70mai A800S Review: Best Low-Cost 4K Dash Cam

70mai A800S dual dash cam

Technical Specifications

– Dual channel dash cam
– Released 2021
– Max. resolution: front 4K (2160p), rear 1080p
– Price: Amazon US / CAAliExpressmore countries & vendors (affiliate links)
– Wi-Fi (2.4 and 5GHz)
– 3″ Screen
– Video format: MP4
– Codec: H.264 or H.265
– Supports up to 256 GB MicroSD cards
– Sigmastar SSC8629G processor
– Time and date stamp on video
– Loop recording, auto on/off, G-Sensor
– Parking modes: Non-buffered
– Lock file button
– CPL filter available separately
– Operating temperature: from -10°C to 60°C (14°F to 140°F)
– Apps for Android / iOS
– 500 mAh battery
– Internal microphone and speaker
– Adhesive mount

Front Camera:
– Max. resolution: 3840×2160 @ 30fps
– Bit rate: 25 Mbps
– Aperture: f/1.8
– Size: 89mm x 60mm x 36mm
– Sony STARVIS IMX415 CMOS sensor
– Angle of view: 140° diagonal

Rear camera:
– Designation: RC06
– Max. resolution: 1920×1080 @ 30fps
– Bit rate: 8 Mbps
– Aperture: f/2.0
– Galaxycore GC2053 sensor
– Angle of view: 130° diagonal

70mai A800S Review

70mai is the “dash cam branch” of the well known Chinese tech company, Xiaomi. You might know them for their phones.

Their dash cams are fairly reliable for the price. The A800S is a low-cost true 4K dash cam with an optional rear camera (although on Amazon, the A800S is currently only available in its dual-channel version). The rear camera is called RC06 and records 1080p video.

Most dash cams below $200 that claim to record at 4K resolution resort to tricks like interpolation. Check out this article if you would like to know more about fake 4K dash cams.


With its black wedge shape and small size, the 70mai A800S is so discreet that it’s barely visible from outside the car. The camera sticks to the windshield with an electrostatic sticker, which leaves no residue on the glass when you remove it.

The A800S has a 3″ screen on its rear side, making it easy to operate the camera and review videos.

Alternatively, you can operate it via Wi-Fi from your smart phone. As usual, apps are available for Android and iOS. Unlike many the apps of many other dash cams, 70mai’s app is well-designed and relatively straightforward to use.

Video Quality

The 70mai A800S records true 4K video with its forward camera, meaning 3840×2160 pixels at 30fps (frames per second). The rear camera records 1080p (1920×1080 pixels), also at 30fps.

Video quality of the front camera is very good during the day, and fair at night. That’s quite impressive for a dash cam of this size.

The video feed of the rear camera leaves a bit to be desired, though: It records only fair video during the day, and mediocre video at night. Especially at night, you will only be able to read license plates of other cars when they get very close (such as, at a red traffic light).

Basic Parking Mode

When installed with its corresponding hard-wiring kit (~$15), the A800S supports a simple (impact-triggered, non-buffered) parking mode.

Simple parking mode works like this: If the G-sensor of the dash cam records an impact while the car is parked, the camera will come alive and record a video.

The problem with this kind of parking mode that in the time it takes the dash cam to wake up and start recording, the perpetrator might already be gone.

User Manual

The user manual for the 70mai A800S comes in 8 languages, but at only 11 pages for the English version, it only explains the basics. It does point you to an online guide though which goes into more detail.

Other Observations

This camera comes with an internal Li-ion battery, which is a negative. Most modern dash cams have capacitors. Batteries are less heat resistant than capacitors and can cause problems when the interior of the car becomes too hot. If you live in a hot climate, you’re better off getting a capacitor-based dash cam.

A CPL filter is available separately for around $10.


70mai’s A800S is a must buy if you’re looking for a true 4K dash cam but don’t want to spend hundreds of dollars on it.

The forward camera records good quality video overall, and the device is fairly reliable. Don’t expect any miracles from the rear camera though, its performance is just slightly better than mediocre.

The only other true 4K dash cam we know of in this price range is the Blueskysea B4K, which has unfortunately gone out of production and is nowadays only available on eBay.


  • Reliable
  • Easy to set up and use
  • Great price for a true 4K dash cam
  • Simple parking mode


  • Internal battery instead of capacitor

70mai A800S Video Samples

For full original video quality, make sure to watch on full screen and select maximum video resolution (use the cog icon in lower right corner). You may have to rewind the video after changing the resolution.

Day Time Front Video Sample

Forward video quality during the day is very good. It is easy to read license plates of other cars even when driving by.

Day Time Rear Video Sample

Rear video during the day is fair. It’s not super sharp, but you can clearly see everything and you can even read license plates when they are close enough.

Night Time Front Video Sample

Forward video during the night is fair. Again, you can only read plates when the other car is quite close.

Night Time Rear Video Sample

Rear video at night is mediocre. The glare from other cars’ headlights is extreme. However, at 0:35 in the video, we are able to read at least one license plate from up close, so it’s not all bad.

Compare Prices And Buy Online Today

The 70mai A800S is available for sale from the following vendors:

70mai Store

Amazon US / CA

eBay US / AU

AliExpress (global)

Links to vendors are affiliate links, and help to support this site.