Interestingly, the FAQ page says this: Can I play the Songbook while it’s charging? Yes! You can use the Songbook Max while it’s charging. Please note that the batteries will not charge while the Songbook Max is in use. It only charges while not being in use. So basically you CAN leave it plugged in, it just won't charge
O my goodness!!! Let’s try this for a third time lol. SO - lately I have been using the little white cube iPhone charger to charge it. I run the SBM until it’s dead bc there are no outlets nearby for easy charging. The little apple cube charger must be too weak to run the SMB from a dead state. I plugged in a much bigger charging block that I was using previously and behold, it works! I thought I remember playing it when plugged in. Mystery solved. From GPT: The iPhone charger cannot supply enough power for the SongBook MAX to boot + play audio when the battery is at 0%.
Found the owners manual. Here's the section about charging: Leaving the SongBook MAX plugged for long periods of time when not in use may cause premature wear to the batteries. There is no harm in operating the SongBook MAX with the power supply, however charge time will be affected. The SongBook MAX is always running off the battery, even when plugged in and charging. FM and DAB reception may be effected when the SongBook MAX is powered on and charging. SongBook supports USB PD Fast charging via the USB-C Charge Port. The power delivered by the charger must be between min 5 Watts required by the Songbook, and max 30 Watts in order to achieve the maximum charging speed. For fastest charging, use a USB-C PD Charger capable of delivering 15V 1.5A.
