It is basically a mini PC, I brought it online.
I had removed the housing of the Mini PC, only mounted the main PC board into the Box, well it saved a lot of space to me.
If the link does not work, i am sure you can find similar one on the ebay and amazon.
For the screen, i had some PVC blocks mounted inside the cap (by using 502 glue), each PVC block has a threaded holl on it, the monitor was placed on the center of the cap with 6 PVC blocks around and some soft foam blocks supporting on the back, so when i finally place the aluminum cover on, i can kind of push the monitor in a little bit then fix the cover by using 6 screws. Since the monitor was compressed between the foam blocks and the aluminum cover, so it it solidly fixed.
I have roughly tested the running time after a full battery charge, it is about 5 hours.
It depends on how much background apps running on the mini PC, the PC consumes the power most.
I believe the running time of the Topside will longer than BR2 anyway, so i am ok with it as long as it can run over 2 hours. And i can plug external Dc power on once the battery died.