I've recently had a strange experiance with charging. When I had an old factory battery, charging voltage on Cobb AP was 12,5-14,14. A week ago I observed occasional drop of charging to 10. I went to Subaru dealer and it turned out to be the dead battery (after 6 years...). I got also an inspection af the alternator and everything was ok. After installing a new battery (BOSCH EFB with equal parameters with the factory one) the charging came back to 12,8-14,14. But the other day, after a long journey it ocassionally dropped to 10,8 or sitted at 12,6 and by WOT came back to 14,1. The same when ligths on. The Subaru Dealer again made an inspection and everything was ok. I was informed that my alternator is "smart" and keeps my battery in good condition not charging it all the time. And now I can see on my AP very different values. Most of the time 13-14V, but sometimes 11,8-12,6 with momental drops to 10,8. So far I didn't know about that. Do You have the same?