luna makes the best aftermarket/custom e-bike batteries on the market.
I have read some of the reviews of the battery packs that are made by Luna and all I can say is this, the complaint's are all bull except for the weak tabs on the mount plate. Other then that this battery does way better then you think. I have my battery mounted to the underside of my full suspension mountain bike with mud, rocks and everything else hitting it and never had one problem. I jump my bike with abandon off of everything I can see and the pack has never come loose. Just don't dick around with your pack taking it on and off needlessly and the tabs won't break.