Are capacitors really necessary?

[timmykim7]

Hi, what I understand is that most dashcams in the market come with a capacitor or a lithium ion battery in it and it helps a dashcam lasts longer period by safely shutting off the system by using the electrical power saved in the parts.

But at the same time I see other dashcams that don't have any type of battery other than the RTC battery and they go for like good 3~4 years with no issue. (I've seen some go for 6~7 years as well)

is is really necessary to have either capacitor or a lithium ion battery in dashcam? if there's any other advantages of having a capacitor please leave a comment.

Thank you in advance.

 

[Nigel]

No, it is not necessary.

The advantages are:

• When the power is lost, the camera can correctly close the video files, which is required for .mp4 video files. Without the capacitor you would need to use .ts files, and then many people have difficulty viewing them.
• The capacitor allows the video currently stored in the buffers to be saved to memory card. Without a capacitor you generally lose the last 2 or 3 seconds of video, and if power is cut due to impact, that lost 2 or 3 seconds can be the critical bit of video that shows what happened and whose fault the accident was.
• If you have a battery then it can continue to record for a few minutes after the impact, which might catch something important, like the other person admitting fault.

The problem with a battery is that you can expect it to fail after 1 to 2 years of use, mainly because of high temperatures in the car during summer weather. Sometimes they last 3 years but you can't expect that. Supercapacitors will likely last 10 years, maybe more, we haven't seen many fail yet.

So all good dashcams currently use supercapacitors, and it seems unlikely that will change in the near future.

 

[Julian23]

The problem with a battery is that you can expect it to fail after 1 to 2 years of use, mainly because of high temperatures in the car during summer weather.

Agree, the heat difference in summer and winter is an absolute battery killer. It doesn't help that the battery is charged all of the time and stays at 100% until the car is turned off. This isn't good either

 

[Nigel]

Agree, the heat difference in summer and winter is an absolute battery killer. It doesn't help that the battery is charged all of the time and stays at 100% until the car is turned off. This isn't good either

They normally stay at nearly 100% even when the car is turned off!
Also, charging lithium batteries in sub-freezing temperatures kills them pretty fast.

 

[Julian23]

They normally stay at nearly 100% even when the car is turned off!
Also, charging lithium batteries in sub-freezing temperatures kills them pretty fast.

The batteries don't really like these conditions. No wonder they will fail.
I am happy that most brands don't use batteries anymore.