About this replacement
Teleradio TG-TX-MNL — 3.7V Li-Polymer Replacement Battery (22.381.3)
This 3.7V 1500mAh Li-Polymer cell replaces OEM part 22.381.3 in the Teleradio TG-TX-MNL wireless crane remote transmitter. It slots into the transmitter housing at 51.60 × 34.80 × 8.10mm and matches the original connector and BMS handshake. Voltage and capacity are sourced from the OEM specification — 3.7V nominal, 5.55Wh total energy.
- TG-TX-MNL transmitter fit: The TG-TX-MNL uses a single-cell Li-Polymer pack at 3.7V nominal. That voltage rail drives the radio transmitter module and the solenoid-activation logic simultaneously. Any cell that drifts below the BMS cutoff threshold will drop the transmitter mid-operation, which is why cell capacity and BMS compatibility must both match the original exactly.
- Bench tested on actual hardware: We cycled this cell through transmitter power-on, solenoid relay activation, and sustained radio transmission. The BMS held stable through repeated inrush events and did not trip at full charge. Voltage recovery after a solenoid pulse measured within OEM tolerance.
- Monthly charge interval for idle remotes: Crane remotes often sit unused for weeks between jobs. Li-Polymer cells left uncharged below 2.5V enter a deep-discharge state the BMS may not recover from. Charge this battery once a month during any idle period to keep the cell voltage above the BMS re-engagement threshold.
Solenoid activation causing power dropout on a freshly installed battery
When a crane remote activates a solenoid or relay, the current draw spikes sharply for a few milliseconds. If the battery cell is at storage voltage — typically around 3.6V — internal resistance is higher than at full charge. That resistance amplifies the voltage sag during the inrush event. Some BMS circuits interpret that sag as an under-voltage fault and disconnect the cell entirely, cutting the transmitter mid-command. Charge the battery fully to 4.2V before first use to minimise internal resistance and keep the BMS from tripping on relay activation.
Remote showing low-battery indicator immediately after cell swap
A new Li-Polymer cell ships at storage voltage, usually 3.6–3.7V, not at full charge. The TG-TX-MNL transmitter reads cell voltage to calculate charge state, so a cell at 3.6V will register as partially depleted even though it is brand new. This is not a faulty cell — it is a cell that has not yet been charged. Connect the transmitter to its charger and run a full charge cycle until the indicator clears before putting the remote back into service.