an unexpected bonus after replacing 12 v. battery!

I self drifted my thread on "carrying an ebike in a Prius", into how I discovered my acc battery (original, 2013 PIP) was shot, so I won't go into that again. BUT, to my surprise, the first time I fired it up after I replaced it before heading into town, with the usual full charge, I was very pleased to see I had pickedup 3.5/4 miles on my EV display! I had been showing 10+ the last several months, and thru the winter, though when I first bought it, used, it used to be 11+. I suppose the HV battery was working overtime keeping the little battery topped off? Whatever, don't care, but I'll take it, a very nice surprise. BTW: my commute to my crane yard is 13 miles, with a 1200' vert descent, I usually get there with 3 or 4 miles left "in the bank, today it was almost 8.