Thirty years ago, hunting scopes (a.k.a. rifle scopes) were pretty much optical devices that helped to zero-in on a target for a better shot. There were no electronics involved. Today, though, some scopes are complex electro-mechanical-optical devices with technical features to provide more accuracy farther down range. These will need batteries to operate.
In fairness, you can still buy a fairly inexpensive analog scope. But if you are a serious hunter intent on using only the best equipment and the most ethical shooting, you might want to invest in an electronic scope. Make sure you invest in good batteries, too.
More About Modern Scopes
A modern scope needing batteries is almost always an illuminated scope. What is an illuminated scope? It is a scope with an illuminated reticule. In other words, some sort of light source placed behind them illuminates the crosshairs placed behind them. Illuminating the reticule does not illuminate the target; it only makes the reticule easier to see when visibility is poor.
Illuminated scopes with no other extra features are pretty affordable. But if you want to spend $500-$1500 to get extra features, you can. Some of the most advanced digital scopes include infrared night vision, onboard camera, and even Wi-Fi connectivity. You can use your scope as both a hunting device and a camera to capture wildlife.
Hunting Scope Battery Types Vary
Hunting scope batteries are really what this post is about, so let's talk about them. As you might guess, battery types vary from one model to the next. We can tell the difference between models based on whether we can remove their batteries. Some can, others cannot.
A scope with a non-removable battery must be unmounted and plugged into a charger prior to use. Most scopes of this nature are charged with a standard USB port. The onboard batteries are lithium-ion, so they are good for 1000+ charges. As for removable batteries, voltage and form factor are not the same for every scope. Like any other digital product, there is plenty of variation. Let us start with scopes using CR123 batteries.
CR123s were designed specifically to handle high power needs with reliability and consistency. A hunting scope certainly fits the bill. If you have an electronic scope with all the bells and whistles, you'll want a battery capable of delivering consistent power at a comparatively high voltage.
It is important to not confuse CR123 with RCR123 batteries. They are two different types despite being the same size. RCR123 batteries have a higher nominal voltage. If you use one in a hunting scope that requires a CR123 battery, the higher voltage could damage the device.
Other Battery Types
CR123 relates to form factor more than anything else. That being the case, you can find hunting scopes that use other battery types. AAA and AA batteries immediately come to mind. So do 9V batteries. There really is no standard here.
The most important thing is to choose batteries with the correct voltage. In terms of capacity, higher is better for battery life. A rechargeable lithium-ion battery with a current capacity of 1500 mAh capacity will last longer than one with a 700 mAh capacity. Be sure to also check out power capacity, measured in mWh or Wh instead of just current capacity in case your product will lose function at lower voltages.
For our money, USB-C rechargeable batteries are the best bet. They typically offer 1000+ charge cycles, they charge in under an hour, and they are compatible with any USB-C charger and cable. You get particularly good power density and comparably long battery life. That is exactly what you need for a hunting scope.
Electronic hunting scopes are like any other electronic devices. They need batteries to work. Choose your batteries wisely as they will affect your overall experience. And, the ability to charge in the field from a solar panel or power bank may save you a long hike back to the truck if you find yourself with a dead battery.