Ive been running the newer Pulsar Thermal XP3, 640 core, ran just a tad over 4K on sale w/free shipping. Has onboard recording/picture, picture in picture viewing, many options on reticles, options for different ranges, or other guns if you move it gun to gun. Very sharp viewing, easy to operate, has removable rechargeable battery, can charge in the vehicle via USB hook up.
Like many thermals you can shut off the display and it comes right back on when ready on a stand.
I usually leave mine on all the time on stand and made a lens cover to block the light off the back end when its in my lap.
You can buy a backup battery 20hr pack as well as the standard pack OR use a battery pack if you plan to run it consistently. The basic battery has lasted me all night long o far.
I have 103 coyotes to it since I got.
I went with the 640 core since I do a ton of predator control at night on private ranches.
My pal runs a FLIR PS32, 35mm thermal, internal battery, does run off backup battery attached to rifle if needed, charges vis USB from your vehicle. I feel there are many newer thermals that outshine it & cost a lot less as stated above
No matter what you do get Id definatley make sure you can replace the batteries instead of an internal battery you cant swap.