70mai A900 and A900 Ultra review: dual 4K dash cams compared

A dash cam is one of those purchases you hope will spend its entire life recording nothing particularly interesting. But if something does happen, you want more than a blurry suggestion that a car was involved.

And you would quite reasonably like the camera looking out of the back window to be as useful as the one at the front. That's the appeal of two new launches from dashcam specialists 70mai.

It's the new A900 series, made up of the A900 and the flagship A900 Ultra, which are both available to pre-order now from the 70mai website.

They each offer proper 4K recording from front and rear cameras, HDR recording, and support for connected features through optional 4G equipment.

The Ultra goes further with Sony STARVIS 2 sensors at both ends, upgraded image processing and more sophisticated parking surveillance.

What I liked about the 70mai A900 and A900 Ultra

The most appealing feature is the equal attention given to what happens behind you. A rear camera can help explain a collision, capture the behaviour of a following driver, or provide another angle on an incident. Giving it proper 4K resolution makes a lot of sense, and it's commendable to see a dashcam that offers this.

The standard A900 records at up to 30 frames per second from both cameras and supports HDR at the front and rear. HDR helps balance bright and dark areas, which matters when headlights, shadows and changing daylight are all competing within the same picture.

There is also scheduled HDR activation. I like having the option to let the camera change its behaviour at set times, rather than expecting the driver to keep adjusting it.

The Ultra’s main imaging upgrade is its pair of Sony STARVIS 2 IMX678 sensors, supported by 70mai’s Night Owl Vision system and trick colour processing.

I also like that the standard A900 hasn’t been stripped of useful features to make the Ultra look better. It has built-in GPS, a 3.18-inch screen, voice control and Wi-Fi 6 for transferring recordings to a phone. It's also the slimmer of the two front units, but both cameras support microSD cards up to 512GB.

The Ultra has a clever parking surveillance system that adds AI motion detection and more advanced collision monitoring, alongside low-power operation designed to reduce the energy needed while waiting for an event. there's even an add-on battery pack available to make this system even more functional. The optional Battery Pack Mini adds a separate power supply for parking surveillance. This isn't something I've come across from a dashcam before, so it's another great innovation from 70mai.

There's even optional 4G connectivity. With the appropriate kit, service and configuration, remote access lets you check recordings and monitor the car through the app without standing beside it.

What I didn’t like about the 70mai A900 and A900 Ultra

The first complication is working out what your chosen package actually includes. Parking surveillance needs a suitable permanent-power arrangement. Remote connectivity requires the compatible 4G hardware and mobile service, while some cloud functions involve a paid plan. The Battery Pack Mini is another separate purchase.

It is easy to read the complete feature list and picture everything working straight out of the box. In practice, you need to price the setup you want, including any installation, rather than judging either camera on its headline cost alone.

Installation is also more involved than fitting a single front camera. You have a cable to route to the rear window, and a neat result takes planning. Hardwiring introduces another job, so professional fitting may be worthwhile if you aren’t comfortable with vehicle electrics.

The Ultra’s front unit is chunkier, too. Its screen and hardware have to go somewhere, but I would check the available space around the mirror before deciding where to mount it.

There are limitations to the standard A900’s parking protection.

It offers collision detection and time-lapse recording, but lacks the Ultra’s AI motion detection. It's one of a few basic compromises, but worth noting.

Overall verdict - should you buy the 70mai A900 or A900 Ultra?

The A900 makes a strong case for being the sensible starting point. It offers the feature that matters most here, 4K recording in both directions, alongside HDR, GPS and convenient access to footage.

If your priority is recording journeys and having useful evidence if something happens, I wouldn’t automatically assume you need the Ultra.

The flagship earns its place through its upgraded imaging hardware and more ambitious parking protection.

Those extras make more sense if you regularly drive after dark, leave your car in places where you want additional monitoring, or intend to build a connected setup with the appropriate accessories.

My inclination would be to choose the A900 for straightforward front-and-rear recording, and the Ultra for a more comprehensive surveillance system.

But I would compare the complete package prices before deciding. A camera, rear unit, memory card, power kit and connected service can become a rather different purchase from the tempting starting figure.

Both models take rear recording seriously. The important decision is whether you want your dash cam mainly watching the road, or doing a more sophisticated job when you’ve walked away.