I put the tester on it and it says 2/3 but I also heard your suppose to run a battery dead before charging so what should I do and is there anything wrong with charging a battery on carpet and can anything dangerous happening cause ive been reading stuff that it can explose and cause blindness and stuff.. any info will be helpful

Deep cycle batteries should never be run down completely. This will ruin them very quickly. They work best if never discharged below 1/4. Recharging when it is 2/3 charged is perfectly fine. This is actually good for the battery

A battery will explode if not connected properly to the charger. Read the directions on the charger or get someone to show you how. They contain sulfuric acid and will cause you serious harm if they explode.

You should have a battery box to prevent any acid from leaking out onto carpets, etc. By US Coast Guard law you need to have the battery in a secure battery box to use it on a boat.