"The a7 III uses the Z battery, introduced in the a9 and also used by the a7R III. It's good for 710 shot per CIPA ratings with the a7 III, as its power require

"The a7 III uses the Z battery, introduced in the a9 and also used by the a7R III. It's good for 710 shot per CIPA ratings with the a7 III, as its power requirements are less than the a9 or a7R III, both rated for 650 images per charge." All of my Nikon DSLRs (D5000, D7000, D750) can shoot between 2-4k images on a charge, and I use a mix of official Nikon batteries and cheap eBay knock-offs. In general the cheap knock-offs perform better. If I had to change batteries every 500-600 photos, I would be constantly stressed during a job and probably flip batteries every time I had a minute free. If that's not enough juice for a photographer, the battery grip will get that number much higher (and provide stability when using heavier lenses).