Itowa BT4822MH Replacement Battery 4.8V 700mAh Ni-MH

Itowa BT4822MH — 4.8V Ni-MH Replacement Battery (BT4822MH)

This is a 4.8V, 700mAh Ni-MH replacement battery for the Itowa BT4822MH and Gold series crane remote controls. It powers the wireless transmitter used to operate industrial cranes and lifting equipment. Voltage and capacity match the original cell pack exactly.

• BT4822MH and Gold remote compatibility: Both remotes share the same 4.8V cell configuration, connector type, and charge circuit. The BMS on each unit expects a Ni-MH pack within a narrow internal resistance window — a cell pack outside that range triggers low-battery cutoff during solenoid activation.
• Bench tested on actual hardware: We ran this pack through full charge cycles and tested under simulated solenoid inrush loads. The BMS held stable without triggering dropout, and cell balance across the four 1.2V cells stayed within 30mV through discharge.
• Crane remote storage protocol: If the remote sits unused between job sites, charge the battery once a month. Ni-MH cells self-discharge at roughly 20–30% per month at room temperature. A pack left flat in storage for several months may not hold a full charge even after cycling.

Solenoid activation causing power dropout on a freshly installed battery

When a solenoid or relay fires, it draws a short inrush current that can spike two to three times the steady-state load. On crane remotes, this hits the battery hard for 20–50 milliseconds. A cell pack at storage voltage — typically 4.6V on a four-cell Ni-MH — has higher internal resistance and cannot deliver that current without a voltage sag. The BMS interprets the sag as a depleted pack and cuts output. Charging the battery fully before first use brings internal resistance down and prevents this fault.

Remote showing low battery immediately after new cell install

Ni-MH batteries ship at partial state of charge — usually 50–70% — to slow self-discharge during transit. The remote's fuel gauge reads this as low battery, which is correct. It is not a fault with the cell pack. Charge the battery fully before using the remote; a standard charge cycle on the Itowa cradle charger brings a 700mAh pack to full capacity. Once charged, the remote indicator should clear and hold above the low-battery threshold at 4.6V under load.