Zenfox U1 2-Channel Dashcam Review

rcg530

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Several weeks ago I started a review of the Zenfox U1 2-channel dashcam. I'm quite impressed with the overall video quality from both cameras.

Parking Mode Questions

The U1 user manual does not clearly define the parking mode operation when powered by the 12-volt power port adapter (motion based parking mode). I was getting somewhat inconsistent behavior with the motion based parking mode. It would sometimes start parking mode after 10 minutes of being motionless, on rare occasions it would start after 5 minutes of being motionless and other times it would not go into parking mode at all. It still continued recording in normal mode if it did not go into parking mode.

When I obtained the Zenfox hardwiring adapter, parking mode worked well at that point.

I'm still waiting on Zenfox support to supply me with a definition of what it should be doing in motion based parking mode.

Dropped Video Footage At File Transitions

I've been comparing the Zenfox U1 rear video footage with another vendor's rear video camera footage because the other vendor's camera is generating very dark video footage. These ongoing comparisons of video footage had me looking a lot at the video files generated by the Zenfox U1 cameras.

The Zenfox U1 has a 1-minute file rotation time period. I found more than a few examples where I would find the rear dashcam's video footage would be listed at 59 seconds in length. The filenames of the video files also had a longer than one minute gap (front and rear video files). It appears that the video file storage process is getting delayed in storing the video content by 3 to 5 seconds when this occurs. When that delay occurs, there are 3 to 5 seconds of video footage being lost.

In the following examples, you can see that when it's working correctly, the filenames have a 60 second gap (maybe even 61 seconds at rare times). When the problem occurs the filename time gap is 63 to 65 seconds.

I've reported this issue to Zenfox several weeks ago and they are investigating the issue and looking for a fix.

zenfox_u1_missing_seconds_examples.jpg

Review Status

I've paused my review of the Zenfox U1 2-channel dashcam for now. When Zenfox support provides the additional information and fix for the dropped video frames, I'll resume the review.
 
While I'm waiting on Zenfox support to get back to me on this issue (several weeks now), I ran some tests the past couple of days.

I've removed the Zenfox U1 2-channel dashcam from my car. I ran some tests in my filming studio with both front and rear cameras pointed at my iPad with a digital clock on the screen (showing down to the second) to see if I could capture the 3 to 5 second gap in the videos during a file transition. I've run this test twice (first time for 1 hour two days ago and the second time for 90 minutes today). I did not find any odd file transitions during these test conditions.

Either my U1 front camera has a defect or having the cameras installed in my car and exposed to vehicle movement and the sun are causing the triggering conditions for the problem.
 
I've now tested three different microSD cards in the Zenfox U1 2-channel dashcam and when sitting on my desk in my filming studio, the Zenfox U1 2-channel dashcam can run 10 hours with no frame loss issues occurring. I've tested with the Zenfox hardwiring power adapter and the USB power adapter power the U1 both in my filming studio and in my car.

I reinstalled the Zenfox U1 in my car this past week. Any time I drive my car, there will be one to three occurrences of the frame loss at a file transition problem.

I'm trying to get Zenfox support to recommend a specific microSD card to use with the U1 to eliminate that from the conversation once and for all.

I've tested the following microSD cards in the Zenfox U1 2-channel dashcam
  • SanDisk 256 GB High Endurance C10, U3, V30
  • VIOFO 128 GB MLC, U3, V30
  • SanDisk Extreme Pro 256 GB UHS-I U3 A2 V30
I use the h2testw program to verify all of the file system storage in each microSD card before I put it into a dashcam. I use the "FAT32 Format" for Windows to format the card with a FAT32 file system as stated in the Zenfox U1 user manual. I then use the Zenfox app to use the format option within the app to format the microSD card before attempting to use it with the Zenfox U1.

I hope to get a specific recommendation from Zenfox support for a microSD card to use, so we can finally move on to what looks either a defective U1 dashcam or a bug in the Zenfox U1 firmware.
 
Could it be a bump or jolt during the drive as the file is being recorded? I guess you could bench test that by jarring the cam slightly while filming the clock. Other possibility might be voltage variance @12V which might happen in a car but likely wouldn't on a mains-powered in-house test set-up.

Phil
 
Could it be a bump or jolt during the drive as the file is being recorded? I guess you could bench test that by jarring the cam slightly while filming the clock. Other possibility might be voltage variance @12V which might happen in a car but likely wouldn't on a mains-powered in-house test set-up.

Phil
I've had the problem occur while the car was traveling through a parking lot at less then 3 mph with no bumps being encountered, while driving at 40 mph down a somewhat bumpy road and while traveling at 55 mph while driving down a recently paved smooth section of road.

I've had the Zenfox U1 installed in my car two different times. The first installation had it being powered by the Zenfox hardwiring kit (3-wire) and it was getting its power from a Cellink B dashcam battery pack. The second installation of the U1 has it getting its power from the USB power adapter supplied with the dashcam and the 12-volt power for the USB power adapter is coming from a BlackVue B-112 dashcam battery pack. The problem has occurred with both power source configurations.

I just received a request from Zenfox support to try running the U1 with the rear camera disconnected to see if the problem occurs again.
 
My first 30 minute drive with the Zenfox U1 rear camera disconnected resulted in no lost frame events. On Friday, I'll go on a 90 minute drive with the rear camera disconnected to see if any problems occur.
 
I went on my weekly shopping trip. During this test, I left the Zenfox U1 rear dashcam disconnected.

There were zero occurrences of the normal mode file transition problem. It looks like that issue only occurs when the rear camera is connected. I've reported my findings to Zenfox support.
 
While I've been testing two other dashcams, I've continued my investigation into the Zenfox U1 2-channel dashcam losing video frames at select file transitions.

I've detected some "patterns" to the behavior.

I'll label the video file that is before the file transition with missing video is "File 1" and the video file that is after the file transition with missing video is "File 2".

There are three locations along my video test route where the loss of video frames takes place in the front and rear video files.

I used "Dashcam Viewer" to extract the data from video files.
  • Only during daylight hours
  • Only when both the Zenfox U1 front and rear cameras are operating
  • When there are road side objects/trees that block the sunlight shining on the car in a quick successive pattern.
  • There are utility power lines on the side of the roads in this area and in same areas power lines do cross the road
  • The internal timestamp, GPS LAT/LNG and Bearing(Deg)
    • There are 60 entries for the one minute file
    • There are numerous entries with repeated timestamp and GPS data values
    • The are sometimes multi second gaps of missing data (may be related to the repeated timestamp/gps data entries)
    • Some timestamp/GPS data entries are missing from "File 1"
      • Those missing timestamp/GPS data entries from "File 1" end up appearing in "File 2" (based on timestamp value)
    • Some timestamp/GPS data entries present in "File 2" have entries in "File 1" with the exact same timestamp, but with slightly different GPS data.
    • In one case, "File 2"'s first 14 timestamp/GPS entries had timestamp values that were before the Real Time Clock (RTC) overlay text at the end of "File 1"
If I drive the same route at night, no lost video frames occur and the timestamp/GPS data, as presented by the Dashcam Viewer program, looks appropriate (unique timestamp values for each line of data in the file).

I've reported my findings to Zenfox support.
 
I've continued to test this problem by testing a wide variety of microSD cards suggested by Zenfox. None of the suggested microSD cards changed the problem behavior.

A couple of days ago, I received a test firmware release for the Zenfox U1. I was pleasantly surprised to see no loss of video and no missing video files during my short test drive. The loss of video during file transitions problem only seemed to occur during bright/sunny days (see previous post) and my first test drive was on a bright/sunny day. The rest of the week will be cloudy/rainy, so it may not be the best test of the new firmware.
 
Well about bloody time then :)

It is funny how cameras can behave some times, either out of the blue or some deep down thing in the firmware like say issues if you get beyond 24 hours of parking guard,,,,, which i think few people do and so not something that pop right up during testing.
Hope your zenfox U1 boat will give you smoother sailing going forward.
 
Zenfox U1 Config:
  • Firmware
    • Front: Zenfox U1.V1.2.20220414
    • Rear: V1.0_20210701
  • Video
    • Bitrate Setting = High
    • Resolution = 4K 30fps + 1080P 30fps
  • Parking Mode = Low Bitrate Recording
  • Power Setup
    • Cellink B dash cam battery (3-wire connection)
    • Zenfox U1 Hardwire Kit
The recent Zenfox U1 firmware update appears to have resolved the problem of the multiple seconds of video/audio loss at file transitions (in select locations involving extreme brightness transitions).

Yesterday, I went on a long drive with my car to a car club gathering where the car would be parked for several hours. I wanted to see if another problem I've observed with longer parking mode sessions would occur or not. The problem being that parking mode starts off just fine (both channels have video recorded) then about 90 minutes to 2 hours into parking mode the rear video channel stops getting video recorded.

Here are the last few normal mode files from the Zenfox U1 as I arrived at the car club event and parked. In fact, these are the last normal mode video files for the entire trip.
zenfox_u1_20220514_normal_mode.png

Here are the first few sets of parking mode files.
zenfox_u1_20220514_pm0.png

This file listing is when the rear channel stopped getting video files recorded for it.
zenfox_u1_20220514_pm1.png

The outside temp was 64 F/17 C when I parked the vehicle (after about 2 hours of the U1 recording in normal mode) and by the time I left the event the outside temp was 81 F/27 C.

The front video channel gets video recorded for however long the parking mode remains active. When I start the car and the U1 attempts to transition back to normal mode, the upper left red LED is blinking and it stops recording video for the entire remainder of the car trip.

This is a file listing showing the files at the tail end of the parking mode session. The 34 second video is the last one in parking mode and it should have transitioned to normal mode recording.

zenfox_u1_20220514_pm2.png

On the route home I had two short parking mode sessions and the U1 didn't record anything in normal or parking mode the entire trip home.

I'm removing the Zenfox U1 from my car since I need to make room for a couple of other dash cams that I'm reviewing right now. I'll try an extended parking mode test in my filming study to see if this is just time related or heat related.
 
The never ending dash camera review continues....

A few weeks ago, I was given access to a V1.3_0701 firmware update for the front and rear Zenfox U1 dash cameras. I ran some preliminary tests in my filming studio and the results looked promising.

This week, I removed a couple of dash cameras from my car to make room for the Zenfox U1 2-Channel (again). Today, I drove my car on my weekly shopping trip route and the results were not good for the Zenfox U1. The outside temp was 83F/28.3C and the inside air temp was around 95F/35C. The U1’s temps were 127F/52.7C on both lower corners and 140F/60C on both upper corners. During this last parking mode session, the U1 front camera was not exposed to direct sunlight but the rear camera was exposed to direct sunlight.

During the third/last parking mode (low bitrate), the U1 lasted about 18 minutes before the rear camera recording started to drop off. This time the U1 would reboot, start a less than one second normal mode file before going back into low bitrate parking mode where it would fail again and reboot again. Eventually, the rear camera video stopped recording and that's when alert beeps could be heard (in the audio of the other dash camera video being recorded at the same time).

When I reinstalled the Zenfox U1, I reformatted the microSD in the dash camera (FAT32 - 64K allocation unit size). After capturing all of the diagnostic info, I reformatted the microSD card again and ran a h2testw check and no errors were found. I was using a Kingston CANVAS Select Plus 128 GB microSD as this was the microSD I was told to use by Zenfox and it was the "most compatible" with the Zenfox U1 strange behavior I first encountered last year when this review started (October 2021).

IMO, either there are still some bugs in the (front and rear) camera firmware or I have a defective unit. I've reported my findings to Zenfox.
 
One year ago, I received the Zenfox U1 2-channel dash camera to review. I've spent a large number of hours (weeks) testing this dash camera. The initial problem of it not writing all of the video around the file transition points took a very long time to get Zenfox to resolve. I had hoped that the U1 would then prove to be a decent budget friendly 4K UHD front / 1080p rear dash camera.

I've tried numerous rear camera firmware updates to try and resolve the rear channel video recording going offline and eventually the front camera won't transition from low bitrate parking mode back to normal mode recording.

I'm pulling the plug on this review. This is the first dash camera I've reviewed that I have to say "do not buy".
 
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