Mirrorless cameras use a lot of power, much more than DSLR cameras. You can expect maybe 2 hours of battery life with a camera doing something like mineral photography.
So AC adapters begin to make a lot of sense. Canon sells an AC-E6N for $88. This is just a perhaps overpriced, but presumably well engineered "wall wart". You also need to buy a DR-E6 camera adapter to go with it for $50. This brings the total up to $138. You need the camera adapter because it is the plastic pseudo battery that fits into your specific camera. Presumably Canon uses the AC-E6N for a variety of different cameras, and they each have their own compatible adapter.
The AC-E6N generates 8.4 volts. This is because the LP-E6 battery is just a pair of 4.2 volt Li-ion cells in series. The battery is marked on the side as 7.2 volts because Li-ion cells are 4.2 volts fully charged and about 3.8 (or 3.6) volts at half charge.
As a side note, I have been using Wasabi Power BTR-LPE6-JWP batteries with complete success and satisfaction for many years. They are actually rated somewhat higher in capacity than the genuine Canon cells.
Being cheap, and perhaps foolish, I balked at the $138 for the Canon setup and purchased a Watson CA-CB1 unit for $18. These are still sold by BH photo, so they can't be complete junk. But I wonder about risking my expensive R5 camera to save $100. Nonetheless, one can only be a bit surprised that the Watson is less that 1/10 the cost of the Canon unit.
Tom's Computer Info / tom@mmto.org