If you had a million dollars to invest in e-bikes

[1of3]

Batteries are the hold-up for EV's.

hi.... you've got tons more knowledge & experience than I do w/batteries, what think about these as compared to the type used in pings 48v 20 amp packs.....? Think they'd last per trip as long...?

thanx.......

http://www.robotmarketplace.com/products/battery_build_main.html

 

[SpeedEBikes]

Batteries are the hold-up for EV's.

hi.... you've got tons more knowledge & experience than I do w/batteries, what think about these as compared to the type used in pings 48v 20 amp packs.....? Think they'd last per trip as long...?

thanx.......

http://www.robotmarketplace.com/products/battery_build_main.html

They are 4600 mah. Not much capacity for typical ebike setups. I'm guessing you meant to say a ping 48v 20AH pack as opposed to a 20 amp pack. If so, these nimh have less than a quarter the capacity. You can parallel them in discharge but not while charging (unless you seriously under charge them). Nimh and Nicad have the awkward trait of having their voltage drop when they reach full charge. That makes them unsuitable for parallel charging. I imagine you wouldn't even want to parallel them when they are still hot off the charger. You'd likely need to wait until they've cooled and the voltage had settled a little. Or you could risk lesser charged cells dumping current into an overcharged cell and driving it into thermal runaway. Nimh also suck for cold weather use and for intermittent/sporadic use do to high self discharge.

I've got some Sanyo eneloop AA nimh cells. They have very low self discharge and don't degrade fast in storage. They might make good ebike batteries if they can scale them up to a larger format.

 

[todayican2]

I would build a prototype of a 3 wheeler. (2 seat, highway capable, probably a hybrid) and get uncle Sam to invest another few million via that new DOE funding that passed congress friday.

 

[MitchJi]

Hi Greg,

I'd build (with some hired help) a Full Suspension Tadpole Trike based on Julian Edgars "Chalky" (he describes the Trike but not in sufficient detail to be easily built).

I'd modify the basic design to accommodate batteries in the frame and add weather protection equivalent to the Lorax Hauler (Lorax picture below):

Links to all the seven part Air Suspension Trike articles here:

Some individual links and excerpts below:
http://www.autospeed.com/cms/search/index.html?keywords=chalky+&x=813&y=7

Part 1:
http://www.autospeed.com/cms/A_111091/article.html

This type of vehicle can be easily home constructed. You don’t need large facilities; you don’t need expensive gear like metal shears or metal benders. In fact, if you get someone else to do the welding, a vehicle like this can be constructed with just hand tools. If you buy an oxy-acetylene welding set-up, you can do everything yourself.

Part 2:
http://www.autospeed.com/cms/A_111092/article.html

On a road-going HPV, think that a minimum of 100mm of suspension travel is required, and for best results, 130 – 150mm is better. Note that I am not talking about riding over mountain bike terrain, jumping off dirt mounds or performing other stunts. I am talking about the required suspension travel to give a really good ride quality on a wide variety of real-world roads, including unexpected potholes and sudden drops. Use a shorter travel and you’ll need stiffer springs to avoid bottoming-out – and there goes your ride quality!

After a lot of testing and investigation, I think that the compact industrial range of Firestone rolling-lip airbag springs give by far the best combination of:

• 
  * Spring characteristics - gently rising rate that steepens near full compression
  * Utility - the spring ends don’t have to be always parallel, and the springs are durable in rain, hail or shine
  * Mass - the 4001 series I use are 350 grams each
  * Stiction - there is none at all in the spring
  * Size - about as compact as the equivalent steel coil spring, but without the fatigue problems that can occur in metal springs not very carefully designed
  * Adjustment – the air pressure within the springs is easily altered by the use of a bike pump, allowing static deflection to be kept constant irrespective of load

However, the springs are expensive – about three times the price of having steel coil springs custom made. Damping also needs to be performed separately, which adds weight and packaging complexity to many suspension designs.

Part 7:
http://www.autospeed.com/cms/A_111232/article.html

First testing results

I found I could throw the machine around quite phenomenally. I haven’t yet measured max lateral acceleration but it’s probably the highest of any recumbent trike I have ridden.

Rather than continue this series next week, I think that at this time I will stop for a longer period. Chalky has shown itself to be fundamentally a good design with:

• * An excellent ability to be broken down into a small package
  * Excellent comfort on most surfaces
  * Very good handling
  * Good steering
  * Adequate frame stiffness

It needs further development in:

• * Roll control
  * Steering handlebar positioning
  * ...and a few other minor areas
  

I’ll get back to you further down the track when these issues - and any others that may arise – are solved. But for now, if you are interested in building a recumbent trike, Chalky has some excellent ideas that can be followed.