I received my new battery today It's a 900mAh 12c battery. The weight is 42g, which is 2g less than the E-Sky battery My first test fight shows that the helicopter really will fly long with this battery
The back of the package indicates this is made by Yuntong. As I already have a Yuntong battery I am very happy about this. The price was below the limit for Danish VAT so this made it somewhat cheaper.
From my first impression I wouldn't mind buying more of these batteries.
I also made some heat sinks for my motors, but I will tell more about that in a different post.