Pull up the battery connection pin? With something small and thin (paperclip) you can wiggle it upwards so it makes a connection...
I still don't LIKE the ProTank on my VAMO, as it doesn't rest on the "collar" but above it - stressing the 510
threads, which are already imperfect. So I stick to using T3's and EVOD's on my VAMO - which work great.
(ProTank is perfect on my SVD)