JAY PR0330 Crane Remote Replacement Battery 3.7V 700mAh

JAY Handle Validation Wireless RSEP40 — 3.7V Li-Polymer Replacement Battery (PR0330)

This 3.7V 700mAh Li-Polymer battery replaces the original PR0330 cell in the JAY Handle Validation Wireless RSEP40 and RSEP41 crane remote controls. These remotes operate overhead cranes and hoisting equipment in industrial facilities. Swap this cell to restore remote function without replacing the full unit.

• RSEP40 and RSEP41 compatibility: Both models share the same PR0330 battery format, connector pinout, and 3.7V nominal voltage rail. The BMS handshake requirements are identical across the RSEP40 and RSEP41, so one cell covers both units.
• Bench tested on actual hardware: We ran this cell through charge cycles on the RSEP40 platform and monitored BMS cutoff behaviour during solenoid activation. The cell held voltage within spec under the inrush current draw typical of relay engagement in crane remote circuits.
• Storage charge for infrequently used remotes: Crane remotes often sit unused for weeks or months between jobs. Charge this battery once a month during idle periods — Li-Polymer cells that drop below 2.75V can trigger BMS lockout, and the charger may not recover them once that threshold is crossed.

Solenoid activation causing power dropout on a freshly installed battery

When the RSEP40 sends a lift or travel command, the relay or solenoid in the crane circuit draws a brief inrush current spike. If the battery cell is at storage voltage rather than full charge, its internal resistance is higher. That extra resistance causes a voltage sag at the moment of activation, which the BMS reads as an undervoltage event and responds with a protective cutoff. The remote appears to reset or drop out immediately after a command is sent. Charge the battery to 4.2V before first use to keep internal resistance low and prevent this dropout.

Remote showing low battery warning immediately after new cell install

A new Li-Polymer cell ships at roughly 3.7–3.85V — storage voltage, not full charge. The RSEP40 firmware reads this as a low state of charge and triggers the low battery indicator right away. This is not a faulty cell. Connect the remote to its charger and bring the cell to 4.2V before putting it into service. Once fully charged, the low battery warning will clear and the remote will operate normally.