Viofo A329T: Long-Term Review

[Chuck McCoy]

@TonyM
Thanks for the clarification, and additional testing.
This whole color banding issue is blowing my mind.
I guess why I've never seen it in my test footage is because I never enabled HDR in daytime testing.
But, now moving forward I will ONLY be using HDR both day & night in all my testing.

 

[rcg530]

@TonyM @rcg530

I’m so confused.

1.) Is this “Color Banding” problem caused by software, or hardware?
Software = HDR
Hardware = Lens

2.) A329S was released May 19, 2025, (almost 1 Year ago).
Why are we just now hearing about this Color Banding problem now?

3.) Why didn’t we have this “Color Banding” problem with A329 2CH (2024)?
A329 2CH (2024)
A329S 3CH (2025)
Both use same exact Rear Camera.

When I first encountered the issue in September 2025, I thought it must be a firmware issue. I reported it to VIOFO. Eventually in January 2026, the response from VIOFO was that issue mainly relates to the rear camera lens.

The A329 2CH rear camera, the A329S prototype units, and I believe the A329S early production units had the exact same rear camera. The next A329S production batch had the updated case design for the A329S RC420 rear camera, but I believe the electronics and lens are the same.

The RC420 has the image sensor rotated 180 degrees from the older unit. The physical plastic case is a slightly different size. The CPL filter that fits on the older unit is the CPL-500 and the CPL filter that fits the revised rear camera case size is the CPL-600. There are also vent holes in the RC420 that were not present in the older unit.

 

[Harsh]

@TonyM Visually which is the closest, when comparing Viofo's telephoto to the 6,8 and 12mm lenses we have used with the M1?

 

[TonyM]

@TonyM Visually which is the closest, when comparing Viofo's telephoto to the 6,8 and 12mm lenses we have used with the M1?

Without doing a side by side comparison, just from memory, I'd say 6-8mm is the closest.

 

[TonyM]

Back to my review...

Battery Discharge Testing - Low Bitrate Parking Mode

My car is a hybrid with a small 12V battery. My drive to/from work is about 10-15 minutes and I park at the office for 9 hours - not ideal for the long-term life of the car battery. I'm probably an ideal candidate for using a dedicated dashcam battery, however I wanted to test the A329T with my car battery first before taking that step.

Before the A329T, my primary dashcam was a 2CH A139 connected to an HK4 at 12.0V cut-off, and I noticed that the A139 frequently shut off during low bitrate mode (LBR) when parked at work. The A329T combined with the HK6 supports hybrid parking mode and I was interested to verify that this could extend parking coverage to the whole day.

Before testing the hybrid parking modes, I wanted to get a clearer picture of my car battery voltage throughout the day. The A329T can show the voltage reported by the HK6 in the OSD text, so I tried using this to monitor the battery over time. It was cumbersome to review hours of LBR video and enter the voltage values into Excel, but I did get some results that showed the voltage dropped to 12.0V around 7-12 hours, on a good day.

I soon found that using the HK6 was not a practical way to monitor the voltage over an entire day, and it was difficult to interpret the parking mode results without the context of seeing the periods of battery charge whilst driving. I spent a while trying to find a non-intrusive way to monitor the battery over time. Eventually I found what I was looking for in a battery-related discussion here on DCT: a BM200 bluetooth car battery monitor that logs the battery voltage every 2 minutes and saves the data for up to 70 days, with a companion app that can show real-time voltage with 1Hz refresh and an all-day voltage graph.

Here is a screenshot from the BM200 battery monitor, overlaid with my own annotations, showing 8.5 hours of low bitrate parking on a day where the resting voltage was high prior to commencing parking mode.
- I note that the battery voltage recovers by about 0.1V when the load is removed as the HK6 shuts off.
- I can also see that the voltage reported by the HK6 is slightly higher than the BM200. The voltage at cut-off according to the BM200 was 11.89V.

The following day I made the short drive to work then left the A329T in low bitrate parking mode. As shown in the graph below, the HK6 reached the 12.0V cut-off after only 2.5 hours. Later in the day I took another short drive, after which the battery dropped to 11.93V in just 2 hours of parking recording.

Summary
- For my car, the available recording time in low bitrate mode is highly dependent on the State of Charge (SoC) of the car battery. It may also be affected by the ambient temperature, something I did not log in these tests.
- The SoC is affected by durations of driving (charge), parking (discharge) and overnight (at rest), and presumably temperature as well
- If I keep the HK6 cut-off at 12.0V, I am unlikely to achieve 9 hours of low bitrate parking recording to cover a whole day at work
- I'm not particularly concerned if the BM200 and HK6 report slightly different voltages, provided that each device is consistent. I can adjust the HK6 cut-off up or down if I want a shorter or longer parking duration.

My next post will show the effect of using Hybrid Parking Mode on the A329T to extend parking coverage to a full day, and beyond...

 

[Chuck McCoy]

available recording time in low bitrate mode

Very nice testing using BM200 Battery Monitor.
Can you hook up a 20 Watt Solar Panel to check if that will maintain vehicle starter battery voltage above 12.0V so you can have LBR Parking Mode for the whole day at work?

 

[TonyM]

Very nice testing using BM200 Battery Monitor.

Apparently it only consumes 1.5mA by itself, so not a big parasitic draw but perhaps not something I'd want to keep installed permanently.

Can you hook up a 20 Watt Solar Panel to check if that will maintain vehicle starter battery voltage above 12.0V so you can have LBR Parking Mode for the whole day at work?

Can that solar panel charge the battery via the OBD port? Interesting...
I'm not sure I get enough sunlight for that in the UK! However, it's an interesting idea.

 

[Chuck McCoy]

- I can also see that the voltage reported by the HK6 is slightly high. The actual voltage at cut-off according to the BM200 was 11.89V.

How do you know HK6 is reporting “high” and BM200 is not reporting “low”?
Do you have a FLUKE to check accuracy of BM200?

Can that solar panel charge the battery via the OBD port? Interesting...

I want to buy that thing to test it out, especially the OBD2 charging adapter.
But, I don't have the disposable income.

 

[TonyM]

How do you know HK6 is reporting “high” and BM200 is not reporting “low”?
Do you have a FLUKE to check accuracy of BM200?

We've had this discussion elsewhere on DCT before. I'm not really bothered whether the HK6 reads slightly high or low, so long as it is consistent in what it does. If I want the HK6 to cut-off earlier I'll set it to 12.2V, if I prefer later I'll set it to 11.8V which is what I have at the moment. Using the BM200, I can see that the battery voltages vary by much more than whatever the tolerance is within the HK6, so I'm not concerned about it.

I updated my post above to say that as an observation from looking at the graph, the voltage reported by the HK6 is slightly higher than the BM200, and in the summary I added a note that I'm not concerned if they read slightly different voltages, provided each device remains consistent.

 

[Velvetfoot]

In my view, it's nice to know the HK6 actually does cut off to protect the battery.
No hardwired dashcam, but I've been monitoring my '26 Prius (small) 12V battery voltage using something similar.
During winter it was charging at 14.3 v, now it's at 12.7. This can be defeated, but I haven't.
Five hours after engine shutdown, the fuel vapor pump comes on-noticable hit.
I was working on the car for a while yesterday-real noticeable hit.
Morale of the story for me: It doesn't take much to draw the battery down.

edit: I don't know if it would be practical/possible/advisable to keep the hybrid system on Ready, with no heat/A/C. If the SOC of the traction battery was high to start, the 12V battery should be charged by the DC/DC converter. In effect, a giant dashcam battery. Of course, the engine could start, lol.

 

[TonyM]

In my view, it's nice to know the HK6 actually does cut off to protect the battery.
No hardwired dashcam, but I've been monitoring my '26 Prius (small) 12V battery voltage using something similar.

My '21 Corolla battery is possibly similar to your '26 Prius.

I was working on the car for a while yesterday-real noticeable hit.
Morale of the story for me: It doesn't take much to draw the battery down.

Leaving the car doors open for a while does draw down the battery quite a lot. My battery went 'flat' the first time I left the ACC circuit turned on whilst installing a dashcam in the Corolla.

If we take a while getting the family & dog out of the car after arriving at a destination, the HK6 can cut-off parking mode before we have even left the car!

If I know we're going to remain in the car for a while I now leave the ignition ON whilst parked to ensure the 12V battery remains topped up in the Ready position.

 

[TonyM]

Battery Discharge Testing - Hybrid Parking Mode

In post #25 above I showed that the small 12V battery in my car is not ideal for powering the A329T in Low Bitrate parking mode for 9 hours whilst I am at work. One option for me is to purchase a dedicated dashcam battery. A lower-cost alternative is to purchase a HK6 hardwire kit and use Hybrid Parking mode in the A329T.

Hybrid parking mode allows the user to set 2No cut-off voltages, one in-camera and typically a lower voltage in the HK6. When the power supply voltage drops to the cut-off selected in-camera, the dashcam switches from the selected mode into Low Power Impact Detection (LPID). In the example below I set the in-camera cut-off to "12.0V", and set the parking mode to "Low Bitrate -> Impact". The HK6 was set to 11.8V.

Using the BM200 battery monitor we can see how this hybrid parking mode works:
- My car battery was resting at about 12.2V overnight.
- 20min drive to school & work at 8am
- 4.5 hours of Low Bitrate parking recording until the in-camera voltage trigger at 12.0V
- The A329T then enters Low Power Impact Detection parking mode
- The car battery recovers to higher than 12.0V when continuous recording stops
- I tapped the windshield at 14:35 to simulate an impact - the video recording causes a short duration voltage drop

In addition to the full-day graph, the BM200 can display the real-time voltage with 1Hz refresh. I enabled this before the test impact:
- LPID enabled, battery at ~12.1V
- Simulated impact at 14:35:20, battery drops to ~12.0V
- A329T wakes up, records a 30 second event video, then resumes LPID
- Battery returns to ~12.1V

Summary
- Hybrid Parking mode on the A329T allows me to combine continuous parking recording with low-power impact detection
-> I can have low bitrate recording for all short-duration parking situations such as shopping trips
-> I can also have impact detection coverage for longer duration parking at work

 

[Velvetfoot]

LPID very efficient, for sure. Impressive.