Hi there!
I'm new here... i have my own spark since last week... very happy.
I want to ask if somebody have made a battery pack to work with spark.
Im thinking on buy a battery holder to use 10 rechargable sony 2500mAh batteries (1.2v each one) like this:

Click image for larger version. 

Name:	2019-02-07 12_00_30-Window.png 
Views:	36 
Size:	227.5 KB 
ID:	144036

Someone here has done something like that?
Wich power supply range do Spark have?
Thanks!!

Regards..