B&H has the Polar Pro PowerPole for $44.99 (reg. $99.99) as its Deal Zone deal for the next three days. It provides continuous power to GoPro cameras. Read my PowerPole Review. Check out the deal here at B&H Photo.
Recall that the GoPro HERO4 Session is an ultra-compact action cam measuring as a 1.5″ cube. It captures 1080/60p video, as well as the taller frame 1920 x 1440p video at 30fps. It can also deliver 720p video at 100 fps for roughly 4x slow motion when conformed to a 24p edit timeline.
You can find the HERO4 Session here at B&H Photo.