Psion HU3000 Teklogix 7535 Barcode Scanner Replacement Battery 7.4V

Psion Teklogix 7535 / 7530 G2 — 7.4V Li-ion Replacement Battery (HU3000)

This is a 7.4V, 2500mAh Li-ion replacement for the Psion Teklogix 7535, 7535LX, and 7530 G2 rugged mobile computers. These handheld devices are used in warehouse picking, retail stockrooms, and field service for barcode scanning and data collection. Swapping a degraded original pack with this unit restores the voltage rail the device needs to run scans and wireless sessions through a full shift.

• Teklogix 7535, 7535LX, and 7530 G2 compatibility: All three models share the same battery bay geometry, contact pinout, and 7.4V nominal voltage rail. The OEM part numbers HU3000 and 1030070-003 cross-reference across the full platform, so one pack covers the entire family without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a 7535 unit, monitoring BMS handshake at power-on and cell balance across both cells. The protection circuit held cutoff at the correct undervoltage threshold and did not trip spuriously during simulated scan-trigger inrush events.
• First-shift preparation for pick-and-pack use: After installing the pack, place the 7535 in its cradle and run a full charge cycle before starting any scan work. The scan trigger draws its highest inrush current when the cell is near minimum voltage — a fully charged cell on the first shift prevents false BMS trips that can look like a faulty battery.

Cradle showing a charging error on a new pack

The Teklogix charging cradle communicates with the battery's BMS via the contact strip on the base of the unit. If the cradle throws a charge fault immediately after a new pack is seated, the most common cause is contact resistance — not a failed cell. Oxidation or debris on either the pack contacts or the cradle pins raises resistance above the threshold the dock uses to verify a valid battery. Wipe the gold contacts on the pack and the cradle pins with a dry lint-free cloth, reseat the pack firmly, and confirm the charge indicator lights within 30 seconds.

Scanner losing wireless connection during rapid scan bursts

On the 7535, the wireless radio and the scan engine fire simultaneously during fast back-to-back scans — both pulling current at the same moment. If the battery's internal resistance has climbed (common in aged cells), the combined inrush causes a voltage sag that drops the radio below its minimum operating threshold, killing the session. A fresh pack with low internal resistance holds the voltage rail stable through that combined draw. If dropouts continue after fitting this replacement, check that the device firmware is current — older builds have a known aggressive radio power-save setting that compounds the issue.