Thank you very much mahonj and Anne !!

I pedal a high performance e-bike from Optibike in Boulder, CO. It had an internal, 36V, 720Whr battery.

My ranges have been 46mi at 23mph, or 35 miles at 25mph - depends on how much throttle I use and effort from me.

I commute 25 mile 2x a day. Great commutter bike.

expensive: www.optibike.com

I'd like to get excited about a great new battery but this sounds ho-hum to me. After price, energy density is probably the second most important factor to most ebikers. Power density is vital for racing but for typical use energy density is more important.

These batteries have good power density but crappy energy density. And the crappy energy density makes the super long life of 3,000+ cycles seem irrelevant.

Consider that these batteries have half the capacity density and only 2/3rds the voltage per cell of typical li-ion cells.

Thus for an equivalent weight of batteries a pack made from these cells would only give 0.50(ah)*0.66(v) = 0.33 of the range of my pack made from the old standard cells.

Most folks consider a pack dead after it loses 1/3 of its capacity. For my old packs that took a little over 3 years. After 6 years it is down to about 35% of its original capacity. This is a *really* worn out pack. And it's still a little better than what a pack of these cells would be new.

Being able to super fast charge might be nice, but high powered chargers tend to be big and expensive. Unlikely that you'll find one you'd want to take with. And if you're going home to recharge odds are you'll be able to find something to do for the half hour to an hour it takes to get to 80% or so which ought to be enough for most needs.

I put a wilderness energy 16" front wheel on a Bike e recumbent (stock tires, about a 35lb bike, 150 lb rider) and got 35 miles min per charge on fresh 12Ah 36V gel cell pack. Moderately hilly terrain, average speed 16 or so mph, I commuted 17 miles each way to work and the low battery indicator never came on at the end of the day (I hope it wasn't a 24V throttle hehe). Have now switched to 3 phase brushless. I find the best gear comes from Canada.

Regenerative braking on bicycles isn't worth the extra weight, unless the system is already designed for full range traveling. Since a bike+rider is such a low weight, there isn't much kinetic energy to be stored when braking, unless you are trying to stop while going down a steep hill.
Or if you are forced to stop every minute or so in heavy urban traffic. But the beauty of a bike is that you don't need to brake or stop nearly as often as car.

I've been in competitive road cycling for 10 years and can tell you that a typical recreational "comfort" bike takes considerably more power to move than a road racing bike. I built my own electric bike, used a 600watt (continuous) 24v motor and two 12v 17ah SLA batteries (408 watt hours). I put this on a road bike that I could still pedal and coast on. Range was 12-15 miles at 23mph average speed, AT FIRST. Then it dropped after 5 cycles to about 5-7 miles at the same speed.

Quality electric bikes simply cost too much for the average person who would use them for recreation and commuting. They need to have the range to enable the rider to go where they need to go without much pedaling at all. No one wants to get all sweaty commuting to work. LiPo batteries need to come down in cost, then the ebike will prosper. They will become great for many urban commuters.
I can't stand driving my car in the city!! Parking tickets, traffic, time loss!