i-stack Battery Charging Uniti stack Space is in short supply these days. Thats why i team thought: why not use the vertical option towards the ceiling for charging your batteries? Now you can easily attach, hook up, and power your batteries without losing space! i power batteries and i charge are sold separately. With the i stack 6 you can charge up to 12 batteries at once, ideal for facility management companies with multiple i team machines on the go. Battery management system