Hi there, Until recently I was using the Asus zenpad z380 with a powercase for a mobile jury of sports events. There is no power connection available at the location the jury is standing and for this, we used an original battery case that could easily be attached to the back of this specific tablet. I had the double amount of cases compared to the tablets so I could change the case of these tablets. Most of the time this was after 13+ hours of usage. However, this tablet is no longer for sale and neither is the powercase. With aging materials, I'd like to obtain new ones but that is no longer possible. Tablets should of course not be expensive. The ones I used were around 200 each. What is the best solution or alternative for this system?