UPDATED 7/24/2022:
I created this video in mid-2021 using a more easy to find battery you'll see in this video. Since I created this video, I've not changed the battery yet. New battery has it's pros/cons, as you'll find in the video.

ORIGINAL POST:
I've been trying to track down some CR1620 batteries for my car's remote for about 6 months now, with no luck. I'm afraid if I don't find something soon, the batteries on my spare remote will also run out and I'll have to resort to using the key. Instead, I've decided I'm going to modify my remote to either accept another size of coin cell, if not multiple sizes. To see how I do this, stay tuned.

Outro music track provided by Google Audio Library.
🎼 Track: by Dyalla - "Hippo"
🔗 from Google Audio Library (search YouTube)

Outro music track provided by Google Audio Library.
🎼 Track: by Dan Henig - "Subway Dreams"
🔗 from Google Audio Library (search YouTube)