If you have an Autel MaxiDAS DS708 scanner, and want to add a battery to your MaxiDAS for convenience and portability, this article may be helpful.
For less than $25 you can buy a rechargeable 12 Volt battery pack module with coaxial DC connectors off ebay and just use some Velcro and mount it on the the rear of the MaxiDAS. The unit I purchased came with a short length of a coaxial power jumper cable that fits the DS708 and the battery pack also has a power switch on it so you can actually keep the MaxiDAS from draining the battery when the DS708 is turned off.
I have not timed how long the unit can run, but it works well for quick jobs and if you need to power the tool up for other purposes and not be tied to the car or a power outlet.
If you need to use the rear stand, it is not a problem depending on how and where the battery pack is mounted. Looking at how I mounted the MaxiDAS DS708 battery on the rear stand can be used without removing the battery pack.
It fits neatly inside of the prop stand and just the power connection/wire slightly blocks the prop stand if you want to use it, but this is easily worked around.
Here are some pics of the process: