"New" 3ds battery replacement

Recently I decided to repair my “new” 3ds as the micro sd card slot used to fire out the card however upon replacing the sd card slot I noticed the battery I had been using was heavily bulging and needs to be replaced, the issue being as this is a “new” 3ds and not a “new” 3ds XL finding parts for it is tricky enough. With enough searching I found a site selling the micro sd card slot I needed however the battery seems even more difficult as all batteries I can find seem to be less powerful and overall worse then the battery sent with it and a lot of the sites and means of obtaining a new one seem fishy to say the least.

Finally bringing me to the question does anyone know of somewhere I can purchase a new reliable and decent battery for my “new” 3ds?

You should be able to find a reliable one on ebay