The best you can get. (It has only one issue that you will see below)

I usually use it by wirelessly sending images from my phone, but in the past I have also used it from Windows, via USB-A to USB-C if I remember correctly. There is the possibility to print directly from an SD card, from the printer's menu and buttons, but I have never tried it.

When sending photos from a mobile phone, you need to have the WiFi on the phone turned on for them to communicate (I think the GPS too). The printer creates a WiFi Access Point (a.k.a Hotspot) to which the phone connects for a few seconds to send the photo (no internet connection is needed).
For the phone, there is an application called "SELPHY Photo Layout", through which you can select which photos you want to print (you can print multiple on the same paper). However, you can also, when viewing a photo in the "Gallery" of the phone, press Share and select the Selphy application to print it a little faster.
Each photo takes a few seconds to come out because it goes in and out 4 times. As it prints, the paper moves back and behind the printer, so it needs a little space behind. So, you cannot stick the printer all the way back to the wall.

The photo papers I use are "Canon RP-108" and they work perfectly. They contain 2 ink cartridges and 108 papers. That means each ink cartridge corresponds exactly to 54 papers.
If you go to use the device after a long time, blow a little on the first paper so that it doesn't have any dust because if the printer takes the paper with a little dust on it, that dust will be permanently in the photo and will appear as spots.

The only problem I found with the printer is that sometimes, in some photos, a very faint and thin vertical line is visible (with difficulty). This line, when it exists, always appears in the same spot, regardless of the papers and ink. I have tried everything and it has to do with the printer. From what I later searched, this is a characteristic of the entire Selphy series, not just the CP1500 model. Before I searched for this problem, I took the printer back to the store where I bought it because I thought it was something unique to mine. The person there couldn't even see the line with his eyes, I had to take a photo of the line with a large magnification for him to understand. But then I searched for the problem and realized that they are all like that, and I really forgot about it as a problem since it rarely appears, and when it does, you can only see it with effort.

As for the battery, it is not included with the printer. The battery supported according to Canon is the "Canon NB-CP2LI" which is currently no longer available on Skroutz, but even when it was available, it was over 200€. Instead of getting such an expensive battery that is only used in one device, you can get a Power Station like the "EcoFlow River 2 256ah", which is at the same price but you can connect any other device you want on top of it. I use the printer in combination with this Power Station without any problems. (Of course, such a solution adds volume and weight)

The Canon Selphy CP1500 is a printer that truly offers quality results, combining ease of use (wireless and wired connection with mobile devices & laptops) with portability (small size, option to use without external power supply, with a separate battery that is available at an additional cost...).

From my experience so far and considering that this printer is mainly aimed at home users, I have been quite satisfied! The quality it provides is satisfactory, although it cannot be compared to higher-end and more expensive printers. The application offers many options and is quite stable in its connection with the printer, making the experience quite easy! Additionally, I should mention that due to its printing method, it does not use traditional ink cartridges or printheads, so it does not require maintenance and there is not a high likelihood of damage. However, only time will tell!

Each print takes about 20 seconds and compared to the previous model (CP1300), it has the advantage that it applies a protective film in the final stage, so that the photo has better durability over time.
A major limitation is the predefined size of the paper, but with the options provided by the app, you can choose smaller sizes or even easily create your own collages.

In summary, if someone is aware of the capabilities and limitations of the Canon CP1500, I believe they will be quite satisfied with this product!

P.S.
A very interesting video of the previous model (CP1300) that personally helped me understand what to expect in terms of usage and print quality...

https://www.youtube.com/watch?v=LOl7HQFAFaU