My kids have this wonderful radio called Lunii , a “story maker”. That’s great, but the battery is not big enough and I decided to take a look.
The standard battery is a classic 503035 that you can find anywhere on internet for a few euros. It’s a 3,7V – 500mAh battery.
Good for us, it had a big brother, the 103450, a 3,7V – 1800mAh battery. You can also find it easily on internet.
Replacing it was easy (make sure of the polarity of the battery before replacing it, red on red, black on black). I will do a 3d-printed box to maintain it inside the Lunii.