Won't start after cold spell

Hi guys, i have a problem, i can get a spark out of the battery but in the wrong place…

Seeing the impending cold weather i took the battery out of my bike and kept it indoors, now coming to start the bike after a couple of weeks of inactivity the lights and heated grips all come on but if i try to start it a spark shoots from the negative terminal of the battery and the power all goes off…

Is this the battery having run out from lack of use or is there something slightly more expensive up?

Thanks y’all

I am not sure I understand what you mean about a spark from the negative terminal. A spark from where to where?

Umm…you connected the terminals the right way round, right? :blink:

terminals are the right way round :smiley: and not sure where the spark went, there is a random metal shape (meant to be there) next to the battery and i think it went to that. I’d crack out a picture but i’m a long train journey away from it

For history’s sake it was because the terminals were too loose