What's wrong with my ATV/battery?
 

I have a 3 month old 12v 6a motorsports battery I use to start my ATV. Recently it started getting weird and dying like every week - now when I plug it in, fully charged, to the ATV, when I turn the key it clicks/buzzes, and the wires by the battery and the screws get hot. And I mean ouch hot. It hasn't blown up, but I have no idea what the problem is - it started when I was riding my ATV and it stalled (I'm learning) and when I went to restart it it wouldn't restart, and after I charged the battery (it was dead) it still didn't charge - and now I'm here. Also, the battery reads 10ish volts on a voltimetre. Is it a battery or ATV problem?
Thanks!

PS - I bought a 12v motorcycle battery on amazon and tried that but it didn't work - I suspect its not enough amps, as its like 3/4 the size of the one I have now.

Welcome to the world of troubleshooting.
Possibly a dead cell in the battery but more likely a short in the starting circuit or the starter itself. I'm leaning towards the starter.

10 volts is a dead battery. You should see above 12.7, preferably 13.1. Clicking/buzzing is the starter solenoid when the voltage from the battery is too low to activate the starter. Wires getting hot is indicative of a heavy load on the circuit, possibly a locked up or shorted starter.

Try charging the battery and check it with a VOM. If you don't get at least 13 volts, try a different battery. With a fully charged battery installed, disconnect the big wire from the starter but don't let it touch any metal. Turn on the key and hit the starter button. Nothing should happen, no clicking/buzzing, no hot wires. If you get noise and sparks, you have a direct short to ground. You'll need to hunt that down and do some rewiring.

If there is no drama, turn off the key, reconnect the big wire to the starter, and repeat with the key on and hit the starter button momentarily. If you get the clicking/buzzing, stop and check if the big wire to the starter is hot. Also check the starter housing. If that's hot, too, that pretty much tells you the starter is toast.

What is a VOM?

A multimeter .

I just took off the plastics - there are like 5 million wires all going in circles... This is way more complicated than I envisioned.

need a new better battery,try walmart has worked for me. buy a least 10 or more lawn mower batterys and so far so good

First, it sounds like you stator or rectifier is bad. That's possibly killing your battery. Also, if it's not turning over, but getting hot, that's a mechanical issue. Something is keeping the engine from turning over.

Definitely battery has gone bad,could be your voltage regulator,
https://www.amazon.com/GOOFIT-Voltag.../dp/B00UCXFO6A
My voltage regulator went bad and was allowing to many volts to go to the battery and cooked my battery.I'm not much on sealed lead acid batteries but I went with a Mighty Maxx battery from Amazon and have had no trouble with it.Seems to be a good battery plus not expensive.
I check my voltage going to my battery every now and then hoping to prevent that from happening again.I check it not running then I start my atv up and check the voltage at the battery,plus turn the headlights on & check the voltage again.Voltage should go down a little when you turn your headlights on but should always be 13+ volts with the headlights on or off.