Gryphon RBP-GM40 Compatible Battery 3.7V 3400mAh Li-ion

Gryphon GM4100 / RBP-GM40 — 3.7V Li-ion Replacement Battery (128000894)

This is a 3.7V, 3400mAh Li-ion battery replacing OEM part 128000894 in the Gryphon GM4100 and RBP-GM40 handheld barcode scanners. These scanners are used in retail, warehousing, and logistics environments where a dead battery stalls pick-and-pack or receiving operations. Cell dimensions are 68.70 × 18.40 × 18.40mm — same as the original pack.

• GM4100 and RBP-GM40 compatibility: Both models share the same 3.7V battery bay, connector pinout, and BMS handshake protocol. One pack covers both units without modification.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the GM4100 platform. The BMS reported correct state-of-charge, and the scan trigger and wireless radio drew current cleanly without tripping the protection circuit.
• First-shift preparation: After installing, place the scanner in its cradle for a full charge cycle before use. Scan trigger inrush current is highest when the cell is near minimum — a fully charged cell prevents false BMS trips during the first shift in a high-frequency scan environment.

Cradle showing a charging error on a new pack

Charging docks on the GM4100 communicate with the battery over a contact array on the base of the unit. If those contacts have oxidation or debris from warehouse use, the dock reads a high-resistance connection and flags a charge fault rather than starting a charge cycle. This is not a faulty battery. Wipe the gold contacts on both the battery and the dock with a dry cloth, reseat the scanner firmly, and the charge indicator should switch to active within 30 seconds.

Scanner dropping wireless connection during rapid scan bursts

The GM4100 runs its wireless radio and imager from the same cell simultaneously. During a fast scan burst, the combined current draw from the radio transmit pulse and the imager illumination can cause a brief voltage sag. If the cell voltage dips below approximately 3.2V under that load, the BMS may throttle output or momentarily drop the wireless session. A fully charged replacement cell at 3.7V nominal provides the headroom needed to sustain both loads. If drop-outs continue after a full charge, check that the wireless polling interval in your host software is not set to continuous — increasing it to 100ms reduces the concurrent draw spike.