I'm a tad over 6' tall and my knees clear by several inches when pedaling. I had a friend visit from London in the UK last week. He's about 5' 6" tall and it was a slight issue for him, but he quickly adjusted to it as we rode my 2 e-bikes. The battery box is only 7" wide and It's not in my way at all. The next e-bike I build I will mount the battery in the same place, but tip it up on it's side so it will only be 5 and 1/2 inches wide. I checked with Ping and they say I can mount the battery in any orientation.
I mounted it on the top frame rail temporarily just to see if it would work okay, and I like it there. I mounted the battery on the other e-bike on the rear rack because, with a front hub motor, it balances the weight better. This bike, with a rear hub motor, has a better weight distribution with the battery farther forward. it looks good to me and handles great. It will stay right where it's at.