Zebra WT41N0 Barcode Scanner Replacement Battery 3.7V 4400mAh

Zebra WT41N0 / WT4090 — 3.7V Li-ion Replacement Battery

This 3.7V 4400mAh Li-ion battery replaces the original pack in the Zebra WT41N0, WT4000, and WT4090 wearable mobile computers. These are wrist-mounted barcode scanning terminals used in warehouse picking, retail fulfilment, and logistics operations. Capacity figures come from the product data — 16.28Wh at 3.7V nominal.

• WT41N0 / WT4000 / WT4090 platform fit: All three models run the same 3.7V battery bay with identical connector orientation and BMS communication protocol. The pack dimensions — 113.13 x 43.88 x 27.22mm — match the wrist unit battery compartment without modification.
• Bench tested on actual hardware: We cycled this pack through repeated scan-trigger and wireless polling loads. The BMS held voltage above cutoff through sustained burst scanning and maintained stable draw during simultaneous radio and imager activation.
• First-shift preparation on the WT41N0: After installing, seat the scanner in its charging cradle for a full charge cycle before use on the floor. Scan-trigger inrush current is highest when the cell is near its minimum charge level — starting a pick shift on a partially charged new pack increases the chance of a BMS trip on the first heavy scan burst.

Cradle showing a charging error on a new pack

The WT41N0 cradle uses spring-loaded dock contacts that read BMS authentication before starting the charge cycle. A new pack straight from packaging sometimes has residual protective film or light oxidation on the gold contacts. If the cradle LED flashes an error immediately after seating, remove the pack, wipe the battery contacts with a dry lint-free cloth, and reseat firmly. The cradle should begin its charge handshake within 10 seconds of correct contact.

Scanner losing wireless connection during rapid scan bursts

The WT41N0 runs its 802.11 radio and barcode imager from the same cell simultaneously. During a rapid scan sequence, combined inrush from the imager trigger and radio transmission spikes draw sharply — if the pack voltage sags below the BMS hold threshold, the radio link drops before the scan engine does. This appears as a disconnection mid-shift rather than a flat battery. Keeping the cell above 3.5V through regular cradle top-ups between shifts prevents the sag event that triggers the drop.