Ebay is ur friend

get a replacement battery for the gamepad right off the bat the stock battery sucks ass in terms of battery life

modify the gamepad battery, i did a mod for it with a pack of 7800 mAh physically, and did some mods to the motherboard so it can be recognized and charged, its peak, my battery lasts 6 hours straight when fully charged

If listings on Ebay are too much, checkout "JPfans". Lots of super cheap japanese consoles if you're willing to mod them so they can be region-unlocked