So I pulled out my cbr earlier this week for the first ride of the year. she started fine and ran fine, but about 7-10 miles down the road she started acting up: boggy revving up, wanted to die at idle. The next mile or so it got worse, I had to hold the revs at 3k-5k to keep it running made it all the way home and checked the battery; 8.5 volts. so I throw my 2 amp agm charger on it and it won’t take a charge. so yesterday evening I get a new battery and start her up, everything is going great and I run that same 10 miles. then this morning I take the bike to school and about halfway there I notice the blinker isn't working right, then it does the same thing: sputters at low rpm and finally shuts off.
now for the weird part; yesterday after I put the new battery in I started it to make sure it was charging. at idle I was getting ~14.5 volts at the battery. what could cause a brand new battery to die in less than 20 city miles and still get 14.5V