Dead battery???

Earlier today while riding home from a cookout, my bike started to loss power, and lots of it. It would break up at all rpms an I just wanted to get home. At one point when I came to a stop, with the clutch in, and the bike died. I was able to start it back up normally. Once I pulled in my neighborhood, same thing happened again while moving. Bike was dead but I was able to pop start it to get home. Once I got home, I was able to get the motor to turn over once or twice with the push button. Now, when I hit the pushbutton, I get nothing. Neutral light, tail light, and headlight still work. I don't have access to a multimeter today, thatll be first thing tomorrow morning. In the meantime though, what do you guys think? I did notice the PO never had the breather tube hooked to the battery and the lowest cell in the battery was maybe a few mm below the min level.