Power requirements for the chanter is USB 5 volt. Micro USB.
To get you going a Mains or Car USB adaptor for phone charging will work or USB port on a computer. The chanter socket is Micro USB, the same as most Android phones.
Most mains power adaptors have the large rectangular USB A socket or has lead hard wired. You will need a USB A to Micro USB lead.........
and a mains extension lead for moving the adaptor about. The mains adaptor will keep working when connected to low power devices such as the chanter.
For portability it is best to use a USB Powerbank.......
There is a problem due to battery saving etc some powerbanks will either not switch ON or not stay ON when powering items that take very low power.....
They think it is a phone that is already charged. The powerbank needs to be able to work in "Low Current Mode".
The older "POWER" branded powerbanks as sold by Poundland etc. worked well and did not switch off on low loads.... and for only £1.00, but they are no longer available.
Poundland now do "GEEK" or "VIDO" brands but some of these will not stay switched ON. There is nothing wrong with them....they just do not work at low power loads.
Even good and expensive brands some behave in the same way.
The problem with reading the datasheets is that they advertise how much power the powerbank can output for phone charging but do not say whether they have a "Low Current Mode" method of operating.
The only way is to try them and see...???
A suitable powerbank that has been tried and works and has a "Low Current Mode" is the XTAR PB2S.
It can be bought from Amazon UK.....They have depot in Salford so you get them quickly in the UK.
Goto link for XTAR PB2S Powerbank on Amazon
The XTAR PB2S will come without batteries but you can buy batteries locally from the Cigarette Vaping shops.
It takes one or two Lithium 18650 batteries and has a display to show the voltage out and the load etc.
It is just a normal charger and you can also use it to charge up your phone or charge bluetooth speaker etc.
Another item that has been tried and works is a cheap "PowerGEEK Wireless Portable Sound Bar" from Poundland.
It is a 300 mm long Speaker and also has its own re-chargeable batteries and USB A power output. It also has Audio aux input.
So it will work as speaker and power for the chanter as one unit. They may be branded "VIDO" now but the same unit.
A possible way to "fool" a power bank is if it has two outputs sockets......plug one in to charge your speaker while the other output is powering the chanter......
That will increase the load on the powerbank an keep it going.