My Battery is about 1.5 years old and I think its time to check the fluid level in it.
Any tips on how to check it and what to fill it with. I've never done maintenance on a battery before so I'm not sure where to start.

I do put her on the maintainer when the thought strikes me.

 

If it's almost full you can add distilled water. If it has much less fluid add battery acid. Don't fill past the line.

 

Pop the cover(s), check to make sure that all the plates are submerged. If not, add distilled water so your up to the level line and plates are submerged and charge it up.

Don't add acid.

In general, a wet cell battery is a mix of 65% water to 35% sulfuric acid. If your level is low it's because the water has burned or evaporated off. The sulfer is still there, but when discharged it just attached itself to the plates... without the proper mixture your electrolyte isn't holding power. If you add acid to a battery that's low on water, now your mixture is off. Not good. In general, if your battery is low on electrolyte it's because the water has evaporated off. Don't add acid.

Wenty

 

Plus 1 Wenty

 

if it has caps you can fill if not it's a non sevice battery. just leave room for expansion when it's being charged by not over filling like mentioned.