and so you should be able to carry THREE mavic pro batteries as hand luggage (per person), as they are 43.6Wh each - make sure though they are not fully charged and have battery terminals covered. I've got a set of battery covers off amazon (for mavic and 3 batteries) for when I take mine abroad.
I was in Scottland on 05.2018. I was flying from Berlin to Glasgow.MP, 3 batteries with me. And without the slightest problem. Nobody checked what I had with me. For sure all the batteries were in lipo safe bag and I took off propellers. More scaring with drones in airplanes than it's worth.
I went BA to Barcelona couple of weeks ago Mavic Pro 3 battery’s carry on chucked it all in there bin thro scanner out other side thank you very much. Put the nippers bag thro he got stopped wanted to re scan his Nintendo switch and do swab on it I laughed
No issues whatsoever through airport security (Gatwick and Bristol) when flying to European destinations with EasyJet and Ryanair, security seem bothered about laptops and tablets, didn't bat an eyelid at drone.