Iribarri iK3 Crane Remote Replacement Battery 4.8V 2500mAh

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

This is a 4.8V, 2500mAh Ni-MH replacement battery for the Iribarri iK3 and iK4 wireless crane remote controls. It slots directly into the remote handset that operators use to run overhead cranes and hoisting equipment on industrial sites. OEM part numbers BT27iK and BT27iK-1 both cross to this cell pack.

• iK3 and iK4 compatibility: Both remotes share the same 4.8V cell configuration, connector pinout, and charge circuit. One battery pack covers both handsets without modification.
• Bench tested on actual hardware: We cycled this pack through repeated solenoid-activation sequences on the iK3. The BMS held voltage under inrush current loads without tripping. Cell balance across all four NiMH cells stayed within 0.05V at full charge.
• Monthly charge cycle for idle remotes: If the remote sits unused between jobs, put it on charge once a month. NiMH cells in a discharged state lose capacity permanently through voltage reversal when left flat for extended periods — a problem specific to multi-cell packs like this one.

Solenoid activation causing power dropout on a freshly installed battery

When a crane remote triggers a solenoid or relay, the inrush current spike can briefly sag the supply voltage below the remote's operating threshold. NiMH packs at storage charge — typically 3.8–4.0V for a 4.8V pack — have elevated internal resistance and sag harder than a fully charged cell. The remote reads this as a low-voltage fault and cuts out. Charge the pack to full before the first operation cycle; internal resistance drops significantly at 100% state of charge and the voltage sag during solenoid activation stays within the remote's tolerance.

Remote showing low battery indicator immediately after swapping the cell pack

A new NiMH pack ships at storage voltage, not full charge. The iK3 reads terminal voltage on startup to estimate state of charge, and a pack sitting at 4.0V or below will trigger the low-battery warning straight away. This is not a fault with the battery. Connect the handset to its charger for a full charge cycle before use. Once the pack reaches 4.8V terminal voltage, the low-battery indicator will clear on the next power-on.