About this replacement
Ecovacs Winbot W733 / W720 — 11.1V Li-ion Replacement Battery (10000254)
This 11.1V, 2600mAh Li-ion battery replaces OEM part 10000254 in the Ecovacs Winbot W733, TBW60, Winbot 733, and W720 robotic window cleaning units. The Winbot W733 is a wall-climbing window cleaner — not a floor vacuum — and this cell matches the voltage rail and connector the unit's BMS expects. Capacity figures come from the product data, not inflated web claims.
- W733, W720, and TBW60 compatibility: These models share the same 11.1V three-cell Li-ion architecture and the same OEM battery slot dimensions (69.50 × 55.30 × 19.40mm). The BMS handshake protocol is identical across the range, so one cell covers all listed variants without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a W733 unit. The BMS accepted the replacement without error flags, held voltage within spec across the full suction and navigation load cycle, and the safety cutoff triggered correctly at low-cell threshold.
- Window cleaning cycle care: The Winbot W733 runs a continuous load profile — motors, suction, and navigation draw simultaneously throughout each session. Avoid interrupting a mid-cycle run to recharge; partial discharge into a warm cell accelerates capacity fade faster than completing the cycle first.
Why the W733 loses suction and wall grip before the battery indicator drops low
The W733 runs suction and drive motors in parallel. When the cell voltage sags under combined load — especially on a worn or partially degraded battery — the suction motor drops output before the BMS triggers a low-voltage warning. The indicator reads remaining charge, not actual voltage under load, so the gap between "apparent charge" and real delivery widens as the cell ages. A replacement cell at full capacity closes that gap and restores consistent suction pressure across the full cleaning path.
Replacement battery not accepted by the charger after fitting
The W733 charger communicates with the battery BMS before beginning a charge cycle. If the replacement cell has been stored in a deeply discharged state, the BMS may present a voltage too low for the charger to initiate. Connect the battery to the unit first and attempt a short power-on — this wakes the BMS. If the charger still won't start, measure the pack voltage at the contacts; anything below 9V requires a low-current pre-charge recovery before normal charging will begin.