My version of a DSO-150 case & battery pack. The sloping front makes the display easier to read IMHO, and the batteries make it 100% portable, ideal for Car problems.
Before choosing the DSO-150, I tried other el-cheapo DSO's, and found the DSO-150 is the best value/performance. The DSO138 has too much noise, plus the DSO-150 has easier to use controls and some LCD protection with it's built-in case.
The batteries I used are 2 18650 LiIon cells, pulled from a dead Laptop battery pack - one charge should last 15-20 hours, I also included a balance charger socket at one end - designed to plug-in one of the excellent BC-4S15D balance chargers - which could be left in if you neeed the DSO on for several days.
I consider the best BC-4S15D balance charger around, they are great, with a digital display of each Li cell voltage, and I've never had one cook a battery, all for $15.