Best battery for Stages power meter

[Andy_Greenhalgh]

I have just bought a second hand stages crank arm. The big issue I am having is on drop out. I have tried switching a round batteries between ones in my heart rate monitors and put a bit of paper on top of the battery to press it in further. It seems to work fine indoors on the same bike, but when out doors it constantly keeps loosing connection. I have tried banging the bike about indoors to check if this is causing any issues compared to the knock you get on the road but it still works fine indoors. Does anyone have any suggestions??