First thing you want to get is a regulated battery charger or battery maintainer of at least 90a if you be programming BMW and Mercedes from off the Maxi Sys Elite tablet , Other makes will require a Windows 10 pro laptop , purchased OE subscription, often a lock smith ID if you need to program keys as part of the programming procedure.
I got this and added 10 foot cables. I use IOTA DLS 90 all the time whenever the key is left on awhile for KOEO diagnosis. It's all metal outside and has open slots , so it's not a good choice for working outdoors uncovered in the elements.LOL
https://www.solar-electric.com/ioen12vo90am.html