About this replacement
iRobot Braava Jet 240 Series — 3.6V Li-ion Replacement Battery (4446040)
This is a 3.6V 2000mAh Li-ion battery for the iRobot Braava Jet 240, 241, 244, and 245 robotic floor mopping units. It slots into the rear battery compartment and powers the motor, navigation, and pad-vibration systems. Capacity is sourced from product data at 7.2Wh.
- Braava Jet 240 series compatibility: The 240, 241, 244, and 245 share the same 3.6V battery bay, connector pinout, and BMS handshake protocol. Swapping between these models is straightforward — the cell geometry and communication lines are identical across the series.
- Bench tested on actual hardware: We ran this cell through the Braava Jet 240's charge cycle and confirmed the BMS accepted the handshake without fault codes. The charging circuit held a steady current draw and the battery reached full charge without thermal events or cutoff interruptions.
- Wet-mopping pad cycle care: The Braava Jet 240 runs wet pad cycles that stress the motor more than dry sweeping passes. If the robot is stored with a wet pad attached after a cycle, residual moisture near the battery contacts can accelerate corrosion — always remove and dry the pad before storing the unit.
Capacity fade on the Braava Jet 240 after shallow charge cycles
The Braava Jet 240 is a low-draw device, and many users charge it after every short mopping pass rather than running it to depletion. Li-ion cells in low-draw devices degrade faster from repeated shallow cycles than from full charge-discharge cycles. Over time, the BMS recalibrates its state-of-charge window downward, and the robot shuts off earlier than expected even on a freshly charged cell. If the original battery was charged daily after brief sessions, the replacement cell will restore full capacity — but the same shallow-cycle habit will degrade it at the same rate.
Braava Jet 240 not responding after battery replacement — no movement, no indicator lights
This happens when the BMS in the new cell has not been initialised by the charger. The Braava Jet 240's firmware expects a specific voltage handshake before it will power the motor or light the status LEDs. Seat the battery, connect the dock charger, and leave it for at least 60 seconds before pressing the clean button — this gives the BMS time to complete its initial communication with the charger circuit. If the indicator still does not light, confirm the dock contacts are clean and the supply voltage at the dock output reads 5V.