14.4V 4000mAh Rechargeable Lithium Battery Replacement for Ecovacs Deebot N79, N79S, DN621, DN622, Eufy RoboVac 11, 11S, 11S MAX, 15T, 30, 30C Max, 15C, 15C MAX, 12, 35C

The battery works well and easy to install.

This battery replaced the original battery that had quit after two years. I bought an extra one, in case this one doesn’t make it two years. You never know when they’re going to phase out products.

it made my vacuum working like new

There are many batteries that claim to fit a eufy RoboVac 11S. I might buy this one again but you should know that . . . .I went out of my way to make sure that that I selected one with the voltage specified by eufy and with the leads coming out in the same location as the original battery. The RoboVac 11S spec states14.4 volts and that's how the new battery's box is labeled. However, the actual battery itself is labeled 14.8 V, and the leads came out the opposite side relative to the removal tabs. Nevertheless, it fits well and is working fine. I don't know about battery life yet. 103% battery voltage doesn't bother me as the contradiction does. I don't like sloppy labeling.

Excellent battery. I have an older Bissell, 1782 Pet Hair Eraser Cordless Hand and Car Vacuum where the battery pack was starting to go bad. Bissell no longer makes the NIMH battery pack for 1782 & there are no other vendors who supply it. With a couple of small modifications, this battery pack worked well. I tested it on overcharging, over discharging, and overheating. It cut power in all critical tests to prevent harm to battery or vacuum. Lasts over 2x as long as the older battery pack. Very pleased.