Lego Arduino Robot 3.7V 1700mAh Compatible Battery 14030

Lego Arduino Robot — 3.7V Li-Polymer Replacement Battery (14030)

This 3.7V 1700mAh Li-Polymer battery is a direct replacement for the Lego Arduino Robot (Part No 14030). It fits the programmable robotic platform and powers the onboard motors, sensors, and computer functions. Capacity is sourced from product data at 6.29Wh.

• Arduino Robot platform fit: The Arduino Robot uses a single-cell Li-Polymer pack at 3.7V nominal to power both the motor board and control board from one supply rail. This replacement matches that voltage and the 14030 form factor, so the connector and cell dimensions align with the original battery bay.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Arduino Robot platform. The BMS responded correctly to low-voltage cutoff and accepted a full charge without fault flags on the control board.
• Program storage before swap: Export all sketches and stored programs to your PC before removing the battery. The Arduino Robot holds active program data in RAM backed by the main battery — pulling the cell without exporting first wipes any programs not already saved to external storage.

Voltage sag under combined servo and motor load on the Arduino Robot

The Arduino Robot runs both drive motors and sensor servos from the same 3.7V cell. When all motors fire simultaneously — such as during a turning manoeuvre with active sensors — instantaneous current draw spikes and cell voltage sags briefly below the control board's stable operating threshold. A worn or partially discharged cell cannot hold voltage under this combined load, so motor commands execute at reduced power or timing shifts. This replacement cell's 1700mAh capacity at 3.7V nominal gives the BMS enough headroom to sustain the surge without triggering an undervoltage cutoff during normal movement routines.

Robot not connecting to the programming app after a battery swap

Replacing the battery performs a hard power cycle on the Arduino Robot's Bluetooth module, which clears its paired-device state. The app on your tablet or PC still shows the robot as paired from the previous session, but the robot itself has no matching record after the power loss. Delete the robot from your device's Bluetooth settings entirely, then put the robot into pairing mode by powering it on fresh. Re-pair from scratch and the connection restores cleanly.