Battery life (runtime)
How many hours the device runs on a charge, by the maker's test. Real runtime is shorter in the cold and with Wi-Fi, recording or the rangefinder on.
What it means
Runtime is the maker’s figure for how long a full battery lasts, in hours. On this site most units claim between about 6 and 11 hours, with some as low as 2.5 and a few around 15. The figure is usually measured at room temperature, often about 72°F, with power-hungry features such as Wi-Fi, recording and the rangefinder off.
What it changes in the field
A dead thermal ends the hunt. An all-night sit for hogs, or a full night of calling coyotes from stand to stand, can run past the rated hours. Cold makes it worse: lithium batteries give up much of their capacity in hard cold, and owners regularly report a fraction of the rated runtime at 0°F. Streaming to a phone and recording video also drain the battery faster.
Battery types
- Built-in: cannot be swapped in the field. You recharge or plug in a USB power pack.
- Removable packs made by the device maker: quick to swap, but spares can be expensive.
- Standard cells, such as 18650 or CR123A: cheap and easy to find, and you can carry several.
Many units also take power from an external USB pack, often mounted on the rifle rail. Check the port type and whether the unit runs from the pack while its own battery is low, since some do not.
What to look for
- A removable battery or a reliable external-power option for long nights.
- Rated runtime well above the hours you hunt, to allow for cold.
- Owner reports of real cold-weather runtime over the box figure.
How we use it on this site
We show the maker’s runtime and whether the battery is removable. More hours scores better, but remember that each maker tests its own way.