Iribarri iK3 Crane Remote Replacement Battery 4.8V 2000mAh

Iribarri iK3 / iK4 — 4.8V Ni-MH Replacement Battery (BT27iK)

This is a 4.8V, 2000mAh Ni-MH replacement battery for the Iribarri iK3 and iK4 crane remote controls. It replaces OEM part numbers BT27iK and BT27iK-1. When the original cell degrades, crane remote response becomes erratic or the unit stops powering on entirely — this battery restores normal operation.

• iK3 and iK4 compatibility: Both models run on the same 4.8V NiMH pack with identical connector pinout and cell count. The BMS handshake on both units expects the same charge termination behaviour — delta-V cutoff at full charge — so the same cell works across both remotes without modification.
• Bench tested on actual hardware: We cycled this pack through crane remote charge and discharge sequences. The BMS responded correctly to delta-V cutoff on charge, and the pack held voltage under simulated solenoid activation loads without triggering a dropout.
• Monthly charge during crane downtime: Ni-MH cells self-discharge at roughly 1–3% per day at room temperature. On job sites where cranes sit idle for weeks, the pack can drop low enough to prevent a clean power-on. Charge the remote once a month during any idle period longer than two weeks.

Solenoid activation causing power dropout on a freshly installed battery

When a crane remote triggers a solenoid or relay, it draws a sharp inrush current in milliseconds. A Ni-MH cell at partial charge has higher internal resistance, so voltage sags hard under that spike. If the sag drops below the remote's minimum operating voltage, the unit resets or cuts out mid-command. This is not a faulty battery — it is a charge-state issue. Charge the pack fully before putting the remote into service; a full cell has lower internal resistance and handles the inrush without a dropout.

Remote showing low-battery indicator immediately after new cell install

A new or replacement Ni-MH pack ships at storage voltage — typically around 4.2–4.4V for a 4.8V four-cell pack. That is below the remote's full-charge threshold, so the low-battery indicator trips as soon as the unit powers on. This is normal and does not mean the battery is defective. Connect the remote to its charger and run a full charge cycle before use; resting voltage should read 5.0–5.2V at termination.