Ecovacs CEN330 Compatible Battery 11.1V 2600mAh Li-ion

Ecovacs CEN330 / CR330 / CR333 — 11.1V Li-ion Replacement Battery (ICR18650 3S1P)

This is an 11.1V 2600mAh Li-ion replacement battery for the Ecovacs CEN330, CR330, and CR333 robotic vacuum cleaners. It uses an ICR18650 3S1P cell configuration — three 18650 cells in series — matching the voltage rail the original pack runs on. Fit the replacement when the robot starts returning to dock early, cutting out mid-cycle, or refusing to hold a full charge.

• CEN330, CR330, and CR333 compatibility: These three models share the same battery bay dimensions, connector pinout, and BMS communication protocol. The 11.1V nominal voltage and cell geometry are consistent across the series, so one replacement SKU covers all three without any modification.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on a CEN330 unit. The BMS responded correctly to the charger handshake, cell balancing activated between cycles, and overcurrent protection tripped as expected under a simulated motor-stall condition.
• Dock charging habit on the CEN330: Do not leave the robot sitting on the dock permanently between uses. Continuous trickle charging through the dock accelerates capacity fade on Li-ion cells. Charge the robot to full, then remove it from the dock until the next scheduled clean.

Suction dropping before the battery indicator reaches low on the CEN330

The CEN330 motor draws current proportional to suction load. A partially blocked filter or brush roll forces the motor to pull more amps than rated, which causes the pack voltage to sag under load even when the cell state-of-charge is still mid-range. The BMS reads that voltage sag and throttles output to protect the cells — so the robot slows or loses suction well before the indicator registers low. Clean the filter and check the brush roll for hair wrap first. If suction recovers after cleaning, the battery is not the problem. If sag continues on a clean filter, the pack cells have degraded and the replacement is the correct fix.

Motor cutting out mid-clean and then recovering after a few seconds

This is an overcurrent trip, not a flat battery. When the brush roll jams or the suction path is blocked, current draw spikes sharply. The BMS cuts the output circuit to prevent cell damage, which kills the motor. After a few seconds the BMS resets and power returns. If this happens repeatedly on a cleared brush roll and clean filter, the cells in the original pack can no longer sustain the current the motor demands at start-up — typically around 3A to 5A peak on the CEN330. Replace the pack and confirm the new battery holds above 10.5V under load during the first cleaning cycle.