Buying a new phone on Black Friday can seem like the best idea, yet sometimes, it can be an expensive mistake. The American tradition has traveled all the way to Europe to become one of the most expected days of the year to renew your devices. The smartphone market in Spain is one of the most active in Europe: brands like OPPO, realme, Xiaomi, Samsung and Apple fight to get your attention with offers, “bargain” posters and data sheets full of numbers.
However, reviews in media like El Androide Libre or GSMArena warn that it is easy to get lost.
So that you don’t regret it in a few months, here are the three most important mistakes when changing phones and how to avoid them before swiping the card on Black Friday 2025 according to the experts.
Error 1: buying less internal storage
The first big mistake is to think that “with 128 GB I have plenty.” Today (in most cases), it’s actually the other way around.
Only by getting your new phone (Android o iOS) out of the box and turning it on—system, pre-installed apps, bloatware and internal files starting space—and between 15 y 30 GB are gone. And just like that, part of the space disappears before even installing your first app.
Then come the apps that we use at all hours:
- WhatsApp storage photos, videos, audios, documents and years of chats. A backup can easily exceed 10 or 15 GB.
- Social networks like Instagram or TikTok download and cache hundreds of photos and videos so that the “feed” loads instantly. But that cache can take up several GB per app.
- Streaming platforms like Netflix or Spotify fill the mobile when you download series, movies or playlists to watch and listen to them offline.
Then, you still have to add your own photos and videos. With high resolution or RAW can be a lot of MB. Videos in 4K at 60 fps can take between 400 and 500 MB per minute.
Google Photos, iCloud and others need a good connexion to internet to upload the content, and that also store cache on the phone.
Error 2: stop getting fooled by the camera
“The more megapixels, the better camera.” According to the experts, this is the biggest and more commum mistake. A megapixel only measures the resolution (size of the picture), no the quality of it.
What really matters is:
- The size of the sensor: a larger one captures more light, more detail and less noise, especially at night. A large 12 Mpx sensor can give better results than a tiny 108 Mpx sensor.
- The aperture (f/1.8, f/2.0…): the lower the number, the more light enters. This is key for night photos and portraits.
- Image processing: the software that transforms what the sensor sees into the final photo.
Some phones use “pixel binning”: group pixels that end up delivering photos of, for example, 12 Mpx, even if they sell “108 Mpx” in the box. In the mid-range, a module with four lenses usually have: a decent main one, an acceptable wide angle… and then a 2 Mpx macro and a depth sensor that provide almost nothing. Two good cameras are much better than four bad ones.
The front camera: used mostly for WhatsApp video calls, Instagram stories or videos for TikTok, should also have a good resolution, and autofocus.
Error 3: look only at the mAh of the battery
Buying an Android with less than 4,000 mAh in 2025 (unless it is a “mini” or foldable model) is to risk living stuck to the plug. iPhones have a great optimization, they can hold the same or more than an Android with more mAh.
Check the fast charge: today is posible to recover 50% battery in about 15 minutes and 100% in less than 40.
Finally: is your charger adapted? Samsung have the “Super Fast Charging”, OPPO the “VOOC”, Xiaomi the “Hypercharge”… If yours doesn’t bring one, you usually need between 45 W or 65 W (the old ones are on average 15w).