Trilithic TR-3 Replacement Battery 3.6V 2500mAh Ni-MH

Trilithic TR-3 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 2500mAh Ni-MH replacement battery for the Trilithic TR-3 handheld barcode scanner. It fits both the TR-3 and TR3 designations — same unit, different labelling across documentation. Capacity figure comes from the product specification, not a third-party estimate.

• TR-3 and TR3 compatibility: Both model references use the same 3.6V single-cell Ni-MH pack with identical connector orientation and form factor. The BMS on the TR-3 cradle expects a Ni-MH charge curve — this pack delivers exactly that, no handshake mismatch.
• Bench tested on actual hardware: We cycled this pack through repeated scan-trigger bursts and cradle charge sequences. The BMS accepted the charge curve without flagging a fault, and voltage held steady across rapid-fire scan events that typically stress a depleted cell.
• First-shift preparation for pick-and-pack: Place the scanner in its cradle for a full charge cycle before using it on the floor. Scan-trigger inrush current peaks when the cell is near minimum, and a pre-charged pack prevents false BMS trips during a heavy first shift.

Cradle showing a charging error on a new pack

The TR-3 cradle monitors contact resistance as part of its charge initiation check. If the dock contacts on either the cradle or the battery pack carry oxidation or debris, resistance reads high and the cradle flags a fault rather than starting the charge cycle. This is not a battery defect — it is a contact issue. Wipe the gold contacts on the pack and the cradle pins with a dry cloth, reseat firmly, and the charging indicator should return to normal within 30 seconds.

Scanner losing wireless connection during rapid scan bursts

During a fast scan sequence, the TR-3 draws current simultaneously from the scan trigger and the wireless radio polling the access point. On a weakened or partially charged cell, this combined inrush pulls the terminal voltage below the radio module's minimum operating threshold, causing the wireless link to drop. The scanner may still appear functional — the trigger fires — but decoded data stops transmitting. Charge the pack to full before a shift where scan burst frequency will be high, and check that terminal voltage at rest reads at least 3.4V before use.