I'm looking for a quality battery pack (preferably including Hailong type enclosure), which my research tells me (correct me if I'm wrong) means brand name (non-Chinese) cells. Unfortunately the only brand name cell packs I can find are more than I want to spend (say $400 max, preferably less). For example eBay is full of 48V * 17.5Ah = 840Wh packs built of Samsung 35E cells but they are $500+. Thing is I'd be happy with as little as 400-500Wh (flexible on voltage). Seems like at $5 for a 3.6 V * 2.5 Ah = 9 Wh 18650 cell, that should be very doable for less than $400. But the marketplace is failing me. Any tips? Do I have to borrow a spot welder and DIY? Thanks!