Hi guys. Sounds to me like this isn't a battery problem.
Follow the smaller battery positive wire to the under-hood fuse box. Be sure that connection is clean and tight.
If that isn't the cause, have the charging system professionally tested by a mechanic, not at an auto parts store. Specifically, I want to see what they find for "full-load output current" and "ripple voltage".
Friday, March 31st, 2017 AT 5:41 PM