I recently brought my PSP to a family reunion with a copy of Monster Hunter Freedom 2. Long story short as soon as I got there, the battery died on me and there wasn't any monster hunting that evening. So I did some research online to see a comparison between the battery life from all the portable consoles and realized that the 3DS (which I own and also has a bunch of Monster Hunter games) has a better battery life. I also found out that there's something called "MUGEN extended battery" which is an accessory that has almost four times the charge of a regular battery. What I couldn't find though was people selling them or any alternatives I can get. So does anyone have any experience with these? I want to know where can I get them, how much are they or if there's anything similar in case they are rare or discontinued? Any other accessories worth getting? By the way, I own a 3DS XL. Thanks!
Here's a video for reference -