So, I have a Nintendo Switch that I bought back in 2017 when they first came out. I never played it much (the only game I finished was Breath of the Wild because it was genuinely amazing). It mostly sat in my desk's drawer untouched. I used to love video games as a kid (played the NDS to death) but my interest in them died in my early adult years.
Anyway. What my rare usage of the Switch taught me is that it discharges itself to zero even if left unpowered completely. That always annoyed me because on the occasion where I did want to use it, I had to charge it back to 100% and wait a lot. It's also really bad for the battery. My 3DS doesn't do that. It doesn't loose charge and is ready to be used even if you don't power it on for years.
Last summer, I decided to mod it with a Picofly chip. I like soldering (been at it for years) and had heard all about how challenging the installation is, and how most people fail it. So, I bought one, and installed it myself successfully. It was so much fun and I now have a fully unlocked Switch. Of course, after I had my fun modding it, I shelved it again.
Then today, I felt like playing a game again, so I put it to charge to 100% overnight as usual. But to my absolute shock and surprise, as soon as I plugged it in, it booted to Hekate and showed me 100% battery level. I don't know how (and I can't find any info online) but it appears that the modchip somehow fixed the discharge problem.
That alone made the mod worth it, so I'm happy!