About this replacement
JAY Transmitter ERUS / UR E — 3.7V Li-Polymer Replacement Battery (PR0248)
This is a 3.7V, 700mAh Li-Polymer battery for the JAY ERUS and UR E handheld crane transmitters. It replaces OEM part PR0248 directly. The transmitter powers wireless control of cranes and hoisting equipment, so a dead or degraded cell takes the entire lifting operation offline.
- ERUS and UR E transmitter fit: Both units share the same battery bay dimensions, connector pinout, and 3.7V supply rail. The BMS handshake is identical across both models, so a single cell covers either unit without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the transmitter platform. The BMS accepted the cell without fault codes, voltage held steady across simulated solenoid activation events, and cutoff thresholds triggered correctly at low-voltage limits.
- Infrequent-use charging schedule: Crane remotes often sit unused for weeks between jobs. Charge this battery at least once a month during idle periods. Li-Polymer cells discharged below 2.5V enter a deep-discharge state — the BMS locks out and the cell may not recover even when a charger is connected.
Solenoid activation causing power dropout on a freshly installed battery
When the transmitter triggers a crane solenoid or relay, the inrush current spike can momentarily exceed the BMS current threshold. This causes the BMS to trip and cut output, which looks like the remote switching off mid-command. A cell at partial charge has higher internal resistance and is more likely to sag under that load. Make sure the battery is fully charged before operating — a full cell handles inrush spikes with less voltage sag.
Remote shows low battery indicator immediately after fitting a new cell
Li-Polymer cells ship at storage voltage — typically around 3.7V to 3.85V — not at full charge. Some transmitter firmware interprets anything below the full-charge threshold as a low battery condition. This is not a faulty cell. Connect the battery to the charger before first use and bring it to 4.2V. The low-battery indicator will clear once the cell reaches the firmware's minimum threshold.