Electric Bikes - convince me to go electric rather than gas

You might want to consider something other than gas or electric. I built a small scooter that is pushed along by a sock monkey riding a unicycle.

Yes, I really did!

Link to a short video: http://www.youtube.com/watch?v=ND9pldA56vU

Oh, that ain't right at all! :D

Let me toss another non-cost factor into this discussion. From what I have read, gasoline tends to be more trouble free. I wouldn't have thought that electricity would be troublesome but there seem to be a lot of posts here from people having various difficulties. Could be just 1% of the riders and I'm aware of them only because they post their questions. Hard to tell.

I do have to be careful about how and how long I charge my battery. I also have to consider heat and cold. I also know that access to a charging location (home or work, for me) is a big deal. Makes it hard to go camping with the bike.

It is easier to gas up at the station, but I like the silence and the lack of smell with my electric motor. If I were gong long distances, I would probably want gas or some hybrid version that was described on this thread.

You could always just get one of each.

Yep, right now charge costs don't matter. If buying the packs gets lots cheaper, and electricity gets more expensive (both of which are gradually happening) at some point it'll be worth worrying about. FYI my slow charger is dead silent. I'd wager most are..

And its not far off that you will see fast chargers than can top off your battery in the time a gasoline refill would take. There are already people doing 5 minute charges with lithium batteries, no reason why ebikes can't do the same. Nothing stopping you from carrying your charger with you on the bike. Heres a random link I googled up, there's no reason to doubt it-

http://static.rcgroups.com/forums/attachments/4/4/9/7/4/a1109034-62-A123---Charge-Rates.gif


Riva -

What figure would you put on the on-going cost of batteries using the most long-term economical battery that still delivers 20 mph over a range of 20 miles?

e.g. $500 for 500 cycles at 20 miles per charge = $.05 per mile.

Lets say you do your homework and pick a bargain quality 48v 20ah lifepo4 bat on ebay. That'd be like 1000Wh for $700. Figure 1000 cycles for a reasonable 20 mile trip, equals 20,000 miles total. Thats 3 to 4 cents per mile as far as battery cost. So your math seems about right. And here's a completed auction link if you don't believe that $0.50 per Wh *can get you in to lifepo4-

http://cgi.ebay.com/48V-20AH-LiFePO4-Electric-Scooter-E-Bike-Ping-Battery_W0QQitemZ220294687176

You could adjust the math for the above case, $560, assume only 500 cycles instead of a thousand and still get 5 to 6 cents per mile.

As far as the "no dog in the fight" thing goes on lithium bats, every two wheeler I have is either gas powered or pedal powered, all except one lead acid battery bicycle. Just reporting the facts as I see them currently. I'm too broke to be an early adopter, so I'm reading and waiting. You want to really learn about ebikes, there are other forums out there for you.

And its not far off that you will see fast chargers than can top off your battery in the time a gasoline refill would take.

Charging my 800 watt hour battery in five minutes would require a 9600 watt power supply. A typical 15A 110V outlet provides one fifth of that power, meaning the best I could hope for is a 25 minute charge time, and that with a lossless charger.

Even given the 50A 220V outlet and 90% efficient electronics necessary for a 5 minute charge, I would not want to accept the significant reduction in battery life that fast charging imposes on the batteries commonly used in our bikes. According to Wikipedia (http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery), "rapid charging [LiFePO batteries] will shorten their life-span when compared to traditional trickle charging." The article lists a rate of C/4 (i.e. four+ hour charge time)as recommended, which is, coincidentally, the same rate Optibike uses on their cobalt Li-ion cells. There are claims of fast charging lithium cells (I think I read about nano phosphates) and possibly some commercial availability, but AFAIK they are not used on ebikes yet.

The RC folks get away with 5 minute charges by actively cooling the cells as they charge, which is relatively easy due to the small size of their battery packs. Even so, battery life is undoubtedly reduced.

Right. Like I said, its not far off. Battery technology is moving right along.

Electric dryer type outlets aren't that hard to have installed, I personally had one installed when I had my electrical redone at home, and it didn't add much cost to the job. I also have access to one at work. But if you feel like its too much trouble to get one installed- you could quick charge off of a relatively inexpensive bank of lead acids; a bank like a ups system or solar setup might use. If that turns you off too I guess its going to take more than five minutes, no biggie.