Technical 39 Borg clock

Hi
I have an original 39 mercury mechanical borg clock with electro magnetic rewind. I got it cleaned up and lubricated .
Till now i had it on a power supply driven with 6v.
It works great and is very precise on a whole day running. Really fascinating little piece!

Here comes my question:
Are those clocks rated for 12v too or do i need to reduce voltage on a 12v car?
Any experience/advice?
Thanks

 

Run it on 6v.