About this replacement
Cavotec M9-1051-3600 EX / MC-3000 — 7.4V Li-ion Replacement Battery (M5-1051-3600)
This 7.4V 3400mAh Li-ion battery replaces the original pack in the Cavotec M9-1051-3600 EX, MC-3, and MC-3000 wireless crane remote controls. These remotes are used to operate overhead cranes and hoisting equipment in warehouses, ports, and heavy manufacturing facilities. Same voltage, same OEM part reference — no modifications needed at the remote.
- MC-3 and MC-3000 platform compatibility: The MC-3 and MC-3000 share the same battery bay geometry and 7.4V two-cell architecture as the M9-1051-3600 EX. All three models use the same BMS handshake protocol, so this pack communicates charge state to the remote's firmware without modification.
- Bench tested on actual hardware: We ran this battery under simulated solenoid activation cycles — the inrush current events that trip weaker packs. The BMS held voltage above the dropout threshold across repeated relay-switching loads without triggering a protection cutoff.
- Monthly charge cycle for idle remotes: Crane remotes often sit unused for weeks between operational periods. Charge this battery once a month during idle periods — Li-ion cells discharged below 2.5V per cell trigger BMS lockout, and the pack may not respond to a charger even when reconnected.
Solenoid activation causing power dropout on a new battery
When a crane remote activates a solenoid or relay, the inrush current spike can momentarily pull cell voltage below the BMS protection threshold. If that threshold is crossed, the BMS trips and the remote cuts out — even with a freshly installed battery. This is not a faulty battery; it is a BMS response to current demand exceeding the rated discharge limit. Ensure the replacement pack matches or exceeds the original capacity rating, and confirm the battery is fully charged before use — a partially charged cell has higher internal resistance and sags harder under load.
Remote showing low battery immediately after a new pack is installed
Replacement Li-ion packs ship at storage voltage — typically around 3.6V to 3.7V per cell, not full charge. The Cavotec remote reads cell voltage to calculate state of charge, so a pack at storage voltage registers as partially depleted the moment it is installed. This is expected behaviour, not a defective battery. Place the pack on charge before the first use and run it to full voltage — 4.2V per cell, or 8.4V total — before operating the crane.