Does a Modern Dash Cam Still Need a Supercapacitor?

For years, supercapacitors have been used in dash cams for one important reason:

When the power suddenly disappears, the camera needs enough time to finish saving the video it is recording.

But that solution was designed around the way video files were traditionally written.

Modern recording technology gives us another option.

The Problem With Traditional MP4 Recording

A conventional MP4 file normally depends on important indexing information that is finalized when the recording is properly closed.

If power is removed before that process finishes, the video data may already be on the memory card, but the file itself may not open normally.

That is why older dash cams benefited from a battery or supercapacitor.

A few extra seconds of power gave the camera time to finish the file.

Some Cameras Use TS Recording Instead

Another approach is MPEG-TS recording.

TS is naturally more tolerant of interrupted recording than traditional MP4 because it does not depend on one final file index in the same way.

That can reduce the chance of losing an entire recording when power is suddenly removed.

But it does not automatically mean every frame immediately before the power loss has already reached the memory card.

Depending on buffering and implementation, the final moments before shutdown can still be lost.

Pelsee took a different approach.

Pelsee Uses Fragmented MP4 Recording

In our current recording architecture, Pelsee uses an optimized form of fragmented MP4, or fMP4.

Instead of waiting until the end of the recording to build one complete index, the video is written progressively in smaller fragments.

Each completed fragment already contains the information needed for playback.

So if external power disappears suddenly, the recording does not depend on the camera staying alive long enough to finalize the entire file.

In our implementation, video recorded up to the interruption remains playable.

That is the key difference.

Why This Changes the Role of the Supercapacitor

We tested what happens when power is removed while the dash cam is actively recording.

With our fragmented recording architecture, the last file remains playable through the point where power is interrupted.

We also require validation that repeated unexpected shutdowns do not damage the microSD file system or cause abnormal card behavior.

Once those two problems are addressed, keeping the entire camera running for another one or two seconds provides very little additional benefit.

And on a modern high-resolution dash cam, keeping the full system alive requires more energy than many people realize.

The processor, DDR memory, image sensor and microSD card all remain active.

A larger supercapacitor could keep them running slightly longer—but if those extra seconds are not required to preserve the recording, adding more stored energy does not necessarily improve the final result.

We Prefer to Test the Outcome

This is why we do not treat the presence of a supercapacitor as a simple measure of dash cam quality.

For us, the more important questions are:

Does the recording remain playable if power disappears?

Is the footage immediately before the interruption preserved?

Does the microSD card remain healthy?

Does the camera restart normally afterward?

Our power-loss testing is built around those results.

Does This Mean Supercapacitors Are Bad?

Not at all.

A supercapacitor remains a perfectly valid way to provide short-term backup energy, and many well-designed dash cams use one.

What has changed is that it is no longer the only way to solve the original problem.

Modern storage formats, firmware and power-management design give engineers more options.

Pelsee's approach is to solve the problem at the recording and storage level rather than rely on a few additional seconds of backup power.

Because in the end, the component inside the camera is not what matters most.

What matters is whether the footage you need is still there when the power goes out.