Top window cleaning robots HOBOT-2S, HOBOT-298 and HOBOT-388 have an internal UPS (Uninterrupted Power Supply) battery for safety reasons. But are they cordless? The answer is NO. These automatic robot cleaners for windows have to be plugged into a functioning power outlet at all times to operate.

So what is the purpose of the UPS battery? It’s a safety feature to prevent the robot from falling in case of a power outage. It gives a user 20 minutes to remove the robot off a window before a fall. That’s why it’s important to fully charge the battery before use. Power outages are rare in the US, but they do happen, and any quality robot window cleaner should have this safety mechanism. As soon as the power outage occurs, a HOBOT window cleaning robot starts beeping to alert you of the loss of power. Emergency UPS battery kicks in to keep the robot at a vertical position, safely attached to the window with the fan suction fully operational for 20 minutes.

It’s reasonable to ask why not make a robot window cleaner cordless? The answer is safety. A powerful robot window cleaner such as HOBOT-2S with ascending power of more than 15 lbs. requires a lot of energy. The battery to provide sufficient energy would be too heavy and large to maintain the vertical stability of the robot.

How about windows that are high and far away from the power outlet? How does a window cleaning robot reach them? HOBOT window cleaning robots come with a long power and extension cords (13 feet). Extra extension cords are also available for purchase to extend the reach even further.