I ordered up a Halo Battery pack from sniper1rfa. It's a great setup, and he was wonderful to deal with.
There was a small mixup on shipping, which sniper1rfa bent over backwards to fix. His response to a lil mixup was stunningly good, which I think is more telling than anything else. If I decide to buy any more battery packs, I will not hesitate to have sniper1rfa make them.