[Bill H]

Sorry if this repeats other threads - but I'm looking for BMW (E93) diagnostics and coding Software - preferably the BMW stuff, and Im now confused by all the acronyms and jargon.
Nothing wrong with car - just got scared that a battery replacement will need a dealer visit, so I want this as a precaution.
I will probably install this on a windows laptop.
Theres loads on ebay all claiming to be the best and latest, and theres a vast range of prices
DO I need ISTA or INPA ?
ISTA p or ISTA d?
DCAN?
Do I need a special cable or will any OBD to USB cable do ?

Help please for a very confused bamboozled DIYer a simple recommedation would be appreciated.