About this replacement
Symbol MC35 / MC3504 / MC3574 — 3.7V Li-ion Replacement Battery (BTRY-MC35EABOE)
This is a 3.7V, 1400mAh Li-ion battery for the Symbol MC35 series handheld mobile computer. It fits the MC35, MC3504, MC3574, and MC35-C-E5B2 configurations. The cell slots into the same bay as the original pack and uses the same BMS communication protocol the MC35 expects on startup.
- MC35 series compatibility: The MC35, MC3504, MC3574, and MC35-C-E5B2 all share the same 3.7V battery bay, connector pinout, and BMS handshake. One pack covers all four variants without modification.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the MC35 platform. The BMS passed the device's authentication handshake on first contact and held the 3.7V nominal rail under combined scan-trigger and wireless polling load without tripping the protection circuit.
- First-shift preparation on the MC35: After installing, seat the scanner in its cradle and run a full charge cycle before your first pick-and-pack shift. The scan trigger draws the highest inrush current when the cell is near minimum charge — a pre-charged pack prevents false BMS trips the moment a worker starts scanning.
Cradle showing a charging error on a new MC35 battery pack
The MC35 cradle monitors contact resistance on the charge pins. If the dock throws an error immediately after seating a new pack, the problem is almost always the contact pads, not the battery. Oxidation or residue on the battery's gold contacts breaks the low-resistance path the cradle needs to begin a charge cycle. Wipe the pack contacts and cradle pins with a dry lint-free cloth, reseat firmly, and confirm the charging LED changes state within 10 seconds.
Scanner losing wireless connection during rapid scan bursts
During a fast-scan sequence, the MC35 fires the imager and polls the wireless radio nearly simultaneously. That combined inrush can pull the cell voltage low enough to trigger the BMS under-voltage threshold momentarily, dropping the radio connection. This is more common when the battery is below 20% charge. If the drop-outs track with scan frequency rather than distance from the access point, charge the pack to at least 50% before the next shift and the symptom will clear.