Supercapacitor vs. Lithium Battery — What Matters for Dash Cam Heat Resistance?

[Becky_70mai]

A dashcam installed inside a vehicle can face significantly higher temperatures than most consumer electronics.
For vehicles that are regularly parked outdoors, especially during summer, the power system is an important factor to consider when choosing a dashcam.

 

[Becky_70mai]

One of the key differences is the use of a lithium battery vs. a supercapacitor.

1. High Temperature Resistance​

Lithium batteries are more sensitive to prolonged exposure to high temperatures. Repeated thermal stress can accelerate battery degradation and, in extreme cases, cause battery swelling or other safety issues.
Supercapacitors are designed to operate more reliably under high-temperature conditions and do not rely on the same chemical energy storage mechanism as lithium batteries. For a dash cam that spends long periods inside a hot vehicle, this can be an important consideration.

2. Long-Term Reliability​

Lithium batteries have a finite charge-cycle lifespan and naturally degrade over time. High operating temperatures can further accelerate this degradation.
Supercapacitors can withstand a very large number of charge and discharge cycles, making them better suited to applications that require frequent power cycling over a long service life.

3. Parking Surveillance​

Parking mode places additional demands on a dash cam because the vehicle may remain parked for hours under high-temperature conditions.
A heat-resistant power system can help improve overall system reliability during repeated parking and recording cycles.
For drivers who regularly park outdoors, especially in hot climates, the power architecture is therefore worth considering alongside image quality and parking features.
Therefore, lithium batteries provide more power, supercapacitors handle heat, and last longer.

 

[SafeDriveSolutions]

What about having a dash camera that has neither a battery or a supercapacitor?

 

[kamkar]

That also seem to be a option these days.
i am also wondering if newer lithium type batteries will fare better in the extremes.

I am a bit worried about my 70mai power pack, NOT that i think it is inferior to anything else really, but just as a long time RC guy i have seen lipo batteries cook off, but hell also Nica batteries go KABLAMO now and then in the old days.
And i think for most of us all, the car we have is a significant investment.

 

[qusejr2]

What about having a dash camera that has neither a battery or a supercapacitor?

The main reason why DVR use battery or supercapacitor is that protecting file system corruption (whent the power off case). Both of them(supercap and battery) can be performance degrade earier than expected (cause the operation condition is too worst) In case of supercap , even it has more good registance of heat , the internal temperature of DVR almost over 80 C, it make swelling and performance degrade sharply. the DVR have to work with same operation quality at least 3years. normally 5 years.( excep SD card). The battery and supercap may not last that period with hot evironment. DVR write data to SD card at any time(except parking mode), and during power off sequence if there is no insufficient power to complete current writing file, the filesystem may be corrupt. the power off sequence occur everyday. the sufficient power supply is very difficult in case cigarjack power . ( car battery and external battery can do). So DVR have to recovery filesystem. ( I mean, make complete the file which created during power off sequence). this is based on pratical and long term experience. The most critical priority is to ensure continuous recording, and to achieve this, file corruption must be strictly prevented and recovered.

 

[DAP]

What about having a dash camera that has neither a battery or a supercapacitor?

In an accident, the dash cam can lose power, either by the cars battery getting disconnected (or destroyed), or by the camera being knocked off its mount. The super capacitor provides sufficient power to complete writing the current video file. If that capacitor was not there, the camera would not be able to record the last file before the accident, and recording that file is the primary purpose of a dash cam. Without the capacitor, you would get a recording of hours of normal driving, but not the minute before and during the accident.
There is another problem that I don't think is fully addressed by dash cams yet. The force of the accident can knock the memory card out of the camera, or it can cause a momentary disconnection of the memory card from the camera (spring contacts can bounce away from the card given high enough g forces).

 

[qusejr2]

In an accident, the dash cam can lose power, either by the cars battery getting disconnected (or destroyed), or by the camera being knocked off its mount. The super capacitor provides sufficient power to complete writing the current video file. If that capacitor was not there, the camera would not be able to record the last file before the accident, and recording that file is the primary purpose of a dash cam. Without the capacitor, you would get a recording of hours of normal driving, but not the minute before and during the accident.
There is another problem that I don't think is fully addressed by dash cams yet. The force of the accident can knock the memory card out of the camera, or it can cause a momentary disconnection of the memory card from the camera (spring contacts can bounce away from the card given high enough g forces).

Yes , you are right . SD can be a problem in case big crash . with normal capactior and SD card workable status the last file can be saved even power supply is off . but without capacitor and power supply is off , we can save the last file but may lost last 3 seconds file.
Since supercapacitors have a limited capacity, they often fail to provide enough power to completely finalize and close the last file during a power interruption. While they supply sufficient power when the product is new, the capacity naturally degrades over time, making the power inadequate for saving the final file in most cases.

With recent dashcams adopting high-resolution 4K video while maintaining compact form factors, increasing the supercapacitor size is severely restricted. Furthermore, this capacity degradation over time remains an inherent, unsolvable issue. As a result, after about two years of use, most supercapacitors can no longer provide enough power to properly close the last file during a sudden power-off event.