About this replacement
Symbol LS4070 Series — 6V Ni-MH Replacement Battery (21-19022-01)
This is a 6V 750mAh Ni-MH battery for the Symbol LS4070, LS4071, LS4074, and LS7075 handheld barcode scanners. It replaces OEM part numbers 21-19022-01 and H4071-M. The cell fits the original battery compartment and works with the scanner's existing cradle charging circuit.
- LS4070 series fit: The LS4070, LS4071, LS4074, and LS7075 share the same 6V battery bay, connector pinout, and BMS handshake. All four models draw from the same voltage rail, so one pack covers the full group without modification.
- Bench tested on actual hardware: We cycled this pack through repeated scan-trigger events on the LS4070. The BMS held voltage within spec across burst scanning and registered a clean charge accept signal on the cradle dock each time.
- First-shift cradle charge: After installing, seat the scanner in its cradle for a full charge cycle before use in pick-and-pack. Scan trigger inrush current peaks when the cell is near minimum charge. A pre-charged pack prevents false BMS trips at the start of the first shift.
Cradle showing charging error on a new pack
A charging error on the cradle dock after fitting a new Ni-MH pack is almost always a contact resistance issue, not a battery fault. Dock contacts on the LS4070 cradle accumulate dust and oxidation, which raises resistance enough to trigger a charge fault. Wipe the gold contacts on both the battery and the cradle with a dry cloth, then reseat the scanner firmly. If the error clears, the pack is fine — the dock contacts were the cause.
Scanner not reading barcodes after a battery swap
If the scanner powers on but the laser fires weakly or fails to register a scan after fitting a new pack, the cell voltage is likely still below the minimum needed to drive the laser module at full power. The LS4070 laser assembly draws a short inrush current at trigger press, and a partially discharged Ni-MH cell can sag below 5.4V under that load. Place the scanner in the cradle until the charge indicator shows full, then test the read range. A fully charged pack should restore read distance to spec.