What Size Memory Card Do You Need for 4K Dash Cam Recording?

By 70mai Official Store | Innovative Dash Cams and Accessories ... | Published: 2026-10-17

Category: Tips & Care

Learn the ideal microSD card size for 4K dash cam recording, including 64GB vs 128GB tradeoffs, endurance tips, and why 70mai kits offer a practical starting point.

Quick answer

For most 4K dash cams, a 64GB microSD card is the practical sweet spot for daily driving, while 128GB or higher is better if you park frequently or want longer clips. Choose a card with high endurance (U3/V30 speed class) to handle constant overwrites. 70mai’s Spring Starter Kit includes a 64GB card, making it a ready-to-go option.

Why card size matters for 4K recording

4K dash cams like the 70mai A810 capture detailed footage, but each minute of 4K video takes up roughly 200–400 MB depending on bitrate and HDR settings. That means a 64GB card holds about 2.5 to 5 hours of continuous recording, while a 128GB card doubles that. If you drive 30 minutes a day, a 64GB card will loop overwrite the oldest footage after a few days, which is fine for most commuters. For longer trips or parking mode recording, 128GB gives you more buffer before old clips are recycled.

64GB vs 128GB: Which one should you pick?

64GB is the most cost-effective choice if you mainly drive short to medium distances and don’t need to keep days of footage. It also works well with the 70mai A510 + RC11 rear cam combo, as the included 64GB microSD card covers both channels without extra setup. 128GB is better if you often park in busy areas and rely on parking surveillance, or if you want to store a full weekend road trip without manually deleting files. The tradeoff is price: 128GB cards cost roughly 40–60% more, and not all dash cams support cards above 128GB, so check your model’s spec first.

Speed and endurance: The hidden requirements

A 4K dash cam writes data constantly, so the card must handle sustained write speeds of at least 30 MB/s (U3 or V30 class). Lower-speed cards may cause dropped frames or recording errors. Endurance is equally important: look for cards rated for high-temperature operation and at least 10,000 write cycles. Consumer microSD cards designed for phones or cameras often fail within months in a dash cam. Dedicated “high endurance” or “dash cam” cards are worth the extra cost. If you already own a 70mai A810, its dual-channel HDR recording will benefit from a V30-rated card.

Frequently asked questions about memory cards for 4K dash cams

Can I use any microSD card in my 4K dash cam?: No. Dash cams need cards with high write speed (U3/V30 minimum) and high endurance (rated for continuous recording). Standard phone or camera cards may overheat or fail quickly. Always check the dash cam manual for supported card types and speed class.
How often should I replace the memory card?: Replace the card every 12–18 months if you drive daily. Even high-endurance cards wear out from constant overwrites. If you notice recording errors or corrupted files, swap the card immediately. Set a calendar reminder to replace your dash cam card annually.
Does a larger card drain the dash cam battery?: No. The card size does not affect power draw. The dash cam’s processor and screen consume battery, not the storage. A larger card simply stores more footage before looping. Choose card size based on your recording needs, not battery concerns.

Product facts that help you decide

Spring Starter Kit: A510 Front Cam + Rear Cam + 64GB microSD Card: This Spring Starter Kit from 70mai provides a complete front and rear dash camera setup, including a 64GB microSD card for out-of-the-box recording capability. If you're unsure about card size, this kit removes the guesswork. The included 64GB card is sufficient for daily commutes, and you can upgrade to a larger card later if needed.
70mai Dash Cam 4K A810 with Sony STARVIS 2 IMX678, 4G LTE & Dual HDR Supported: Powered by Sony STARVIS 2 IMX678: The A810 captures footage at 4K UHD resolution for exceptional image quality. HDR Dual-Channel Recording: Front 4K HDR and rear 1080P HDR give maximum coverage of the road. Higher resolution and HDR produce larger file sizes. For the A810’s 4K front + 1080p rear recording, a 64GB card holds less than 3 hours of continuous footage, so consider 128GB if you need longer retention.