Salvage yard battery

Need help computer does not like battery pack me and my brother put together,it is a gen 1 upgraded to a gen2 pack,any ideas most appreciated.The best time is about 3 hrs before it kicks codes,I can usually unhooked the battery to reset the car,
WHEN WE got the car a year ago it had been sitting a year,then six months before we got it up and running $1,800 later and 40 hrs later she runs,been driving for about a month,love the car only had to call my brother for a jump once after a short test drive,started right up and have not had to jump since,new Wal-Mart battery IBelieve,Never left me stranded since,someone mess with ingintion switch never got both screws tight might have to try and tighten again,starts and runs after reset for about 10 miles,battery on screen goes halfway than full that is usually the time the red triangle and check engine lite comes on,Sometimes I can turn of 10 seconds and resets,Sometimes I have to disconnect the battery,
WHEN it gets hot the abs,brake light comes on and you can here a scraping noise coming from the engine compartment.I Belive that is all my problems for now?Any advice will help,over 40 years turning a wrench but this is new to me,had a lot of old cars out of necessary,this is the newest car I have ever own,SAD but true and I still love my Prius
Old saying if you do not like a prius you have Never own one are you have lots of money for gas!!!
Thanks in advance for any help Richard.if this is wrong place tell me where I need to put it?