Battery disconnected from car should read 12.5+ First check. 10 . 2 sounds like it has a dead cell.
If it shows 12 disconnect and 10 connected .Im checking the ground to the head under turbo. Running should be 14.6 in a perfect world.
Battery should show 12V start the car if it remains 12 its alternator if it goes below 12 to 10 there is big Courant draw along wit a bad alternator.
I can't believe Eric has made three bad chips I don't think he could make 1 bad one.
Lets put the ECU and chips aside for now
Lets charge the battery for 4 to 6 hr. and have it load tested. When we have a good battery let's find where the big voltage drop is coming from.
we have to have a good strong 12 v or nothing will function correctly.