at 50.81 × 34.28 × 7.81 mm. Capacity is drawn directly from product data at 5Wh.

• Radio Shack 55026650 fit: This cell targets one model. The connector orientation and cell dimensions match the 55026650 battery bay. No voltage mismatch — the unit expects 3.7V nominal, and that's what this cell delivers.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Li-Polymer test rig. The BMS held cutoff at the correct low-voltage threshold and accepted charge without triggering protection lock. No thermal event at any stage.
• Cold-start satellite acquisition after swap: After fitting this cell, power the GPS fully on outdoors before your first use. A full power interruption triggers a cold start — the receiver has lost its last known position and almanac data from RAM. Expect 5–10 minutes for first satellite fix versus under a minute for subsequent warm starts.

GPS accuracy reduced as battery voltage drops below threshold

Some portable GPS units scale back receiver sensitivity when cell voltage falls toward the low cutoff point. The unit prioritises keeping the display and core processor alive over maintaining full RF gain in the GPS receiver. The result is fewer satellites tracked and reduced position accuracy — not a fault with the cell itself. Keeping the battery topped up before long routes avoids this entirely.

Device shuts off without warning before the low-battery indicator appears

This happens because the battery indicator is calibrated against the original cell's discharge curve. A new Li-Polymer cell may have a slightly different voltage-to-capacity curve, throwing off the percentage estimate. The GPS hits the hardware low-voltage cutoff — typically around 3.0V — before the software indicator reaches zero. Run one full discharge cycle from 100% to automatic shutoff, then charge to 100% uninterrupted to let the device recalibrate its voltage threshold.