There once was (maybe still is) a problem with the battery ground cable connection. As a matter of habit, I always remove that connection and clean it up once a year. I know you found a dead battery, but this could be a future problem. I've been with riders that had them go completely dead after a gas-stop. Use to be a regular check with the HD mechanics. They'd have a lot come in with loose or corroded battery ground connections. Just seeing it happen to a couple of other riders convinced me to check mine often.

 

I certainly wasn't complaining. But as soon as I saw the receipt and realized the battery was that old, I knew what the problem was.

 

Really appreciate all the replies fellahs. Got a new one in and back in business. Gonna go pick up a multimeter just to be sure I'm reading right and don't have some other variable playing on the new battery. That said, but now I'm at this point I'm pretty sure my battery life was just done. Seems like you bought one summer-before-last and go find what you thought was two years is actually four years.

 

I'm not advertising (and you have a new battery anyway), but just for future reference.
I purchase batteries on-line and they will ship one right to your door....THAT FITS and has more cranking-power. Have not purchased one recently, but the price was cheaper than at the dealership. I am an hour away from and dealer anyway, so shipping one to my door is much cheaper for me.

 

1550vt, Mine was $107 after tax. Not sure what the dealers want since I don't darken the door unless I have to. Found one at Hunter Batteries in OKC. Was hoping to find one made in the USA (I know it does not mean what it once did but still important to me if I can find it) and this one fit the bill.
Connectors at the posts look good - I didn't trace down the ground but will be sure to have a look. Thanks!

 

You don't have to look very far. The negative battery lead is connected to the inner primary almost directly behind the starter. A long extension and a hex-head socket will reach. Take it lose and use something like crocus cloth or sandpaper to clean up the mounting surface and the end of the cable. May not ever be a problem, but it will eliminate the chance of having one. This use to be an almost habitual issue and one of the first things the mechanics did when they uncrated a new bike off the truck was check this connection.

 

My last $80.00 Adventure Power battery lasted 7 years in my 99 FXSTC. The one in it now is from Walmart at the same price. We will see. When ever I have a low battery I always charge it up and start the bike to see if the voltage at the battery is at least 13 volts. If not your charging circuit has a problem. Another problem on HD's is the ignition switch. They can be cleaned.