After months of set backs and silly ideas that didn't work I finally have a fully functioning battery pack for my commute up the mountain again! I was experimenting with a triangle frame mount and was just complicating things. I also happen to really dig my ghetto grocery getter 6.6ah strap pack so figured screw it.. go with what you know and what works. K.I.S.S.
So... I built another strap pack of 14s8p 52v nominal and about 11ah assuming around 1.35ah/cell, which I've found is a bit conservative, but I like to underestimate so I'm not caught with my pants off in the middle of the woods. The absolutely gorgeous thing about a "strap pack" is that it's got built in shock absorption. Half my commute is single track, off road and bumpy as hell so any battery mounted to the frame suffers vibration damage a LOT. I was a little worried about my homemade tab welds, but I dead shorted the pack at least twice during the build process and none of the tabs popped off so that sold me that they were fine.
I channeled my inner CammyCC and figured I'd just go square pack because it's so easy. I've got a "tail", but I did that on purpose in case I want to upgrade to 18s it's cake and I already have an 18s charger as well.
About 20 minutes with dremel in hand smoothed out all previous weld blasts etc.
Gots ta be careful though!!! KA-POW!
You can see my "$100" 16v tab welder SCR and cap in the background. Cost me $140, but were I to do it all over I could have done it for $80.
Little blurry, but here's the finished product getting charged up for the first time.
Here's the strap pack mounted up for a test ride. I'll "pretty it up" soon..
I dumped about 7.2ah out of the pack and it still had tons of juice, but I want to cycle it a few times and balance the cells before really sucking it dry. I'm also pleased to report that my ecitypower custom chargers are working great and outputting 58.8v and 6A ~350 watts. So like <2hr charge time. Nice.