Some Kanger T2's actually fit the Halo battery without the need for an adapter. I had 3 Kanger T2 tanks before my Triton Set arrived, and since the T2's look exactly the same as the Triton Tank, I tried to fit the T2's I had into the Triton battery. Two of them fit, while the other would not fit at all. I was a bit perplexed by this, it would have been nice if they all fit.
I took the Triton battery to the local B&M store and I had them take out 10 T2 batteries to attempt to fit them into my Triton. Only 3 out of ten fit.
As for my other Kanger Tanks (EVOD, T3, MT3s etc) none of them fit the Triton at all, far from it, but sure some of the T2's do... it will not thread in completely, but they do work and I have used them for months now with no issue.