As I mentioned above. You do need to find out what the actual battery voltage is. For example, a "12V" car battery runs at about 14V during charge. If the same ratio applies to your 60V battery, you are looking at 70V.
I'd advise to aim for a 100V input regulator.

But here is a diagram..
View attachment 205131
The big problem is the input voltage is way too close to the max, and motors generate spikes.
That will kill your regulator and the result could be 60V applied to your 5V device. Just think hard about that before you connect it up.

If you power a 5V speaker with 60V, that just makes it 12 times louder, right? Rock on!

 

I thought the issue was during charging the battery. I was just going to. Unplug it while charging the scooter batter

 

If you are worried that you may exceed the input voltage to the device, you could consider adding this module at the front end which is capable of handling an input voltage of 90V; outputting 12V to the USB adapter.

https://www.ebay.co.uk/itm/30-90V-t...rand=Unbranded&_trksid=p2060778.c100290.m3507

 

That above 90V input device mentioned by @Hymie is the way to go!
Then, just use a car 12V to USB charger. Simple
(Still add cap etc).

 

I think that you would be way better off with a power bank. It could charge your bluetooth devices a number of times. They are inexpensive, and you would not expose yourself to dangerous voltages and possibly damage to your scooter.