1989 EX MOD Land Rover Defender 110 - Battery/electrical problems

Hello, fellow land rover enthusiasts,

I have recently purchased my first ever land rover, and around a week ago I decided to put a winch on it. due to the fact that i go off-roading alone a fair bit, my main worry when doing this is if i get stuck, overturned etc etc. so i decided to install a winch to the front of the defender. it's a superwinch 9.5 talon. so i installed it, tested it out and then drove to the petrol station for some fuel, on my return journey i lost all power and came to a stand still half way between a hill and a lay by.

today i tried to jump-start the defender but the battery kept sparking when i put the grips near it, so i decided to take the winch negative and positive leads off the battery which caused the sparking to stop and i was able to start the defender and take it a half hour drive around the local area, after i returned and turned it off it wouldn't start again.
now this is where I need some help. either my alternator is fried and isn't charging the battery anymore or the battery is fried and isn't charging is it the winch that has caused this? do I need a two battery set up? any help is much appreciated so i can solve this problem

Try a different battery. Your one may have e been on the way out anyway as the winch us just killed it.

If you're running a winch it is advisable to run a split charge battery system.
One to start and run and the other for the winch, otherwise you are likely to fry your only battery!
Make sure that the alternator is beefy enough to run the winch, otherwise you will drain off more than you use!