However, with todays battery tech. The hottest pack you can put into one of these bikes is A123 20Ah pouch cells and your only going to get ~12kWh before it starts becoming too heavy.
I wanted to revisit this with respect to the BPM 44/70 modules
I only found one datasheet (PDF)
for a 20Ah pouch cell on A123's site. Maybe it's a high-power chemistry, but it lists the specific energy at 131 Wh/kg.
BrammoBrian hints that the BPM cells are somewhere between 190 and 250 Wh/kg.
The Empulse (placeholder?) specs list the 6.0, 8.0, 10.0 kwh bikes at 360, 390, 420 lbs respectively. If we assume the only difference between the bikes is the battery pack, then the total pack specific energy is around 150 Wh/kg.
2012 Zero S ZF9 is 7.9 kWh nominal, 341 lbs. ZF6 is 5.3 kWh nominal, 297 lbs; pack specific energy is around 130 Wh/kg.
Assuming the Empulse placeholder specs are accurate, then (ignoring packaging) an Empulse 20.0
with current batteries should weigh around 570 lbs
. That's a heavy bike, but nothing like the 700-800 lb full dressers.
Pricing on a 20 kwh model would be stupid right now at retail $1000/kwh. Actual cell cost seems to float between $300-500/kwh depending on whose numbers you believe.. I figure as the bikes are produced in volume we'll see retail pricing on the large packs drop down closer to actual material costs. A 2015 Empulse 20.0 kwh might look something like 200 wh/kg pack, 520 lbs, 80 kw motor, $14-15k retail pricing.
TTXGP and IOM will be interesting this year to see how much pack people are able to cram into their bikes..