Dolphin 99EX Replacement Battery 3.7V 5200mAh Li-ion

Dolphin 99EX Series — 3.7V Li-ion Replacement Battery (99EX-BTEC-1)

This is a 3.7V, 5200mAh Li-ion replacement battery for the Dolphin 99EX, 99EXhc, and 99GX rugged handheld scanners. It matches the OEM voltage rail and physical form factor of the original pack. The 99EX-BTEC-1 and 99EX-BTES-1 part numbers both cross to this cell.

• 99EX, 99EXhc, and 99GX compatibility: These models share the same battery bay dimensions, 3.7V logic rail, and BMS handshake protocol — one cell fits all three without any adapter or firmware change.
• Bench tested on actual hardware: We ran this pack through a full charge-discharge cycle on the 99EX platform. The BMS communicated correctly with the scanner's charge controller, and the protection circuit responded to simulated over-draw conditions without latching off.
• First-shift charging on the Dolphin cradle: After installing, place the 99EX in its charging cradle and run a full cycle before starting work. The scan trigger and wireless radio together draw a sharp inrush current when the cell is near minimum — a fully charged cell prevents the BMS from tripping on that first scan burst of the shift.

Cradle showing charging error on a new pack

A new pack sitting at storage charge — typically around 3.6V — can trigger a charging fault on the 99EX dock if the contact resistance is high. The cradle interprets the low initial current as a failed cell rather than a fresh one. Wipe the gold contacts on both the battery and the dock with a dry cloth, then reseat the scanner firmly. If the fault clears, the issue was contact resistance, not the cell.

Scanner losing wireless connection during rapid scan bursts

The 99EX runs its wireless radio and imager from the same cell simultaneously. During a rapid scan burst, the combined draw can cause a voltage sag that drops the radio below its minimum operating threshold — the connection drops even though the scanner itself stays on. This is more common with a degraded original pack but can also occur if a replacement cell is installed without a prior full charge. Charge the battery to 100% before a high-throughput shift and the voltage sag stays within the radio module's tolerance range.