External hardware and memory
Cables – Essentially all action cameras include the USB cable needed for charging the battery and transferring files. A few cameras with an HDMI output also include the HDMI cable. Cables are cheap and widely available. Don’t let the exclusion of certain cables influence your purchase.
AC adapter – There has been a recent trend to exclude the AC adapter from camera packages. For some shoppers this will be a blessing – they have plenty of adapters from their mobile devices. Others need the adapter and consider its absence to be a cheap move by the manufacturer. You can decide if you need one but even if you do and your preferred camera lacks one, adapters are pretty cheap and widely available.
A note of caution about adapters – For US-spec cameras that include an AC adapter, look for the Underwriters Laboratory (UL) symbol on the box and the adapter itself. Although a UL listing is not mandatory it does offer assurance that there is a near-zero chance the adapter is faulty. I know of at least two non-UL listed US-spec adapters that severely overheated and in one case began emitting smoke. That is a fire hazard you don’t want at home, work or anyplace else.
Spare batteries and external charging docks – Battery operating times can be quite short for action cameras depending on the settings – ranging from 50 minutes to 2-1/2 hours or so – and the battery recharging times are long – from 2-1/2 to 5 hours. Therefore some people consider spare batteries to be essential. If you do then you’ll want an external charging dock as well. A few action cameras include one or two spare batteries and the external charger. Most have them available as an option. Just a few action cameras have non-replaceable batteries. Nearly all the batteries are proprietary. Almost no action cameras use standard battery sizes like AA or AAA. Sometimes spare batteries can get relatively pricey because they’re proprietary. You’ll have to decide if you want them and how it affects your budget. A cheap and versatile option is to buy a USB power bank instead. Most cameras and power banks are compatible.
Memory cards – Nearly all action cameras use some version of a microSD card for their memory. Very few have internal memory only. Some cameras can only handle a maximum of 16GB of memory (microSD). Most can handle 32 GB (microSDHC) and some can handle 64GB or even 128GB (both called microSDXC). Most manufacturers specify that the card should be at least Class 10 (a measure of the data writing speed) and should be a name brand – no off-brands or generics. A few camera makers include a memory card with their camera. But sometimes cameras misbehave even when you’re using the right memory card so there’s no way to know if the card or the camera is defective without trying a different name-brand card. Memory cards aren’t too expensive so don’t worry if your preferred camera is packaged without one.
Global positioning system – Some of the higher-end action cameras have built in GPS,which enables you to geo-tag your photos and videos and also show the entire you hiking or running path that overlays the video. While this feature sounds like tons of fun, make sure to think whether or not you’ll really be using it, as GPS usually increases the final price by large.