@djibattworkshop they are not so popular here as well

Posted by: @tiberius-8

also i read that disconnecting of the cells could cause the controller to lock the battery - is this true?

 Yes, in some cases it locks the chip permanently. It could be unlocked though using tools like NLBA1. But only for supported chips. Some drones batteries have complex chipset consisting of 2 to 5 extra chips. Permanent Failure flags could be stored in those extra chips too. They not supported by NLBA1 software. 

 In many cases even lock state could be prevented by disconnecting the cells in correct order, so from most positive cell to the ground. Reassembly in reverse order. Then chip should be waked up by connecting a charger for some seconds. 

@djibattworkshop looks like I have hit a brick wall.

Can't buy the batts in Australia and when I found a guy selling cheap new ones in the US he couldn't post them at a cheap rate .

Finding the right cells and replacing them will be a challenge