My daughters love their Lunii (Ma Fabrique à Histoires). They received them as a gift some years ago and still use them almost on a daily basis. The people at Lunii did an awesome job with this product. Furthermore, their software to buy and install new stories supports Linux which is a big plus for me. I had to open the boxes a few times to fix the volume knob and just because I was curious to see how it was made.

I have a few 18650 Li-Ion batteries at home and this evening I decided to try to replace the original battery with one of those. The 18650 fits without any modifications to the casing but it’s a tight fit. I used a protection circuit (undervoltage and overcharging protection) since the original battery has one and to be on the safe side.

The original battery is labeled as 500mAh. The 18650 I put in is at least a 2000mAh so that should be around 4 times more battery life. The Lunii is charging at the moment, I’ll report after a few days of use if it works as expected or not.

UPDATE: after several months of use, I can report that the Liion cell is working great as expected. I did not measure how long the Lunii lasts with this battery but it is clearly much longer than before.