About this replacement
Symbol LS4278 / DS6878 Series — 3.6V Ni-MH Replacement Battery (BTRY-LS42RAAOE-01)
This is a 3.6V 700mAh Ni-MH rechargeable battery for the Symbol LS4278 and DS6878 series handheld barcode scanners. It replaces OEM part numbers BTRY-LS42RAAOE-01 and 82-67705-01. The pack fits the LS4278, LS4278-M, DS6878, and DS6878-SR, along with three additional variants in the same family.
- LS4278 and DS6878 family fit: These models share the same battery bay geometry, contact pin layout, and BMS handshake protocol. The 3.6V rail is consistent across the cordless laser and imager variants in this family, so one pack covers the full range listed above.
- Bench tested on actual hardware: We ran this pack in an LS4278 cradle and confirmed the BMS accepted the charge cycle without error flags. The protection circuit responded correctly to both charge cutoff and over-discharge conditions during load testing.
- First-shift preparation on pick-and-pack lines: After installing a new pack, seat the scanner in its cradle and complete a full charge cycle before use. The scan trigger draws its highest inrush current when the cell is near minimum charge — a fully conditioned pack prevents false BMS trips at the start of a shift when scan volume is highest.
Cradle showing charging error on a new pack
Ni-MH cells shipped in storage state can present a voltage low enough that some cradles interpret the pack as faulty rather than discharged. The cradle's charge controller reads the initial cell voltage and may throw an error before attempting recovery charging. Pull the scanner from the cradle, wipe the gold contact pads on both the battery and the cradle dock with a dry cloth, then reseat firmly. If the error clears, allow the full charge cycle to complete before pulling the scanner for use.
Scanner losing wireless connection during rapid scan bursts
The LS4278 runs its radio and laser decode engine from the same 3.6V cell simultaneously. During a fast scan burst, the combined inrush from the laser firing and the Bluetooth polling interval causes a momentary voltage sag on a degraded or partially charged cell. The BMS interprets this sag as an under-voltage event and briefly throttles output, dropping the wireless link mid-burst. Charge the pack fully — confirmed charge means resting voltage at 4.2V equivalent post-charge rest — before beginning a high-frequency scanning session.