Here is a charging cart that lets you charge up to 32 tablets at the same time. The TRIPP LITE 32-Port USB Charging Station Cart lets you store and charge 32 iPad, Android, and Surface tablets. Each port offers fast charging. You can connect your devices to a computer for syncing.
The cart has a steel construction and black powder-coated finish. You can lock it to prevent theft or tampering. More information is available here.