Capacitor-powered e-bike

a-dam · #1 (**permalink**) 04-13-2009, 05:29 AM

On one of my last rides (with my 2-stroke MB), I noticed how many places I go that have electical outlets.
A while back I remember hearing about a capacitor-powered cordless screwdriver that charges in 90 seconds. The Coleman FlashCell is probably the one: there may be others. If this technology ever evolved to the point of powering an electric MB for 10 miles, that would do me good most of the time.

Of course, there are lots of issues. "On-the-road" recharging would basically be stealing electricity from parks, gas stations, stores, etc. Personally, I could live with that. You would have to know how much of an amp draw a charge pulls. You wouldn't want to blow a fuse or cause damage on the system you're stealing from. You would have to carry the charger with you (or have it built in - same difference). And you would need a certain amount of cord for tapping into outlets and gas-station bathroom light sockets, for instance.
And big capacitors could probably blow up real good, too.

Sounds pretty cool to me. Whaddya think?

deacon · #2 (**permalink**) 04-13-2009, 07:24 AM

You know that could be the new super hub motor they we are all talking about. They are somehow storing enough batteries inside that hub to make it self contained. A fast charging battery with a super efficient generating capacity in the hub itself might be what is happening with it.

Also that flash recharge has to be in the battery technology.

It looks to me like you get about 1 mile of riding from a 1 hour charge from a 1.5 amp charger with an sla battery. All that is a gross estimate, the real numbers are less of course.

Ways to increase that....

1.With a more efficient battery you would get more range per amp hour of charging. The new lithium polymer batteries are much more efficient I'm told

2.a charger that charges at a higher rate. They say the lith charger is at least 5amps. So the charge time would be 12minutes per mile of use. With more miles per amp probably as well.

3.the amount of regenerative energy created would increase the range of the bike as well. If you regenerated energy at a higher number of amps it would factor in. Maybe that is the real secret of the self contained hub.

This is all just guessing I'm no engineer but that seems to me how it would have to work. There is definitely a relationship between all those things. An improvement in any one part would effect the end result. With the push to E cars the improvements should be coming down the pike much faster than before.

I honestly think that the battery and charging improvements will lead because those are applicable to automobiles directly, but so is regenerative technology so that might be right there with the others.

New technology can actually be applied to bikes quicker than it can to autos, I would think. It is less expensive to put that technology on a bicycle i think. In a car you have to gear up a whole plant, For a bike a guy in the garage can do it. Not me of course, but some guy somewhere can do it.

And for the record I wouldn't have a problem tapping into the power grid either. I expect there will be power stations in the parking lots of municipal buildings one day. For me though the ideal would be exchange stations. No muse no fuss, just switch out your used battery for a charged one for a buck, from a vending machine even.

a-dam · #3 (**permalink**) 04-13-2009, 09:43 PM

Yeah, Deacon. I really like that idea for battery exchange stations. Just like the propane tank refills.
I would pay a dollar for a fresh battery with 10 miles worth of juice. It would probably only cost pennies worth of electricity to recharge, but I don't know if a recharge station could be profitable at a dollar a swap. Recharging batteries should be a lot less hastle than refilling propane tanks. Plus, you could ride home on your rental battery, and recharge it at home yourself. You would only need to exchange it when taking rides longer than 10 miles. I just pulled the 10-mile figure out of the air because on my long rides, there's a town about every 10 miles along the way.

What is the range-per-charge of a cheap SLA anyway? I have no experience with electric bikes at all.

deacon · #4 (**permalink**) 04-13-2009, 09:59 PM

It seems to depend on a lot of factors. One of the guys got 12 miles on his 12am battery pack. He pedals alot. I get about 6 miles on mine if I ride it mostly motor and pedal only a little bit. With a double pack I can ride mostly motor only and get 10 to 12 miles. The other guy would get about 25 I think.

You can buy different size batteries and pack them up anyway you want. I tow mine packs on a trailer behind me whenever I can. I also have a rack on the back of the bike for when I can't make the trailer work. I have a bike I just finished that won't let the trailer work.

Clotho · #5 (**permalink**) 06-03-2009, 07:13 AM

Hey Vat,

I see you're stirring the pot

Thank you for bringing this thread to my attention. As of late I have been doing a fair bit of research into battery technology/battery chemistry and related charging. I found a great deal of good information at: BatteryUniversity.com I will have to research the Coleman FlashCell you speak of. Quite often the ebike guys grab on to new tech pretty fast and give it a whirl. Last time I looked, everyones favorite battery tech was LiPO4.

My current project includes an electric component.

What if you didn't have to plug into other peoples power to ride your bike back home? What if you brought your 110v with you? Honda Portable Generator

I first thought about this about 5 years ago when I first added a Crystalyte motor to my China Girl. I was unimpressed with the results at the time and abandoned that project. The hub motor and sla's have sat idle all this time.

Then someone posted this video and I got thinking about it again: Series linked Tribrid Trike.

Your trailer is an interesting thought Deacon. I remember wishing I had a trailer with a generator. The ones available at the time were so heavy they would have required one.

deacon · #6 (**permalink**) 06-17-2009, 08:57 AM

I just finished a little very minor addition to my trailer. What I did was to make my trailer frame from a couple of "L" brackets welded together. Then I set some 3/8 inch bolts in them and welded them in place. I ran my scooter wheels and axles through the L brackets so that the bed of the trailer is about three inches lower than the wheels. It makes the trailer low to the pavement but adds some stability.

I screwed a wooden box I had laying around to the L bracket and install the batteries into it. So far that is just a low riding trailer, but I saw something someone else on here did and I wondered would a basket fit over the box and clear the wheels.

So I found a wire basket I had laying around and I made some hinges from a couple of clamps used to hold electrical conduit to the wall. I just bent them into a U and put them around the edge of the basket so that it would hinge back.

The point is that basket would hold a generator very easily. It would be right over the batteries and all in a self contained package. You could just hook it up and go. If you needed to the whole thing would come off to go into the truck of your car and the bike would fit on a bike rack. Easy to move it around as well as convenient to ride.

geeksquid · #7 (**permalink**) 08-30-2009, 08:20 PM

Quote:

Originally Posted by Clotho

Hey Vat,

I see you're stirring the pot

Thank you for bringing this thread to my attention. As of late I have been doing a fair bit of research into battery technology/battery chemistry and related charging. I found a great deal of good information at: BatteryUniversity.com I will have to research the Coleman FlashCell you speak of. Quite often the ebike guys grab on to new tech pretty fast and give it a whirl. Last time I looked, everyones favorite battery tech was LiPO4.

My current project includes an electric component.

What if you didn't have to plug into other peoples power to ride your bike back home? What if you brought your 110v with you? Honda Portable Generator

I first thought about this about 5 years ago when I first added a Crystalyte motor to my China Girl. I was unimpressed with the results at the time and abandoned that project. The hub motor and sla's have sat idle all this time.

Then someone posted this video and I got thinking about it again: Series linked Tribrid Trike.

Your trailer is an interesting thought Deacon. I remember wishing I had a trailer with a generator. The ones available at the time were so heavy they would have required one.

But that Honda generator is 12v DC output, not AC 110. Of course, it would still charge batteries, or you could use a DC to AC inverter.

myocardia · #8 (**permalink**) 08-30-2009, 11:55 PM

Quote:

Originally Posted by geeksquid

But that Honda generator is 12v DC output, not AC 110. Of course, it would still charge batteries, or you could use a DC to AC inverter.

That says 120 volts, not 12.0 volts.

BTW, my dad owns that exact generator, and it outputs 120V AC. It does have the capability to output a few amps (8A, I think) of ~13.8V DC, which is exactly what you want for recharging batteries. You don't want to have to carry around a separate charger, when you could just charge the batteries directly. It's also the most fuel efficient generator I've ever seen or even heard about.

geeksquid · #9 (**permalink**) 08-31-2009, 02:49 AM

Quote:

Originally Posted by myocardia

That says 120 volts, not 12.0 volts.

BTW, my dad owns that exact generator, and it outputs 120V AC. It does have the capability to output a few amps (8A, I think) of ~13.8V DC, which is exactly what you want for recharging batteries. You don't want to have to carry around a separate charger, when you could just charge the batteries directly. It's also the most fuel efficient generator I've ever seen or even heard about.

Yes, I was looking at the description at the bottom of the page and not the top. But still, you'd need to use the charger that's appropriate for your bike or battery's setup, i.e. 24volt, and since the generator does have an inverter built in, you'd need to plug your charger into the 120v generator receptacle as you normally would at home. No way to charge the batteries direct from the generator's 12v output.

myocardia · #10 (**permalink**) 08-31-2009, 06:50 PM

Quote:

Originally Posted by geeksquid

But still, you'd need to use the charger that's appropriate for your bike or battery's setup, i.e. 24volt, and since the generator does have an inverter built in, you'd need to plug your charger into the 120v generator receptacle as you normally would at home. No way to charge the batteries direct from the generator's 12v output.

I can assure you that there are multiple ways to charge multiple 12V batteries using a single 14V input. There are only three reasons that this particular Honda generator is used by everyone who wants a carry-along generator for an EV, and the fact that it has the capability to output 8A of 13.8-14.0V power is one of them. If you were to do it your way, charging while riding wouldn't be possible. If you would like me to go into more detail later tonight when I have more time, I can.