*Battery Bulk*: My big goal was to get 60 miles (100km) worth of range at highway speeds. I need ~140-200 watt-hours to travel a mile at those speeds.
I have these 4x5 battery holders, an 18650's average voltage through it's discharge curve is ~3.7, maybe 3.75v, cells are roughly 2000mah each (good ones are 2600, I'll stuff in as many of those as possible), so each 4x5 brick of 20 cells is roughly 150 watt-hours and weighs 2 lbs. *Battery Weight*: At a brick a mile, I need to find room to fit 60 of the bricks in the frame (9000 watt-hours). Since I'm doing strings of 11, might as well round it up or down to 55 or 66 bricks. It'll weigh about 120 lbs to do that. Motor is 92lbs, so motor+battery is 212 lbs, plus the weight of wiring and the battery enclosure. The original engine according to spec was 181 lbs dry. Plus fluids. Plus exhaust. Plus fuel. I should weigh the bike now and compare it to the 467lbs it was originally. In any case, I'm in the right ballpark I'd say. *Battery Sizing Layout*: My first big happy surprise. I had more room in the frame than I thought. 66 bricks is roughly 2 milk crates worth, bulk-wise. Just looking at the bike, I figured there was no way I'd find room to fit them. I've been putting it off forever, but tonight I dummied up a bunch of empty battery trays and started seeing where they could go. 1 - Below radiator, in front of frame: 4x4 bricks, +4 if I remove radiator. 16-20 total. 2 - Below/between frame, below motor (as in pic): 3x4 bricks. If I double-stack (each stack is 2.5" tall), double that. Brake disc is 6" above ground, so I figure I'm okay with that clearance for city riding? 12 or 24 total. 3 - Beside motor: Sloppily, sticking out of frame, 5 first tier, 8 on second tier, 8 more on third tier. 21. 4 - Above Motor Right: 5x2 bricks. Three tiers. The mounting for the motor sticks out 2" so I have to separate right from left. 30 total. 5 - Above Motor Left: 4x2 bricks. Three tiers, but it's getting ugly to not narrow at the top of the frame. 24 total. 6 - Under Tank: 2x2. Not much space, hard to fit, but room for 4 total. 7 - Above Swingarm Triange: 3x2. 3 tiers. Nice and narrowly tucked, won't interfere with my thighs. 18 total. *Grand total*: 125-141 bricks. Jeez, I only needed room for 66. Heck, I only have enough weight available for 66 (not 250-280 lbs). I don't even have 141x20 = 2820 cells = 21kwh of cells. That's almost as much as a Nissan Leaf. This isn't the layout I'll be using, or even the orientation, it was just the easiest way to slab up cell holders and ballpark the spacing available. If I'm over what I need by at least double... I can afford to make some choices based on cosmetics, not "What used to look like a motorbike now with a bunch of bricks". I can skip the whole row in front of the frame. The 2nd tier below the frame. I can slim a whole row of bricks off of the left and right sides each. Still have room for 66. Easy. Expecting my hubris to bite me later, but, for now I have some breathing room. -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To unsubscribe from this group and stop receiving emails from it, send an email to nighthawk_lovers+unsubscr...@googlegroups.com. To post to this group, send email to nighthawk_lovers@googlegroups.com. Visit this group at https://groups.google.com/group/nighthawk_lovers. For more options, visit https://groups.google.com/d/optout.
