But if you run a 5000 pack relocating that spacer might not work so well correct? I use a few different batteries; 4100, 4500 and 5000. About to buy some 4400 batts soon though, my nanotech 4500 might be toast now. I will not buy anotehr one of those for this heli. But the glaciers have been really good so far for my mini protos. But I will probably stick with Pulse for the E5.