I think my electric scooter battery is dying!!!!?

I have a electric scooter and it says it goes 15mph top speed and can cover 8 or 10 miles or something. At first, I went to school with it and it is only 2 miles, but as time passed, the distance and my battery shortened every week. At first, I went 15mph all the way and came back (total distance would be 4 miles) and still had full battery. After couple weeks, it said half battery remaining and eventually now, when i just go 2 miles, it has low batter in red color. I can't even come back. My friend says that my battery is dying out. It also says that do not exceed 240lbs but I weight like 200lb since I am 6feet something. Is the battery really dying out? What should I do? Should I buy another battery. Well if I do buy another one, it is like $80~100 and what if it dies out again, than I have to keep on buying it. Help!!!!

The make of it is Schwinn S-500

Your battery could be bad, but there are a few checks you should do first.
Remove and clean the contacts at the battery, as they can cause it to not charge right.
Check on top for battery caps. If they are removable, check the water level. Only top up with distilled water.
Check your charging system. Plug it in and place a voltmeter on the battery posts. It should cut back at 14 volts and then stop at 15 volts. Always charge it fully to 14.5 volts and stop charging after 15 volts. A slow charge is best.
If you are buying a battery get a deep cycle that has the highest amp hour rating you can afford in that size.

Good luck and if you need any more advice e-mail me.

How you can check if the battery is on it's last legs is to switch on the lights if they gradually dim over about 15 to 30 minutes them the battery is on it's way out, if the battery can be topped up with distilled water check that the water is just over the top of the plates, if the water is low the battery will not take a full charge, it's also worth checking that the scooter is charging, to do this turn on the lights and start the engine the lights should go a bit brighter as the engine is revved up. If they don't then the problem is with the alternator.