Amazon has the Honeywell Cordless Window Cleaning Kit (HWC300) for $26 with free shipping. Temporarily out of stock, but can still be purchased. Home Depot has it for the same price.

Includes a lithium-ion battery, a 3.6-volt charger, detergent applicator, 11" and 7" squeegees, belt clip/wall mounts, and microfiber pad.