Battery capacity is going to be a constant hurdle that you need to get over in Tears of the Kingdom. Any machine you build will quickly drain the battery as it gets more complex. The legitimate way to increase battery capacity in Tears of the Kingdom takes a lot of time and effort. This glitch makes the process a lot easier!
In order to perform this glitch, you will need to use the same method used to farm infinite diamonds in Tears of the Kingdom. You will need to make sure Large Zonaite is the last item in your inventory. Do this by taking them all out, throwing them on the ground and then picking them all back up again.
Once all of the Large Zonaite is the last item in your inventory, find an area to jump and open your glider. While you are in the air, find an item in your inventory that you have x1 of and hold it. Then go down and hold as many pieces of Large Zonaite that you can. Press B to exit the inventory menu and you will drop the items below but you will find that they are not removed from your inventory. This will give you an infinite supply of large zonaite. The video below will explain this in more detail.
Once you have a lot of Large Zonaite, you can visit the stores in the underworld to purchase all of the crystalised charges that they have for sale. Once you have all of them that you can buy, you can return to a battery upgrade station and purchase as many battery cells you can. Rinse and repeat until you have fully upgraded your battery.