If you really want to know, take it out and charge it 24 hours. Then carry it to Autozone or Harley shop and have them load test it. This will show you how close it is to the rating it should be.

My experience is it does tend to take some life off the battery. You are only getting so many starts out of it and that got a lot of them. Bet it still will go couple years if it still starts fine.

Like others mentioned, I do not use the off switch either. Not one in my car and have yet to figure what circumstance I would need it on a bike. Harley sure says to use in in their owners manual. The Internet says it's designed to be used at a signal light leaving your lights on to lower fuel consumption and emission rate and an emergency if the bike is dropped. All modern Harley now have a bank angle switch to cut them off and are pretty clean emission. To me, it's safer to be ready to go when the light turns green.
Harley ought to take it off and save a few bucks.

 

And there it is. Buy a new battery, put the old one in the garage with the receipt taped to it (so you'll remember what it cost) and stop using the kill switch. I swear the MSF must have stock in Deka or Yuasa.

 

ROFL!!!!!!!!!!!!!!!!!!!!!!

The MSF is good for one thing..getting a motorcycle endorsement in some states. I guess you could add lower insurance rates possibly, depending on what company you have.

BUT!!! After you get that endorsement, find a Motorcycle Cop and pay him/her $100 for a training session one Saturday morning. They will quickly show you how to use the REAR BRAKE to maneuver that bike, not the front one. Trust me, it will save you a lot of money! By learning how to NOT drop your bike, you will save money on broken parts that need to be replaced, AND, on Doctor visits for back problems from having to pick up that heavy sucker!

 

When the battery is drained below 10.2 volts over a constant voltage drain like that the battery will lose half it's life. You should still be OK to use it but don't expect 3 more years out of it. Keep an eye on how the bike is starting, if it seems to start to drag (turn over slowly) while starting it I would start thinking about replacing it.

 

In the old days harleys used to get the "dreaded click"sometimes when you hit the starter and the only thing you would hear is a click.there were many reasons this happened but it seamed that if you used the kill switch every time you shut it down the frequency of the dreaded click was minimized.I have not heard of any newer bikes having a problem with this.So therefore i'm not sure why its still installed on harleys.I use it all this time because its what i have done for many years, habit i guess.

 

I left mine on for a week. The battery was DEAD - tender would not even register it. I used jumper cables and connected it to my car battery (car not running) for about an hour to get a partial charge, then put the tender on for 24 hours. It has been fine so far on multiple short rides, but I will replace the battery before my next long road trip.

 

You are not the first nor the last. Unless the battery was already near end of life it will likely be just fine.

 

battery is fine been a mechanic for 25 years . a total drain will not harm the battery in anyway. just give it a full trickle charge and move on lol.

 

Curious where you got that fact? Ive been a mechanic since 1986 and the misinformation I read never ceases to amaze me.

I didn't see anyone ask what kind of battery it is. Is it a fiberglass matt or lead acid?

Theres a term called exercising a battery where you drain it and recharge it, its good for the battery contrary to what many are saying here. Killing a battery in the dead of winter and allowing it to freeze rock solid is another story but in this case I would charge it as he did, ignore the fear mongering and carry on.

We would have to be psychic to know how long a battery's life is in the first place to know that we actually shortened it by draining it.

 

Well it is a fact that draining a battery below this voltage accelerates the growth of Lead Sulfate on the internal plates. Build up of Lead Sulfate is EXACTLY what makes a battery eventually worthless. Lead sulfate builds up on the plates during discharging and charging, but at a very slow rate, hence you get several years typically out of a battery (depending on the make up of the battery as you stated). I assumed (maybe bad on my part) that this was a lead acid battery. So tell me what part of this explanation is "Mis-Information"??