Well the bike is brand new so I took it to the dealership and they told me that i do not do enough highway driving and that is when the battery charges. To me that sounds like" hey man its friday afternoon and i dont want to work on it."

Is it true that the battery will not charge at low speeds like in town driving?

 

To a degree, that's true.
Sometimes a bike starts easily, like on the first revolution. Other times you have to stay on the starter a bit longer before it fires. The longer you stay on the starter, the more power that gets sucked out of the battery.

The single phase stator in a Sporty doesn't start putting out enough current to actually charge the battery until you're in the 2000 - 2500 RPM range. The charging system's output increases with RPM. The charging system first has to put out enough "juice" to power everything electrical on the bike and only then can it have a surplus of power to charge the battery. During time spent in idling or stopped traffic, the battery will be discharging.

On average, it takes about 20 minutes at "cruise" RPMs to replace (recharge) the power that was sucked out of the battery to start the motor.

If your running a lot of short trips, I recommend keeping the battery on a float charger (Battery Tender) when your not riding it. Do Not use a "trickle charger".

 

BTW, you never posted any voltage readings, do you have a voltmeter?
What voltage do you measure across the battery terminals with the bike running at a FAST idle?

If you can't perform that simple test, I guess you're going to have to take the dealers word for whether or not you have a problem.

 

The bike is at the dealership right now and they are checking everything out. Its still under warranty so i am going to use it while i have it.

Everything you said makes perfect sense. They just didn't break it down like that for me. I appriciate all your help and explaining everything. I guess i will have to go and get a battery tender.

 

Same problem here for me too. Brand new bike and mine started giving me low voltage signs on my way home this evening. I'll check my battery cables, etc tomorrow.

 

Mine ended up being a voltage regulator. The stealership replaced it because it is under warranty.

 

Guy's there is a service bulletin that just went out last week.......Voltage regulator's are bad in 2012 bikes........6 months plus worth of production had bad ones in them out of the factory.......New " fixed " replacement models are starting to be shipped to dealerships in very small quantities........on 6/18, Mine is getting replaced on the 20th........I call this a recall, but no factory Harley person will........just get in line, early bird gets the worm

 

what year bike was yours I’ve been at this issue for a month now

 

You realize this is a 7 year old thread?

 

So who cares. This message board is for folks of like mind to share information and ideas. I also have a 2009 Dyna, it went through the exact same issue. Not only was my voltage regulator a bad one that replaced the original, it was replaced for free. The dude is was just trying to fix his bike. If it bugs anyone that one would respond to an existing thread rather then get told to use the search function and sift through a bunch of retarded comments about thread age or butt hurt over a disagreement on any given topic. Why not just answer the question or don't? whichever, just stop crying about it. I thought this was all big tough 000.1 outlaw sons of anarchy bad *** bikers, not internet volunteer time cop mods.


That said, here is what I did when my lights came on, I did my standard pre trip check, then went a little deeper. Took off the battery box, followed the battery cables all the way down, found a nick in the positive wire, replaces it, bike ran awesome. Lights still came on. I had a mechanic trade me services, I built his work stall, he made sure the bike was good. So he changed the oil, and tested everything. It was the voltage regulator, he replaced it. The absolute best information that came out of the parts of this thread I read was the advice to get a tester, and know how to use it. Ill add that I had to learn to check the nuts bolts and screws quite a bit. Stuff gets loose on motorcycles.