About this replacement
JAY Remote Control ECU — 3.6V Ni-MH Replacement Battery (UWB)
This is a 3.6V, 700mAh Ni-MH replacement battery for the JAY Remote Control ECU (Part No. UWB). It fits the Remote Control ECU, Remote Industrial HF Standard, and A001 crane remote transmitters. The battery powers the wireless transmitter that operators use to control industrial crane movements from a safe distance.
- ECU, HF Standard, and A001 compatibility: These three remote variants share the same 3.6V Ni-MH cell format, connector pinout, and BMS handshake protocol. Swapping the battery across this group does not require firmware changes or cell conditioning beyond a standard charge cycle.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the ECU platform. The BMS accepted the cell without error flags, and the transmitter held a stable voltage rail through repeated relay activation events.
- Monthly charge during idle periods: Crane remotes often sit unused for weeks between jobs. Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. If the remote is shelved for more than three weeks, put it on charge before the next job — a deeply discharged cell may not recover to full capacity after prolonged neglect.
Why the ECU remote cuts out the moment you activate a crane solenoid
Solenoid and relay activation pulls a short, sharp inrush current that can spike 3–5 times the steady-state draw. A weakened or partially discharged Ni-MH cell sees its terminal voltage drop sharply under that load. If the voltage dips below the BMS cutoff threshold — typically around 3.0V for a 3.6V pack — the BMS trips and the remote loses power mid-command. A fully charged, healthy cell handles the inrush without tripping. If dropout continues on a new, fully charged battery, check the solenoid driver circuit for a failing snubber diode that may be reflecting voltage back into the supply rail.
New battery installed but the remote shows low battery immediately
Ni-MH cells ship at storage voltage — typically 3.4–3.5V rather than a full 3.6V. The ECU remote reads terminal voltage to determine charge state, so a cell at storage voltage triggers the low battery indicator straight away. This is not a fault with the cell. Connect the remote to its charger and run a full charge cycle before use. Once the cell reaches 3.6V under the charger's termination logic, the indicator clears and the remote operates normally.