High torque velomobile

[jawnn]

Living off the grid with inadequate solar, my landlord trucks in batteries daily. So I need to charge up in town.

What kind of batteries will charge fast? Like 30 minutes at 60 amps?

I’m looking at dry cells, something like 3-4” think to fit on either side of the frame, dry cells? Maybe two, with a switch between?

If I need 25ah what size battery do I need? 21.6ah is 80% of 27.

Lithium needs more storage remaining in the battery? Saving only half the weight of the lead?

I am going to need a good monitor.

If my top speed is 25 will the 12volts still work?

I should find topographic maps to estimate the total over all rise.

 

[jawnn]

Lightfoot trikes are so top heavy that the only way to keep them from rolling is to place 50lb batterys at each of the rear wheels. I have ridden one of these and was able to make the rear wheels leave the ground at slow speed. I also do not like the swing steer.

The only delta trike that I would trust would be leaning and with a 40 degree seat angle, and still have independent steering with zero trail.(not a lean steer trike).

I am hoping that you will get interested in experimenting with these tries and actually build one or two.




this one could be good : http://www.maxmatic.com/soohoo.htm

this one would very nice but way too expensive http://www.youtube.com/watch?v=kfmg53kPJMg&feature=related

But I am thinking about something like this with a recumbent seat: http://apax.ca/
Maybe I could desigh it.

 

[chuck]

Jawnn,

OK, you want to build an electric vehicle.
You need it to haul 600 lbs minimum.
It must be able to climb up to a 16% grade.
It needs a 30 mile range.
15 mph max speed.
Must be stable.
Good stopping ability.
Cannot be charged at home.
I assume you do not want a vehicle that needs to be insured.
I assume you do not want a vehicle that needs to have license plates, title and registration fees.

Jawnn, this is a very tough vehicle to design into a three wheeler using any bicycle components.



This bike, using light motorcyle parts, will, haul 600 lbs, climb a 16% grade, get a 30 mile range, attain a 15 mph top speed, be stable, be stoppable, charged in town.
I do not know if it will need to be insured, licensed, titled and registered in your state.

Fairly easy to build, enough room for all of the drivetrain components and batteries.

Will I design a leaning tadpole 3 wheeler? No, because it not practical for your application. And its complexity also gives rise to expensive components, a lot of labor hours, a lot of design time. I built the above bike in about 40 hours, lock, stock and barrel. The components and a light motorcyle donor, maybe 3000 dollars. What you want would probably be in the range of 200 to 300 hours, maybe more, too get it right. If I billed 30 dollars an hour, I would be broke. This is a project for a do it yourselfer with a lot of time, a lot of tools, a lot of experiance, strong mathematical ablility, good engineering skills, extremely talented layout ability, and the ability to work with very tight manufacturing tolerances.

For a one of a kind vehicle. To stay in business, I have to charge for my time, do the math, a three wheeler just is not an ideal vehicle for your application. For a one off vehicle, 10,000 to 15,000 dollars, ,,,,,,

A two wheeler with light motorcycle components is practical. On a scale of 1 to 10, the vehicle you want rates a 1, the vehicle in the picture rates a 10, in my opinion, based on what we have discussed.

chuck

 

[jawnn]

There is nothing practical about a 1200lb bicycle if you have an arthritic lower spine and carpel tunnel syndrome as well as the worn out knees.

For now I am going to rig my trike with 12volts.

I would be glad to pay you 20thousand dollars for the machine that I envision http://www.go-one.us/Pictures_of_go-one3.html. But it is going to have to wait until I win the lottery. I will just build a rocket trike for my self later.

Is any of this correct? where do I get the belts and pulleys? what else do I need?


Battery MK 8A22NF AGM 12v 55ah

Circuit Breaker Type 1 Auto Reset 35 Amp Plastic Housing



Switch Heavy Duty Master With "T" Handle



Alltrax Motor Speed Controller AXE2444 PM or Series Programmable



Motor Mars ME-0909 Permanent Magnet DC 4 HP Pancake Brushed Vented


Cable Welding 2 Gauge - Red



Throttle Hall 0-5V Twist with Style Grip

Sprocket Motor Drive Type B 35 Pitch - 7/8" Bore - 18 Teeth


Sprocket Motor Drive Type B 35 Pitch - 7/8" Bore - 26 Teeth


Sprocket Motor Drive Type B 35 Pitch - 7/8" Bore - 16 Teeth


Roller Chain 40 Pitch 10 feet

 

[chuck]

OK Jawnn,

I think that trike in the previous post is just a little beyond my capabilities, but, you win the lottery and buy one for me too.

This is for a 12 volt system, the drivetrain parts need to be #40 chain.

The motor sprocket parts, 17 tooth for #40 chain
http://www.surpluscenter.com/item.asp?item=1-2828-17&catname=powerTrans
You will need to go to your local bearing supplier to get the 7/8 inch bore 1210 taper lock bushing for this 17 tooth sprocket.

The wheel sprocket, 72 tooth for #40 chain
http://www.surpluscenter.com/item.asp?item=1-1979-72&catname=powerTrans

The #40 chain, 10 foot length
http://www.surpluscenter.com/item.asp?item=1-1163-40&catname=powerTrans

#40 chain removable link, buy 2 or 3 of these
http://www.surpluscenter.com/item.asp?item=1-1087-40&catname=powerTrans

Chain breaker tool, the pins on #40 chain are mushroomed, the head of the pin must be ground off, then the chain breaker is used, the pins are not re-usable.
http://www.surpluscenter.com/item.asp?item=14-1037&catname=powerTrans

Well, that should be it for the drivetrain.

chuck

 

[chuck]

Jawnn,

fuse
http://www.cloudelectric.com/product_p/fu-mega250.htm

contactor
http://www.cloudelectric.com/product_p/sw-20257-7.htm

pre charge resistor
http://www.cloudelectric.com/product_p/rs-kit-pcr-220.htm

throttle, many here, if possible, the twist grip magura has lasted me probably 10,000 miles with no problems
http://www.cloudelectric.com/category_s/8721.htm

You should check electricmotorsport.com or email them for a qoute, they are located somewhere in the northwest USA, They sell all of the electrical parts you need.

There are many suppliers of these parts, hopefully others here will chime in.

chuck

 

[chuck]

Now Jawnn,

With the restrictions you have placed on your ability to charge your battery, a lead battery is not really a good choice.
Here is why.
Lead is finnicky.
It must be completely charged after each use. Even with high charge rates the length of time to balance a lead battery is still around 5 hours or more, really depends on the type of lead battery. Lead batteries for ev's should be kept on a float charge 24/7 when not in service. This helps to completely charge the cells and assure long life.

Agm batteries

I am not familiar with the MK brand.

I am very familiar with the odyssey brand.
sears sells this battery and charger for about 300 dollars. It is an odyssey battery. I use two of the following batteries and two of the following chargers.
http://www.sears.com/shc/s/p_10153_12605_02850134000P?prdNo=6&blockNo=6&blockType=L6
http://www.sears.com/shc/s/p_10153_12605_02871227000P?prdNo=22&blockNo=22&blockType=L22

If you could locate the proper charger, the odyssey battery is the fastest charging battery out there in the lead variety, but, it still takes time to properly finish charge them.

This diehard battery would give you pretty good range at 15 mph, wheels aligned, no dragging brakes etc.
The warranty is very good, keep your reciepts and fill out your warranty cards.
Pretty steep price, spend a little more and go thundersky.

The thundersky (lithium iron phospate?) does not need to be charged after use. Will have 3, 4, 5, 6 times more recharge cycles. Will weigh less. On the forum here there are many who use standard automatic lead battery chargers with this type of battery.

I think 4 of these thundersky batteries is about equivalent to a 12 volt lead battery. Purchase one 12 volt charger, and one individual cell charger to balance the individual cells if any cells do not charge completely. Pretty simple.

If you are not electrically challenged, these batteries can be charged at a pretty good clip. I don't know the specifics charge scheme for this type of battery. Remember, generally, the faster a battery is charged and discharged, the shorter the cycle life.

chuck

 

[chuck]

Jawnn,

I understand about your bad knees, arthritic back and carpal tunnel. This is why I think something similar to what I built may work for you. If it is legal, then even better.

I have a big fat motorcycle seat on mine. Very comfy. Aftermarket Harley seat, cost $65
Front and rear suspension, easy on the spine.
Easy to get off and on.
Great handling.
No weight on my wrists.
Great brakes.
Easy to park, easy to push around,

Easy on the knees, because it does not have pedals, it is not pedal powered, only electric powered.

For your specifications, base the design using motorcycle parts, 600 lb gross vehicle weights would be no problem.

chuck

 

[jawnn]

I calculated with my feeble math the pulleys and sprockets that would yield a little more than 15mph at 1066 rpm…. but is that max speed or cursing speed.
3.5” to 8” pulley then 14 to 26 sprockets….well I may have to use 17 to 28? sprockets giving me more speed but will that effect the hill climbing abilities at 12 volts? Do you know the actual ID of the sprockets at cloud electric? and the key way size? The axle I got measures 14 and 5/16th inch (365mm) long with 95mm of .787 or .788” diameter for the sprockets and 66mm for the wheel hub. 190mm in-between. And a keyway of .233”....I may have to machine some thing to fit.

Two stage is still the way to go for this trike.where can I get the belt?


If I were to loose the balance of your 200lb bike I would wrench the hell out of my spine trying to not drop it and destroy the batterys.

I don't realy care if the mars 909 is legal at 12 volts but it would be good to know how close it is to 1000 watts.

is this the right one for 12 volts? Resistor 220 ohm Pre-Charge for 24-36 Volt Contactors


wow these look like realy good batterys (Thundersky 12volt 20ah ) but which one do I need?

 

[chuck]

Jawnn,
Remember, the battery supplies the power. A 20 amp hour thundersky will not provide the power you need for hill climbing.

The amp hour rating is a energy content rate. This means that this battery will supply 20 amps for one hour. Four 20 amp hour cells wired in series makes a nominal ( kind of similar to a 2x4, its nominal rating, it is really 1 1/2 by 3 1/2 inch piece of lumber) at 12 volts will supply about 250 watts for one hour. Or about 15 miles on your ride with no hills. For 30 miles at 15 miles per hour you need 40 amp hours at 12 volts Nominally. The reality is, 80 percent discharge max for good life, you need more for cold weather, you need a higher current capability for your hill climbing,,,,, a 60 amp hour thundersky is about the minimum battery you should consider.

This is the thundersky battery I am recommending, now wait, I have never used anything other than lead, just read a lot of technical junk on these.
http://elitepowersolutions.com/products/product_info.php?cPath=16&products_id=96&osCsid=a8bcef8873621b73740d10cbcfc99405

Now, the thundersky battery needs to be discussed, how the balancers work etc. Also, what charger to buy. I read about the balancers on an electric car forum, the balancers do not protect the battery from overcharge, over discharge, etc. They only balance at a very slow rate. Only a voltmeter will tell you what the state of charge is for a particular cell. What this means is that until you get to know your battery, a lot of voltmeter readings need to be taken for several rides so that you can understand the packs behavior. Takes some experiance to learn this.

The 60 amp hour 12 volt thundersky specs:
- Nominal Voltage: 12.8V (4X 3.2 V)
- Nominal Capacity: 60 Ah
- LiFePO4 chemistry
- Operation Voltage Range: 11.2 to 14.4V
- Weight: 8.7 kg or 19.2 lbs
- Dimension: 116X252X205 mm or 4.6X9.9X8.1 in
- Max Charging Current: 3C
- Max Discharge Current: 2C (continuous) / 10C (impulse)
- Cycle Life : 1500 (80%DOD)
- Operating Temperature: -20 to 65 C or -4 to 149 F
- Self Discharge Rate: <3% monthly
- Accessories included: jumpers, bolts, washers, split washers and plastic covers


Let me post, then I will discuss the drive train.

chuck

 

[chuck]

Jawnn,
Multiply your measurements in inches by 25.4 to get millimeters.
Your axle is probably a 20 millimeter shaft with a 6 millimeter keyway.

The 15 mph using a 17 tooth driver and a 72 tooth driven is cruising speed. The vehicle will travel faster, but the motors efficiency will plummet, wasting the energy content of the battery. You should invest in a cheap bike computer to monitor your speed. Also, traveling faster, as the physics of wind resistance increase, you will not travel as far.

A single stage reduction is the way to go with the 909 motor at 12 volts and 1066 rpm. A two stage reduction at these rpms will hurt efficiency. I understand the inability to mount sprockets larger than 5.5 inches. Get a longer axle and mount the 72 tooth sprocket next to the wheel.

The 72 tooth #40 sprocket is 11 3/4 inches in diameter. Hubs for this sprocket are located on the page I posted above, the bore is 2 inches, buy a hub a little undersized and have a machine shop bore it for you to match your axle.

The 909 motor at 12 volts would nominally rate 1200 watts. Peak at 3600 watts
The controller at 12 volts would nominally rate 1500 watts, peak at 3600 watts
The thundersky batteries are nominally rated at 1536 watts, peak at 7680 watts

This is all a pretty good match for high loads and hillclimbing.

chuck

 

[jawnn]

If 12 volts will not power my delta trike with two stages: 3.5” to 12” pulleys then 17 to 30 sprockets = 12.23mph at 1066 rpm motor speed, (with 500lbs on a long 10% grade? if that will help?)

Then I am just going to have to build a Rocket Trike and run it with 24 volts at 20-25 mph.

Note that this trike is too long and heavy to flip over forward. The seat should be set at 40 degrees or use a seat belt for emergency stops. It also needs a fairing wrapped under the crank to keep the feet from being mangled by being dragged under the front bar. But most importantly it needs a good rear brake or two. Unfortunatly there is no good rear brake made for bicycles.

I can’t use a motorcycle wheel unless there is a jack axle to tie in the pedal powered system. Also the motorcycle wheels are way too heavy, this machine must be kept down to 250lbs.

So maybe I could use a covered motorcycle disc brake on a bicycle wheel?

Bicycle drum brakes are not for stopping, only a drag brake for tandems.

http://wildnaturesolutions.com/rockettrike.html

 

[chuck]

Jawnn,
12 volts will power the bike at the speeds and hills you want to ride.
It is the amp hours you listed above that is lacking at 12 volts

A 12 volt 60 amp hour battery will supply the same power and range as a 24 volt 30 amp hour battery and a 36 volt 20 amp hour battery.

A 3.5 inch 3vx belt driver pulley on a 2 stage reduction at 1066 rpm will not work. These drives must be engineered. If a parameter is changed, then the whole drive must be re designed. To use a 2 stage drive at 12 volts will require me to spend about an hour to design. An hour I do not have right now. I suspect that the drive will be inefficient and extremely expensive.

What is expensive? The drive could end up costing over a thousand dollars. I like to keep the efficiency of drives above 90 %. To spend over a thousand dollars and have a drive that is 70 % efficient just does not make economic sense to me. The ineffiency of the drive will require a larger battery, and possibly a larger motor and a larger controller. Then the overall cost could be over 2000 dollars for a 2 stage drive at 12 volts. For a 2 stage drive at 12 volts driver pulley on the motor will increase in size, the driven on the jackshaft will increase in size.. You may not have room for these changes.

You listed several parameters that I am designing around.
The 3.5 inch 3vx motor driven sprocket will only work at 24 volts with the 909 motor with a lifepo4 30 amp hour battery minimum.
The 3.5 inch 3vx motor driven sprocket will not work on 12 volts or with 36 volts with the parameters I am using.

Hell of a lot cheaper to go to a bearing supplier an get a longer 20 mm axle shaft, use a 72 tooth wheel sprocket and a 17 tooth motor driver. Lot easier too.
only one drive to align. only one drive to adjust the tension on. The battery will have half as many cells as a 24 volt motor. Easier to mount. Easier to charge. Easier to balance.

Re think all of your parameters using all of the information I have given you.
Range (30 miles)
Speed (15 mph)
Weight (maximum 600 lbs)
Maximum grade and the distance of this grade. (16%)
Budget (?????)
Vehicle (?????)
Charging capability (In town)
Required charge time (????)
Your fabrication abilities and tools (????)
Fill in the blanks, help me get on the same page as you are on, then lets stay on the same page.

Chuck





I

 

[jawnn]

Forget the budget, it’s not possible. Forget the delta trikes also not possible.

Speed: 20 mph unless impossible or just not sensible….

I can build any thing with hand tools, unless I can afford to have some one else do it.

I need to compare the 12-volt and the 24-volt systems.

12volt: No need for belts or pulleys = More efficiency.
Slower hill climbing?

24volt: Same amount of batterys.
More gear reduction = less efficiency?
Faster hill climbing?

Is a fourth 12v 20ah battery needed for 20mph cruzing at any speed?

Grade: less than 100ft of 16% or around 300 ft of 9%.
Too bad I can’t just use a Nuvinci gear hub.

 

[jawnn]

I wish some one would take all this info and turn it into a book called “the dummies guide to designing an e trike”.

It would need to simplify the math with calculator keys so that I could just find what I need and punch it in.

But don’t expect me to under stand it.

 

[chuck]

Jawnn,

You said forget the budget,,,does this mean unlimited budget, or, a thousand dollars is not enough?
Forget the delta trikes? Does this mean you are building a tadpole, or you will electrify your current delta?

12 volts vs 24 volts. With the 909 motor. About 30 feet/sec, up a 10% grade,,20 mph
(.1 x 600 lbs x 30 ft/s)/550 = about 3.5 hp (Including wind resistance and rolling resistance)
3.5 hp x 746 watts/hp = 2600 watts.
70% efficiency. = 3700 watts from the battery

At 12 volts the battery current will be about = 3700/12 = 300 amps
The batteries, the motor, the controller, can all supply this for 300 feet pretty easily, oh, you might slow down a little, a few mph,
300 feet/30 feet/sec = 10 seconds
10 seconds is a blink of an eye to the entire electrical system. 300 amps is 5c. 10c is the max short term current rating. the 12 volt 60 amp hour battery can handle short bursts of 600 amps per the specs.

At 24 volts, and a 30 amp hour battery the current in the same scenario will be 150 amps. This is still 5c as far as the battery is concerned, both the motor and the controller can handle this as well. Again, you might slow down a little. maybe a couple of mph.

Jawnn, when I give you a scenario, that set of specifications of battery, motor, controller, and drivetrain is for that scenario only.

12 volts will work. 24 volts will work, 36 volts will work, 100 volts will work.

The alltrax controller I suggested will work on your present delta trike.

At twelve volts, the thundersky 12 volt 60 amp hour battery, the 909 motor, the 17 tooth and 72 tooth sprocket will work, as a system. It will fly up that hill at 15 mph. I designed it to. To go 20 mph up that hill will require a slightly larger drive sprocket which I have not calculated yet. Maybe a 22 or 23 tooth, I have not calculated the 20 mph drivetrain.

I want to help you Jawnn, this is pretty easy stuff for me. I need all of the information to do a proper job. Please list everything. I made a list just a couple of posts ago. Fill out everything again. List clearly what you envision.

Maximum range required, Nail it down, if you say 20 miles, you will be at 80% discharged at 20 miles.
Maximum Weight. don't guess, this is important. if it is really 700 lbs, then I have to know this
Maximum slope, measure it, and measure its length, don't guess. 200 feet of slope is a couple of residential lots. Measure it, Google it. I need to know.
Desired cruising velocity. If you want 16.5 mph, I need to know this. Brushed electric motors demand PERFECT gear ratio's to be efficient.
The time needed to charge. One hour is very, very unrealistic. 2 hours is unrealistic. 3 hours is barely adequate. 4 or 5 hours would be nice.
Where you plan to charge. 220 volts, 110 volts, 15 amp service, 20 amp service. Will other appliances be using this circuit, or only the charger.
The vehicle you plan to electrify, Its drive wheel circumference or diameter, this must be accurate.

TO EMPHASIZE THE ABOVE
Any system consisting of a motor, controller, battery and drivetrain that I design will do what I say it will do. It will do what you want it to do. If any of the above six parameters change, then I, the designer, cannot be responsible.

If you say 20 mph I will design the complete system to be driven at 20 mph. You will need a speedometer. You may not exceed this speed. The vehicle will travel about 25 mph. Does'nt matter, the motor will be very ineficient running 25% over its design rpm. Extremely inefficient. Your range will plummet. Probably by more than half.

THIS IS WHY I MUST HAVE ALL OF THE PARAMETERS.
And then you will be stuck with those parameters. Make sure they are accurate, finalize your needs, live within the restraints we have discussed.
Only then can I design a properly functioning system.

Jawnn, I know I sound harsh, I don't mean too. I do mean to emphasize the importance of accurate data to design a system that is long lived and trouble free. And will meet your expectations. And do this at a reasonable cost.

chuck

 

[jawnn]

The delta trike motorization is obviously s hopeless case, please forget it.

Money? I can’t think about money…. its going to cost at least 3 thousand dollars, just be reasonable….I need this machine to work, not a cheap short cut that will be un-efficient and burn out.

People are telling me that I must be crazy to spend so much effort to build this machine. And I do feel a bit “nuts” about it, but I think they must be insane to under design their machines. Like the ‘rocket trike’ builder refuses to think about it, he just uses the large 45hp e-tek motor at 48volts because it has the torque need to climb our hills at 25 mph with inadequate gear reduction.

The primary reason I thought of changing it to 20-25mph is simple that most people cant even think about moving as slow as 15 to 20mph, and it does seem a bit slow for the trike that I now know that I must build, like it or not. For my delta trike it seemed right, but that trike is impossible to motorize unless I do as these dummies say and use a motor that you have proven not be worth a darn. Like the “stoke monkey” or some lawn mower engine…. As I said these people are not thinking.

I will settle for 15-20 if you tell me that it is the only reasonable thing to do, and tell me what is the top speed that 12 volts will do. are you saying that climbing the hills at 20mpm or a little less is perfectly possible? amazing.

But I do need an explanation of why people tell that 36 to 48 volts systems are the only efficient way to go. Actually it appears to me that the 12 volt system is the only way to get really good efficiency (amazing to me), which will really upset all these people. But I knew for a long time that they didn’t really know what they were talking about.

Maybe I should just try a small hub motor on the delta trike and see if it's a waste of money?

The hub motor I need would be a high torque 2 hp at 200 rpms? And may need a zero point module to run it. Because it would hang out the back and use the chain to to the axle, reducing the efficiency rather than the speed.

 

[jawnn]

How fast is it possible to charge a battery? Will 50% charging be faster than 80%..or is it that last little bit now matter how much the battery has? What kind of circuit do I need?

 

[chuck]

Jawnn,
The 909 motor will give you the power you need at 12 volts. The 12 volt 60 amp hour thundersky battery will give you the power you need. The alltrax controller will give you the power you need.
I do not know what other people are telling you, can you link me to these discussions? The 909 motor at 36 volts would be about 3 times the power that you would need.
Do I think a hub motor would work on your trike. It would help. On the steep hills I do not think it would have enough traction to do much.

Remember, The power comes from the battery. Power = volt x amps.
12 volts x 100 amps = 24 volts x 50 amps = 36 volts x 33.3 amps = 48 volts x 25 amps. All of these are equivalent to 1200 watts.
The 909 motor is rated for 100 amps continous, with bursts up to 300 amps.
I am not familiar with any hub motor that could accept that much current continuosly. I think most bicycle hub motors are rated around 20 to 30 amps, therefore to get power out of them they are run at higher voltages.
The larger the amperage, the larger the wire must be.
On bicycles, it is kind of hard to get three 2 gauge wires through the hollow axle to power the hub. That would be the main reason lower voltage hub motors are not very powerful, there is no effective way to make the axle large enough for the power wires.

I do not want to get into a discussion on motor windings, blah blah blah,
A hub motor on the front wheel of your trike would really help on the flats. I think you need about 250 watts to go 15 mph on the flats.

From my reading here on the forum, the nine continents motor is pretty highly rated. It probably would not have the power to propel 600 lbs up your hills at any speed without overheating, even with pedal assist. Secondly, without plenty of weight on the front wheel, the motor would lose traction. The controller would either shutdown from current overload or overheat on steep hills.

I am doing the following math in my head, no calculator. this is not the final solution for the battery.
You said you wanted about 30 miles of range at 15 mph. Including the inefficiencies, and a 20% reserve, we need about a kilowatt hour of energy. To provide the current necessary for hill climbing we need about the same kilowatt hour of battery. A twelve volt 60 amp hour thundersky battery is about .75 kilowatt hours of energy. At 30 miles, this battery would be dead. At 24 miles this battery would be 80% discharged.

You want to charge this battery fast. OK. The thundersky specifications say max charge current is 3c. 3 x 60 amps is 180 amps. At 13.6 volts. Lets see here. That is 2448 watts. Let us use a charger that is 70% efficient. We need an outlet to plug this charger in that can handle 3500 watts. A 110 volt outlet would need to be able to supply 32 amps. Your battery charger cables to the battery would need to be about 3/4 of an inch thick, each, to handle this much current efficiently. You would be able to charge your batteries in about 20 minutes. This charger would not be portable, would be custom made, probably about $1000 to $2000 from Lester, Japler schaur, Schumacher. Second, about the most you can pull from a 110 volt circuit wired with 12 gauge romex containing a 20 amp breaker is less that 20 amps. Or the breaker blows.

The reality is, you will be fortunate to find a 110 volt outlet that will supply about 10 amps.
Even at this 1000 watt level, only 700 watts is available to the batteries. Means you will charge in about an hour, with no battery balancing. Kind of dangerous. You will need 4 gauge battery cables to handle the charging current of 50 to 60 amps. The wire will be warm, the connectors, even 100 amp rated anderson connectors, will get very hot. Oh, and remember, forget about battery balancing.

High charge rates are not condusive to long battery life unless you are very well versed in battery management.

A two hour charge rate is about 25 to 30 amps. 50 amp rated anderson connectors will get very hot at this rate. Forget about battery balancing. But you will probably be able to find a charger in the 500 dollar range. Not a portable charger. But it will be a smart charger with the lifepo4 charging scheme.

4 hours is really a much more managable charging regime. Still a fast charge time, realistically, for a large battery like this.

I looked at the rocket trike, bad center of gravity, centered directly over the front wheels, hell yea, that bike could flip, easily.

As to speed, on your current delta, 15 mph max, in my opinion.

chuck

 

[jawnn]

So the higher voltages are more efficient because of the battery’s low ability to release amperage fast enough?

How efficient is the old e-tek at 48 volts compared to 12 volts? Does it depend on the wires, batteries and amount of gears?

If hub motors must use high voltage, the only way to have enough high torque (low rpm) is for them to use planetary gears, and thereby reducing the efficiency?
How efficient is the best hub gearless hub motor?

000000000000000000000000000000000000000000000000000000

My land lord has a solar power shop and knows something about charging batterys, and wanted a clarification on the 3c definition: “is 3c one third of the amp hour rate or 3 times?”

He is also thinking that it would be good to use some sort of pulse charger at a trickle. But that would probably limit my travel in the winter.

000000000000000000000000000000000000000000000000000000

The rocket trike’s cog is not on the front axle, you forgot to add the weight of the batteries and motor and cargo etc.

 

[chuck]

So the higher voltages are more efficient because of the battery’s low ability to release amperage fast enough?

No, higher voltages are not more efficient. 12 volts x 100 amps is 1200 watts. Watts is power. 24 volts x 50 amps is 1200 watts. There is no efficiency gain or loss by changing the voltage. On series wound motors, changing the voltage changes the speed of the motor. More poles slows the speed of the motor. More windings per pole decreases the speed of the motor.

How efficient is the old e-tek at 48 volts compared to 12 volts? Does it depend on the wires, batteries and amount of gears?

It is just as efficient. At 12 volts it will run at 1/4 of the rpm that it has at 48 volts. It will put out 1/4 of the watts that it will put at 48 volts. It will use the same size wire, the wire rated at slightly higher than the motors continous amperage rating. The gear ratio is specific to a set of data, for a particular vehicle, as discussed previously..

If hub motors must use high voltage, the only way to have enough high torque (low rpm) is for them to use planetary gears, and thereby reducing the efficiency?
How efficient is the best hub gearless hub motor?

No, the rpm can be reduced by increasing the number of windings, and, increasing the number of poles. Stronger magnets will also slow the rpm. As a system, well designed, about the most you should expect is about 70 to 80% from any controller,motor and drivetrain combination to transfer the energy of the battery to the pavement.

Jawnn,
Try to not think in terms of torque.
Try to understand efficiency from a different standpoint.

A quality brushed permanent magnet motor such as the Etek, or the Mars 909, have peak efficiencies of around 88%. The reality is because of varying loads, hills etc, the peak efficiency is never reached.

A quality brushless motor is 3 phase, again, about 88% efficient. A three phase motor is smaller, not more efficient. Oh, hell, about 1 or 2% more efficient. The problem is, the controller is less efficient, kinda balancing the equation. A three phase motor, because of phase sharing of amperage, can use smaller wire per phase. Overall, you may expect better efficiency with a 3 phase motor and controller by paying quite a bit more money for the system, for a very small, if even measurable, increase in efficiency.

Brushed motor controllers such as the alltrax, are bulletproof. I once worked with a lot of industrial variable speed 3 phase drives, usually around 440 volts, I personally have never came across a controller for 3 phase that was bulletproof.

From an economic standpoint, spend the money on more batteries, much more efficient use of your money.

My land lord has a solar power shop and knows something about charging batterys, and wanted a clarification on the 3c definition

Most batteries are rated in amp hours.
So for a 60 amp hour battery.
The c rating of the battery explains its maximum discharge rate. And its maximum recharge rate.
The thundersky is rated 2c discharge. 2c x 60 amp hour rating is = to 120 amps discharge current.
The thundersky is rated 3c recharge. 3c x 60 amp hour rating is = to 180 amps charge current

chuck

 

[jawnn]

Speed: 20mph

Range : 12 miles round trip, this is the short trip.

Total rise on the road: 280 ft say 600’ round trip

Grade: one hill has about 500ft of 2.7” rise over 24”

Weight: about 100lbs plus batterys and motor plus 350 for the cargo (me etc.)

Drive wheel and tires: 100 psi 2” wide

The long trip is much shorter than I thought. only 16 miles round trip and about 800 ft total rise. two steep hills but I don't think they arer as steep as the ones in town.

 

[chuck]

distance, 12 miles x 5280 feet = 63360 feet
weight, 520 pounds
Maximum slope, 2.7/24 = .1125
Net change in elevation, 280 feet
estimated frontal area, 5 square feet, still do not know what vehicle.
estimated coefficient of rolling resistance, .0055
velocity, 20mph x 88/60 = 29.3 feet/second

The forces,
rolling, 520 pounds x .0055 = 2.86 pounds
air resistance, .5 x (5) x (.9) x (.0023) x (29.3)^2 = 4.44 pounds

Total energy required for a round trip, force x distance = energy
(2.86 + 4.44) x 63360 = 462528 ftlbs = 174 watt hours

efficiency factor, .7
174/.7 = 248 watt hours

safety factor, .8, maximum battery discharge
248/.8 = 310 watt hours.
12 volt system, 310/12 = 26 amp hour
24 volt system, 310/24 = 13 amp hour

Maximum current, hill climbing, no acceleration
.1125 x 520 pounds = 58.5 pounds
(58.5 + 2.86 + 4.44) x 29.3 = 1928 foot pounds/sec
1928/550 = 3.5 hp
3.5 x 746 = 2611 watts

2611/.7 = 3730 watts, the watts the battery sees.

3730/12 = 300 amps
3730/ 24 = 150 amps

You will need four quality lifepo4 30 amp hour cells for 12 volts, absolute miminum
Or, eight 15 amp hour quality lifepo4 amp hour cells for 24 volts, absolute minimum
Thundersky cells are available in 20, 40, 60, 160, or 200 amp hour sizes.

I would suggest the four thundersky 40 amp hours cells, run this system at 12 volts for ease of charging.
Alltrax 2444 controller
Mars 909 motor.

Cannot calculate a reduction ratio, no wheel diameter or circumference has been given.

 

[chuck]

Jawnn,
The weak link in the above scenario is the battery size. I am not comfortable running a battery at its maximum c rating. Connectors get dirty, increasing their resistance, resistance creates heat, then you blow a battery terminal. Throw the battery away. It is trash. As amp hour capacity increase, so does the size of the battery terminals.

Under batteries and chargers, what appears to be a pretty good charger, "dash power". All your wire and wiring accessories too.
http://www.powerwerx.com/

For a 12 mile round trip, 280 foot change in elevation, the average current calculation, uphill.

distance, 6 miles = 31680 feet
rise, 280 feet
slope, 280/31680 = .0088
weight, 520 pounds
velocity, 29.3 feet/second
rolling and air resistance, 7.3 pounds

force of the slope, .0088 x 520 = 4.58 pounds
(4.58 + 7.3) x 29.3 = 348 ftlbs/sec
348/550 = .63 hp
.63 x 746 = 470 watts

efficiency factor .7
470/.7 = 671 watts, the power the battery is releasing,

current, nominal
12 volts, 671/12 = 55 amps
24 volts, 671/24 = 28 amps

As you can see, we are very near the 2c continous rating using batteries that will supply the 12 mile range.

The batteries that supply the proper range are being run very near their continous rating, and at times run at very near their maximum 10c rating.

Throw in some wind, a good 20 mph headwind. Then the batteries are way past their continous and their maximum current rating.

Your desire to go from 15 mph to 20 mph will require the same 60 amp hour, preferably larger, thundersky batteries. With a reduction in range.

The conclusion, .....
I would recommend a delta, light motorcycle rear wheels, standard handle bar steering, for a 20 mph trike.

chuck

 

[chuck]

Jawnn,
Re-reading some of your musings on previous posts. You feel that it is incredible that you could build a trike that goes up steep hills at 20 mph. It is not incredible, it is very doable. With absolutely no pedaling, ever.

For the loads and hills you encounter, a 12 volt system at 20 mph using the 909 motor, alltrax controller and 60 amp hour thundersky batteries should be adequate. I say should be, I do not know what vehicle you are planning to build. To keep cost and complexity down, 12 volts allows us to use a single reduction drive. 12 volts allows the use of a single charger, and fewer cells to monitor and balance. This is itself a 2 to 3 hundred dollar savings.

Stability.
A tadpole is a very complex vehicle. A delta is a very simple vehicle.
You feel that a tadpole is more stable.
I say horse apples.
Take a piece of paper.
Draw a large circle.
Draw a capital T on the circle. The pillar of the t parallel with and on the line of the circle.
The T represents a delta or a tadpole trike.
There is a point in the center of the circle. Draw an arrow starting from the center of the circle right thru the center of your T.
That arrow represents the force. Centrifigal force. It is 90 degrees from your direction of travel.
Centrifigal force wants to tip your trike over, wether it is a delta or a tadpole.
To make a delta more stable, the seat is put near the rear wheels which act as outrunners, hopefully the rear wheels will resist the centrifigal force.
To make a tadpole more stable, the seat is put near the front wheels, the front wheels being the outrunners, hopefully the front wheels will resist the centrifigal force.

A tadpole, unless very carefully designed, is a much more unstable vehicle.
Hard braking, it tips forward because the center of gravity is so far forward.
uneven front brakes, cause it to readily go into a spin.

If you expect a tadpole to handle better than a delta, I hope to dash those expectations.
You may hear a lot of good things about tadpoles, but they are not talking about the vehicle you envision, and the forces on your vehicle.
20 mph and near 600 lbs. Your forces from turning and from braking are very large, 4, 5, 6, 7, 8 times the forces from a pedal powered tadpole with a 120 pound operator.
Unless you can engineer around the shortcomings of a pedal powered tadpole, you would be much safer with a delta.

From an engineering and design view, build a delta.

chuck