There are a bunch of different ways, and yes, battery power is necessary for them all.
One popular method is drop-and-retrieve, where you leave the gear (recorder and mics) secured in a location overnight. This allows you to put the most distance between yourself and any potential wildlife that will come around. This also allows for the most compact possible instance, easy for hiking-in and hiking-out. Just be aware that many animals are curious and will investigate your equipment. It’s a good idea to keep anything possible (i.e. the recorder itself) inside some sort of indestructible case that rodent teeth, large carnivore jaws, and curious primate hands can’t get through.
I’m fond of long mic cables myself as I like to listen while I record. My standard setup uses 90 meter cables, long enough to get away from my tent to where most wildlife in my area won’t be too skittish. I know folks using CAT-6 extenders that reach 225+ meters. I use this method with a Sound Devices MP6 (formally a Zaxcom MAXX) and external batteries. With a single high capacity USB-C powerbank (Anker 26800) the MP6 will power 3 mics and record well over 12 hours (close to 20 if it’s not cold).
If you need AC for your particular piece of equipment, you can try a dedicated product like an EnergyBar or Anker’s PowerStation, or you could even rig your own for lower cost by using a common 12V battery and a power inverter. Be careful not leave the power inverter out all night near your microphones, though, as most have tiny fans that will create noise.
Depending on your gear, you can get batteries that will easily run 14-20 hours or even far longer. For instance, you could use a Core battery with a P-Tap adaptor or an NP-1-style battery with either a cup adaptor or P-Tap if available for your particular piece of gear.