Thank you for the suggestions, certainly worth considering!
I ended up buying an after market battery from a manufacturer called Jupio. Bought it from a very credible supplier here in Sweden after talking to their customer service and inquiring about the battery.
Perhaps a little bit of gambling from my side but I will start by flying very low and slow to make sure that everything works as it should. It is not a guarantee that the battery will never misbehave but things can happen all the time…
One thing that I’m wondering is how the after market manufacturer go about to design the batteries. Since the DJI batteries are so called “intelligent flight batteries” with built-in firmware, I reckon it’s more to it than just putting some LiPo cells together to get the right voltage and power. I guess that DJI has not released any API:s or similar. Do you guys think that the after market manufacturer do some reverse engineering?