Ecovacs DN620 Replacement Battery 14.8V 3400mAh Li-ion

Ecovacs DN620 / DN621 / CEN360 Series — 14.8V Li-ion Replacement Battery (ICR18650-26J-4S1P)

This is a 14.8V 3400mAh Li-ion battery pack for the Ecovacs Deebot DN620, DN621, CEN360, CEN361, and compatible models. It slots into the underside battery bay and reconnects to the same BMS harness as the factory cell. Voltage and capacity match the original 50.32Wh specification exactly.

• DN620 / DN621 / CEN360 series compatibility: These models share a common 14.8V four-cell architecture and the same battery bay dimensions. The connector pinout and BMS communication protocol are identical across the group, so one pack covers all of them without modification.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on a DN620 unit. The BMS handshake completed correctly, the charge indicator responded normally, and the cell voltage held within spec across multiple cycles with no cutoff errors logged.
• Dock charging habit for DN620 users: Do not leave the DN620 sitting on the charging dock indefinitely between cleans. Continuous trickle charging accelerates capacity fade in Li-ion packs of this size. Charge to full, remove from dock, and return it only when the battery is depleted.

Suction dropping before the battery indicator reaches low on the DN620

When the motor draws current against a restricted airflow — blocked filter, tangled brush roll, or a clogged inlet — voltage sag hits the motor drive circuit before the battery gauge registers low. The BMS sees elevated current draw and reduces output to stay within safe limits, which presents as a suction drop even on a freshly charged pack. Clean or replace the HEPA filter first and check the inlet path before assuming the battery is the cause. If suction recovers after clearing the restriction, the battery is not the fault.

DN620 motor cuts out mid-clean and then recovers on its own

This is an overcurrent trip, not a dead battery. When the DN620 hits a sustained blockage — thick carpet pile, debris packed against the brush roll, or a partially blocked filter — the motor current spikes and the BMS cuts output to protect the cells. The pack resets once current demand drops, which is why the unit restarts after a pause. Clear the blockage, check the filter, and confirm the brush roll spins freely. If trips repeat on a clean machine with a new battery, measure resting pack voltage — it should read between 16.4V and 16.8V after a full charge.