I just wanted to get confirmation on this to be sure before proceeding.  Looking at my battery it *appears* to be low on water.  My question is; do I just fill it up to the upper level line?

I drew a black line to show where the level currently is;

The level should be between the the upper and lower lines. When your topping up fill it with distiller water to the upper line. Then next time top it up before it get past the lower one. 

If the battery starts to get old then replace with a glass mat (AGM) one forget about having to check water levels 

Thanks very much, will do that.  I just pulled it out today for the winter which is when I noticed it was low.  I literaly look at my battery twice a year and never think about it. 

If I recall correctly, you're supposed to charge it before you top it off. The water level falls a little when discharged.

But that's only if I recall correctly.

Ok, well I just removed it today to store inside for the winter.  So maybe I'll just leave it as is and in the spring after I put the charge on it I'll top it up.  Thanks again.

Double check what I said... I'm not a battery expert.

I did

I'll have it on a trickle so I'll top it up to proper levels.

http://motorcycle-intelligence.com/battery-maintenance/777/

Awesome. Glad to know I'm not leading anyone astray.

Call me crazy, but aren't you supposed to fill a battery with battery acid? I know the more water you put in the more diluted the electrolytes get with internals and the battery holds less of a charge. You can pick up a small container of acid from auto zone for like $5. I know I ruined a battery a few years ago by adding water and the durn thing would hardly turn over during the winter even after being on a trickle charger all night. but that may have been my bad experience and may have accidentally added the wrong type of water. trying to figure things like this myself..always something new to learn.

A battery's fluid is not all acid. It's a mix of acid and water (yes, a more diluted acid). The water evaporates over time and needs replacing. Enter the distilled water. Have a read... http://en.wikipedia.org/wiki/Automotive_battery 

Michael

I tried to check the fluid level in the battery last night, but couldn't determine at all where the fluid line was... Am I supposed to disconnect and remove the battery to check it? how about to fill it with distilled water if it needs it?

Take it out, put in on a flat surface and check 'er out.  I saw that mine was low so I washed off the top, and took one plug out at a time and pour distilled water onto the battery until that one was filed to the right level.  Then replugged and moved onto the next one.  Worked well without a funnel. 

 I usually shine a flashlight into one end of the battery then look at the opposite side, and that usually shows where the water level is in each cell. Won't go into a whole chat about optics, but that works for me.

I don't get too fussy with filling. I have a small hole in a bottle top. Fill bottle with distilled water, align hole over battery opening and squeeze. When it overflows I stop. Sure it may be a Tad too high, but so far the battery has served me well for three years and 53,000kms 

Michael

If your getting over 3 years in any battery your doing well. And add water as necessary when it needs topping up and ride it.