Ecovacs Deebot M82 14.8V Replacement Battery UR18650ZT-4S1P-AAF

Ecovacs Deebot M82 / Deebot 500 — 14.8V Li-ion Replacement Battery (UR18650ZT-4S1P-AAF)

This is a 14.8V, 2600mAh (38.48Wh) lithium-ion replacement battery for the Ecovacs Deebot M82, Deebot M82UK, Deebot 500, and DM82 robotic vacuum cleaners. It slots into the battery compartment on the underside of the robot and powers both the drive motors and the onboard navigation system. OEM part numbers covered include UR18650ZT-4S1P-AAF, BL7402A, INR18650-M26-4S1P, 20001088, and 10001088.

• Deebot M82 and 500 series fit: These models share the same 14.8V four-cell series architecture and use an identical connector pinout and BMS handshake protocol — that is why one battery covers all variants listed above, including the UK market M82UK.
• Bench tested on actual hardware: We ran this cell pack through full charge-discharge cycles on the Deebot M82 platform. The BMS correctly triggered low-voltage cutoff at the expected threshold and communicated state-of-charge data to the robot's indicator without errors.
• Dock charging habit on robotic vacuums: Do not leave the Deebot sitting on its charging base permanently between uses. Continuous trickle charging accelerates capacity fade in Li-ion packs. Charge to full, then remove from the dock until the next cleaning run.

Suction dropping mid-cycle before the battery indicator reaches low

The Deebot M82's brush motor draws significantly more current when the filter is partially blocked or when carpet fibres restrict airflow. When current demand spikes beyond the BMS's sustained-draw threshold, the pack drops its output voltage under load — even if the indicator still shows a healthy charge. The robot interprets this as reduced motor demand and cuts fan speed, which the user sees as a sudden suction drop. Clean the filter and check the brush roll for hair wrap before concluding the battery is at fault.

Robot returns to dock far earlier than expected on a new replacement battery

A freshly installed Li-ion pack sometimes completes only a partial cycle on the first run because the robot's charge-state calibration is still mapped to the old, degraded cell. The onboard controller estimates remaining capacity from voltage curves learned from the previous battery, so it reads the new pack as depleted sooner than it actually is. Run two to three full charge-and-discharge cycles to let the controller recalibrate its voltage-to-capacity mapping. After that, the dock return timing should align with a full cleaning cycle.