One of the best features on dashcams is the loop recording function which allows for a simple user experience as there's no need to empty the card when it's full to make room for more videos. While convenient, this has the inherent downside of overwriting videos that might be important and when that video gets deleted there's no way of retrieving it. Some cameras have features that help out with managing these important files easier such as WiFi, or dedicated event file folders and emergency buttons.
WiFi helps by letting the user pull over and download any important file wirelessly to their smartphone, by saving it onto their phone's hard drive the video is now backed up in a location where it won't be overwritten. Furthermore, because it's on the user's smartphone it's also easy to trim and share the video through e-mail, social media, or a file storage server. Our most popular WiFi dashcams are the Blackvue DR650GW-2CH, BlackSys CH-100B, and Thinkware F750.
Many dashcams also have built in G-sensors which are used to detect when there's a large shock or impact. Some events that might trigger a G-sensor would include hitting a large pothole, slamming on brakes after being cut off, and obviously getting into an accident. On some cameras, once the video file has been recognized as an "event" or "emergency" it will put it into a special folder that either doesn't get overwritten at all or only gets overwritten when it's filled up with events (such as on the BlackSys CH-100B). This means regular driving footage or parking footage won't overwrite an event.
That being said, the best way to preserve important video files is to keep an extra micro SD card handy. WiFi downloads can take several minutes per clip and it is not safe to access the WiFi app while driving. G-sensor or emergency buttons often only show the 5-10 seconds before the impact or button was pressed, this means it may not show all the events leading up to the accident which can be important in some cases. The user can also unplug the power to the camera and remove the memory card but this means they are not protected from the time of the event till the time they put a card back in and power it on.
That's why we're running a promotion this month to include at least a 16GB memory card with every dashcam we sell. We recommend keeping this card in your vehicle as a backup in case of any event on the road while driving. 16GB is not the largest card most cameras can support but it's usually enough to last you on your drive home from the scene of the event so you can ensure no footage is overwritten but still be fully protected. Be sure to do a safe shutdown and stop recording before ejecting a memory card, otherwise you will risk corrupting the last file on the card.
Around the BlackboxMyCar office, we all keep at least one extra memory card in our personal vehicles as sometimes there's something we catch on our drive that we want to share with our customers and don't want to risk getting overwritten. Having an extra micro SD card is also very handy when it comes to troubleshooting dashcams as defective micro SD cards are the leading cause of recording errors. Regular formatting is also recommended to ensure optimal performance of the memory card.
As a unique/extreme example, one of our customers who is an Uber driver in California actually keeps 7 micro SD cards in his vehicle for each day of the week using a medicine organizer to store them. This is helpful for him because the important footage for him may not surface until several days, if not weeks later. Should a passenger complain about his driving or allege any other misconduct against him several days after the ride, it will most likely be overwritten even if he ran a 128GB Micro SD card. Unfortunately, in an age of "the customer is always right" attitudes and passengers who will lie to get some reimbursement in the form of Uber credits this video footage can prove to be invaluable.