Wireless Carts

We are looking at using wirless carts within our organization. These carts will use a small foot print dell computer with a flat screen monitor. The network connection will be provided by a Cisco 350 series wireless cart. The cart will be full mobile with a battery. I am looking for a vendor to provide a battery solution that will power this cart for 8 hours with a draw of 5 amps. I will award points for anyone who can point me towards that VAR.