Carry a spare battery. A spare battery is small and easy to carry. With Nikon, if you want to get a AF or AF-D lens, you are stuck with the heavier D7200, as the lighter D5xxx and D3xxx do not have a body AF motor to drive the AF and AF-D lenses. Weight can be a major concern. But only you can make that call. When I was younger, I could easily carry a 20 pound camera bag on a 2 week trip. Today, with age and injury, I can't do half of that. If you are traveling or going hiking or similar, both weight and bulk becomes a factor. For travel I switched from a D7200 + 18-140 to a micro 4/3 Olympus EM1 + 12-60. 40+% weight reduction and significant bulk reduction. And the reduction is even more with the lighter/smaller EM10. For LOW light photography, get a fast prime, like a 35/1.8 or similar. In LOW light, a fast lens beats a high ISO body almost every time. I have a fast prime as a companion to my GP zoom, specifically for use when the light level drops too far.