DIY Aptera knockoff?

[Gordo]

Here is the graph from Caleb on the 70Ah cells;


Local guys have been abusing the TS cells for years. Charging them to 4.1V and running at 2C. No failures so far, except for cells that have been killed by a shorted out BMS.

Some interesting puff from Mt. Chen;
"Dear EV Pioneer:
Merry Christmas & Happy New Year !
Our company just get 30% investment from the best Lithium battery manufacturer.
So that we will self-confidently claim 8 years warranty or 50000kms on battery if you buy our high performance electric scooter equipment with CHL lithium battery and Active BMS. This would be the world record in field of EV.

CHL lithium battery are set up in 2010 target for Kinglong E-bus supply and we use high performance materials which could bear 6C constant discharged current and temperature are never raised more than 10 degree during discharging because of 0.16mΩ (ohm) low impedance.

Our life cycle testing with 1c charged and discharged is around 1916cycle with only 30% capacity reduced,so that 8 years with 400 deep cycle charging every year would be definitely not problem.see attached data.

Active BMS would be another revolution in field of EV,our active BMS uses electromagnetism inductance principle for moving excessive charge of one cell to nearby not so full cell.

This can work both during charging as well as discharging, and only limited to 1A or 2A small currents.

The system is called active BMS or inductive BMS that uses cable to transfer higher currents between cells, in contrast to the usual "passive PCM balancers" who just simple "burn off" excessive charge of
cells by heat resistance. Which might cause potential fire incident too."

 

[Hillhater]

Are you suggesting we ignore the manufacturers recommendations ( 0.3C discharge ) ?
Its obvious these cells are able to output a much higher current, but I suspect there is a good reason they have such a low continuous rating, otherwise they would exploit a higher rate in the advertising.

 

[Gordo]

No, look at the Caleb manufacturer's chart I posted for this cell, which clearly shows 21A & 70A graphs. Last time I did my gazintaz 0.3 X 70A still came out to 21A. I agree 0.3 X 70 = 18 in OZ but please leave the civilized world in their ignorance. :lol:
As I posted, there are dozens of EV's running around here on TS cells and according to the armchair doomsayers, daily abusing the heck out of them by overcharging voltage and overdrawing current. They believe and have proven over the years that discharging below 2.8V greatly shortens the cell life, but overcharging to 4.1V and pulling 2-3C for less than 5 minutes at a time, does not. Long term theoretical use dictates having enough Ah to make the trip and stay above 3V. But after you have spent $20K on a vehicle and can't make it to work and back, topping it up to 4.1V as you have breakfast allows you to make the trip without flattening your pack. Seem like a reasonable solution to me, until you can save the cash to add some cells.

As far as the "knockoff" goes, I give the guy huge credit. He spent years and $$$ building something that he is satisfied with. All on his own, without deep pockets. He started with lead and has now sunk a large amount into Li. I'm a lot more interested in what he has done and will do in the future, than criticizing the speed or distance at speed. We can all do the math and factor in hills and headwinds and call it a looser by our standards, but why Many guys here have accomplished a lot more or a lot less. So what Last time I looked the competition was to build something that worked, not something better than the next guy I glad the guy is not a member, reading this negative drivel.

 

[Hillhater]

Actually that 18A figure came straight from the " lithiumstorage.com" page ( a USA site i believe ?)
Maybe they know something we dont ? :lol:
http://lithiumstorage.com/index.php?main_page=product_info&cPath=&products_id=10&zenid=7b379bb45801e1eab7ee31b5c51da7cb
Criticism, sometimes is necessary to point out the shortcomings of a design, in order to improve upon it.
It may be true to state the Wind is a 60 mph (max) vehicle, but unrealistic for anyone to think that is a practical speed for anything other than a "burst" situation. It would be more useful to quote a realistic "cruise" speed .. (25mph ?)
And i still dont think we should give the idea that you can use a battery beyond the manufacturers recommendations and expect it to last or perform without problems.
If i am going to invest several thousand in a battery pack, i want to think it is going to last its planned life and not fail because of abuse.
Again i ask, ...why do they recommend a 0.3C continuous discharge. ???
The last time i looked ... this thread was about finding something that would replicate the Aptera, ! .. the Wind does not do that in its current form.

 

[jmygann]

.
The last time i looked ... this thread was about finding something that would replicate the Aptera, ! .. the Wind does not do that in its current form.

what does ?? other than photoshop and auto cad

 

[Hillhater]

From page 3 of this thread..

I thought the thread was about replicating an " Aptera" type vehicle ! ?
I dont think the Aptera had any pretensions of being anything less than a EV " car replacement" for regular practical use.
You wont be able to do that with any superlight, un licienced, unregulated, vehicle.

This is why i said someone should define the basic requirements, or this thread will simply be a dumping space for every daydream in our heads.

and Harold posted the most detailed spec..

If anyone is seriously interested in starting this project, here are some specs to begin the figures and start up budget. I have been away from the States, and, have no access to supplies, but, I know places in S Florida I used to deal with.

Dimensions:
53" high x 91.0" wide x 173" long
111" wheelbase
80.5" front track.

Other specs:
0.15 Coefficient of drag
5" ground clearance
1500 lbs curb wt.

Electric motor torque: 60FtLb torque
110v 15A charge time: 8 hrs.
Battery output: 10-13 KWh battery pack.
Battery voltage: 336V DC Nominal Traction Voltage
Transmission: Gear box 10:1 ratio
Battery Type: Lithium Iron Phosphate

Chassis:
Front Suspension: Independent unequal length A-arm
Rear Suspension: Swing Arm
Steering: Manual Steering, tilt steering column
Brakes: Manual Brakes, dual circuit brake hydraulics, mechanical brake proportioning, 3-wheel disc
Wheels: 14-inch High Strength Stamped Steel wheels
Size: P165/65R14

Performance:
Range: Up to 100 miles per charge.......

a few others seemed to concur that "highway speeds" ( 60+mph ?) would be a target also.
Generally it should be a practical, everyday, EV substitute for a small car !

 

[Gordo]

Actually that 18A figure came straight from the " lithiumstorage.com" page ( a USA site i believe ?)
Maybe they know something we dont ? :lol:
http://lithiumstorage.com/index.php?main_page=product_info&cPath=&products_id=10&zenid=7b379bb45801e1eab7ee31b5c51da7cb

Again, no, you are wrong. The 18A figure is either a typo, or Oz math. Check the figures on 40,60,70,...400.
The recommended continuous draw is 0.3C X the Ah of the cell, except for the typo on the 70Ah cell. The chemistry in all the cells is the same regardless of the capacity. Carefully read the graphs for each size of cell and note the numbers at the top. Turn on your thinker while reading

 

[Hillhater]

So i copied their typo ! ..what is the big deal ?... 18 A..21A..
..either way it is less than the 22A he was drawing at 25mph...

..and do you think the 0.3C rating is simply a random number,.. or just maybe the result of some extensive testing by the manufacturer !

 

[Gordo]

There is no big deal. Now you understand the numbers, carry on criticizing from a better informed position.
:lol:

 

[leffex]

Found a video on a veichle, didnt find it posted so here it goes
http://www.youtube.com/watch?v=lxGCGZLqfEs&feature=related


Translogic 74 - Amp Electric ATV

new off-roader

 

[Toshi]

what is an ATV legally? In EU its a motorcycle... Or cant you register an ATV for road use?

If you are going to make it bike legal with pedals, that means 15-20mph and 200-250-750-1000 watts max too. Subject to lots of varying regulation. Not much of a vehicle.

These posts raise an important, and mostly overlooked-in-this-thread, point: Whatever is built must comply with relevant US regulations in order to be both legal and relevant. (I'm being US-centric here and assuming we're the still the market that counts.)

As I see it, there are several major classes of vehicles of varying street-legality:

1) Low speed electric bicycles. The Federal limits are 750 W and 20 mph top speed, and most states adhere to this definition. Some allow for slightly more power (e.g. 1 kW) and Florida is the outlier by far, allowing 5 kW and 60 mph (!) top speed. Given that they only carry one person and the vast majority of states limit the vehicle to 20 mph and 750 W, I don't see how an e-bike, e-trike, or e-velomobile in this class could potentially even be considered as an Aptera substitute.

2) Low speed vehicles/medium speed vehicles. I refer the reader to the linked thread, in which I look at the relevant laws, etc. The gist of it is that Low Speed Vehicles, which are electric by definition, are limited to 25 mph top speed in the majority of states, and aren't even legal at all in some states. A handful of states allow for 35 mph operation but no commercial products to fit this niche exist. This is a potential category where an Aptera clone would fit, but then one must shoot for a lower price point. On the upside, 4 wheels are legal in this category, and that'd make engineering much simpler.

(Or one could just spring for a Polaris EV LSV and call it a day.)

3) ATVs. As I found out through my own research detailed on Google+, ATVs are not street legal in almost every state. A few Western states are the exception, sure, namely Wyoming, Montana, Idaho, and Utah. Therefore a street legal ATV-classed product wouldn't be commercially viable and this category is a non-starter.

4) "Motorcycles" that really aren't. To start with, let's define what a motorcycle is. This varies a bit by state, but in Washington it's as follows:

"Motorcycle" means a motor vehicle designed to travel on not more than three wheels in contact with the ground, on which the driver:

(1) Rides on a seat or saddle and the motor vehicle is designed to be steered with a handlebar; or

(2) Rides on a seat in a partially or completely enclosed seating area that is equipped with safety belts and the motor vehicle is designed to be steered with a steering wheel.

"Motorcycle" excludes a farm tractor, a power wheelchair, an electric personal assistive mobility device, a motorized foot scooter, an electric-assisted bicycle, and a moped.

Note the "not more than three wheels in contact with the ground" and requirement for either a handlebar or an enclosed seating area + steering wheel + belted seats. This is the legal grey zone that Aptera hoped to exploit.

5) Full fledged cars. "Real cars" need to meet the NHTSA's Federal Motor Vehicle Safety Standards, of which there are a metric shit-ton. Read 'em here. I don't think meeting them is a practical goal for a homebrew project unless one starts from the shell of an existing, licensed and registered, vehicle. That idea, in turn, seems like a bad idea because most cars are quite heavy beasts indeed.

Here are TD's stated goals for this proposed vehicle:

I also reckon for the sake of the discussion, that concepts emulating Aptera design goals are fair game: roadworthy, four-season, stylish, high efficiency and advanced technology.

I will add practicality to the list: If an octogenarian can't easily get themselves in & out, or if it can't carry two people and a week's worth of their groceries, it's off my list.

The only ways to do this are approaches 4 and 5, of pseudo-motorcycles and full-fledged cars. I'll wager that it's not possible for a private builder to replicate the capabilities of, say, a Nissan Leaf for under, say, 75% of the Leaf's MSRP - tax credit, so that leaves just pseudo-motorcycles as the default. (I picked 75% arbitrarily, as I'd certainly spring an extra 33% for a warranty, local dealer support, etc. There has to be some incentive to doing it "off the grid," as it were.)

This means that all 4 wheel designs should be off the table, as they're neither here (4 wheels precludes classification as a motorcycle) nor there (full-fledged cars meeting all FMVSS regs or LSVs), IMO.

 

[Harold in CR]

We will soon find out. I read they are presently being built in China.

Link

 

[Grinhill]

Here's a three-wheeler being made by an Aussie light aircraft manufacturer. It looks a lot closer to the Aptera stylistically than some of the others posted on this thread. Sounds like they are serious about making it, have done moulds for the body etc, they are taking expressions of interest at this stage.

http://www.lightwing.com.au/roadie.html

 

[salty9]

It's what I want. hope they don't want too much for it.

 

[Hillhater]

nice, but a long time in the making ?.....

"The Roadie" is currently Under Construction at the Hughes Factory.
As of the end of 2008, we believe we are the only company to be seriously designing and developing a light electric vehicle in Australia.

And.. like any other EV maker wanting to actually achieve a 200km range and 100km/hr speed,...they will need a large ,heavy , expensive ,..battery pack. I am guessing, but probably at least in the 20kWhr range ?.. which would have to be in the 150+kg weight bracket.
This will be another expensive vehicle !

 

[Gordo]

http://greatgreenideas.wordpress.com/

roadie

 

[Hillhater]

http://greatgreenideas.wordpress.com/..

Hmmm. So, still no prototype ?

 

[hillzofvalp]

I think they kept the same safety precautions as an airplane. Lots of crumple zones .