Posted by
sgtslag on
Oct 07, 2011; 5:11pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/New-to-forum-CB650-and-my-first-question-tp3381249p3403433.html
The readings indicate your charging system is working optimally. The only culprit left, is your 'new' battery, or your riding speed/RPM's, as discussed already.
With regards to your battery's voltage, you have to let it 'rest' once you take it off of the charger, or shut off the key, for around 20 minutes. The charging is a chemical process, which alters the composition of the spongy lead plates, within the battery's cells. It needs time to settle down, to give you an accurate reading of how healthy the spongy lead plates are. After being actively charged, the whole thing will hold a lingering, higher voltage for a while.
You can test the battery's resting voltage, or you can put a load tester on it -- either one will give a fairly decent answer. The load tester puts a short duration, heavy load on the battery, and checks the output voltage during the test: too low, and the battery is toast. It really doesn't answer the question of the original problem, unless the battery was bad out of the box.
When you got the battery, did you connect it to a trickle charger first, or did you install it, and ride? If it was not fully charged when you installed it, you could have killed it. This is a common killer of lead-acid batteries: users don't follow the preparation instructions, and so they cut the life in half, or worse, by using them without fully charging them, first! Most AGM sellers claim they are fully charged, and ready to install, out of the box, but I recommend trickle charging fully, first, to be safe. Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII