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[protomech]

Farasis produces the cells used in the 2013 Zero. Brammo also switched to Farasis cells for their Empulse RR racebike at Indy this year.

I recall looking for the datasheets at launch without success.

CDI sells the Farasis 25 Ah cells (say that 5x fast), though they do not list the prices directly. Interestingly, they also provide a datasheet (PDF)!

(Maybe this is only news to me, but w/e)

Compared to the EIG C020 20Ah cells (PDF) used in the 2012 bikes, the Farasis cells are slightly denser - both weight and volume - and claim slightly less power density, 7C @ 10s vs EIG 10+C. (which is fine.. even the smaller ZF8.5 bike can provide 52 kW of power for 10s).

Zero appears to run the cells slightly harder than that - they would need to pull about 10C from the cells to get 20 kW for the ZF2.8 bikes and 40 kW for the ZF5.7 MX.

Similarly, Brammo will need to pull pretty hard from the cells to get the power they need racing. Figure 130 kW @ 14 kWh = pretty close to 10C as well.

Farasis also produces 18650 cells, but they don't appear especially noteworthy @ 2400 mAh max. Samsung sells 2900 mAh cells, and Panasonic's 3100 and 3400 mAh cells (slightly lower voltage) are similar to those used for the Tesla Model S.

[grindz145]

This is AWESOME info! Thanks! It's really useful to help us (the RIT EV Team) gauge exactly how much more power density we'll need to meet our power targets, considering we're using Zero drivetrain.

[ReverseTrike]

Hi protomech,
This is very good information for people like me working on other designs using but will be using Zero's powertrain.
I am an aero and not an electric  so I am trying to educate myself as much as I can and would appreciate you response to my questions,
1. The Size 6 Sevcon allows the 75-5 motor to go to 73HP but looks like the limiting duration of 10 seconds for that power(besides cooling) is the ZF8.5 battery pack. What happens to the battery power draw duration when you go to ZF11.4, does it stay at 10 seconds or increases and if so by how much under the assumption that the motor cooling is adequate?
2. I need to run the motor for a few minutes at it's maximum power but also want the flexibility of the removable battery pack so can I hook up four battery packs together to get to the ZF11.4 storage without using it's battery pack?

Thanks

Farasis produces the cells used in the 2013 Zero. Brammo also switched to Farasis cells for their Empulse RR racebike at Indy this year.

I recall looking for the datasheets at launch without success.

CDI sells the Farasis 25 Ah cells (say that 5x fast), though they do not list the prices directly. Interestingly, they also provide a datasheet (PDF)!

(Maybe this is only news to me, but w/e)

Compared to the EIG C020 20Ah cells (PDF) used in the 2012 bikes, the Farasis cells are slightly denser - both weight and volume - and claim slightly less power density, 7C @ 10s vs EIG 10+C. (which is fine.. even the smaller ZF8.5 bike can provide 52 kW of power for 10s).

Zero appears to run the cells slightly harder than that - they would need to pull about 10C from the cells to get 20 kW for the ZF2.8 bikes and 40 kW for the ZF5.7 MX.

Similarly, Brammo will need to pull pretty hard from the cells to get the power they need racing. Figure 130 kW @ 14 kWh = pretty close to 10C as well.

Farasis also produces 18650 cells, but they don't appear especially noteworthy @ 2400 mAh max. Samsung sells 2900 mAh cells, and Panasonic's 3100 and 3400 mAh cells (slightly lower voltage) are similar to those used for the Tesla Model S.

[protomech]

73 hp = 54 kW, that's around a 6C draw from the 10 kWh battery.

Farasis rates the cells at 10s 7C or continuous 4C. I would guess maybe 30-60s at steady 6C? Keep in mind for an aero application that battery voltage will sag more as the battery discharges, at 25% energy remaining you're going to pull harder on the batteries.

Brammo appears to be happy with the cells in their racing applications, but unlike aero they're not going to be running at maximum power for all but a small portion of the time. Still, they've got to be putting some stress on them..

I don't see why you wouldn't be able to run four or more modules in parallel, which would effectively be a ZF11.4 pack. Zero does do some funky things to allow mixed-SOC packs to be used together, I don't know if that would cause complications.

Of course, the best thing would be to get a few cell samples and see how they actually perform. Datasheet power claims especially are somewhat loose at best.

[zlagger]

Good info, thanks!

[NoiseBoy]

Sounds like you are doing a top speed run reversetrike so do you actually need to be lugging 11.4KWh around?  Sounds like something higher density like LiPo built with 40C+ packs would do the job better, although I appreciate that weight isnt much of an issue for you, it would take up alot less space so you could make it smaller to improve frontal surface area and you could slot small packs all over the bike in different places so they are easier to cool and you can place them to move weight around and maximise stability.

[ReverseTrike]

Noiseboy, sad for me as all your recommendations are true but let me give you my side of the story.
1. I am an aero guy and not electrical and want a complete plug and play system that is off the shelf and the Zero gets me that at a very good price point.
2. I am already trying to balance out all the things needed for the trike and powertrain is one of the things that can make or break the performance of this thing. I really do not want to reinvent the wheel and make new mistakes and learn and rework. I already have a lot on my plate. Time is of essence and so is money!
3. The flexibility that I get with zero battery pack (removable, waterproof, stackable, start with one and then add, BMS build in, proven...etc ) can not be achieved by me. Is there something else available that I can use off the shelf  that can replace the Zero battery with 40C+ off the shelf available pack? and how will it work with the existing Zero motor, the controller etc, I really do not know!
4. Frontal surface area is not the right measure of the drag, it is the equivalent flat plate area. It even includes the cooling drag(for ICE installed vehicles). I can make a very large shape almost approaching an RV with the drag of that is less that that of a Cessna aircraft. Actually there is no magic to that. A slender frontal area normally does give you (as a good starting point) low drag but there is so much that can be done beyond that.
5. My other interest is to use the Zero powertrain for aviation like the eGull except that the implementation is for a two seater and requires about 70HP minimum for take off and climb out for 3 minutes. The added advantage is that the removable Zero  battery pack (being the most expensive part of the powertrain) can be installed in the trike or the aircraft depending on your recreational use for the day. If you want I can point out atleast 10 mission critical advantages that electric powertrain brings to GA, I have been waiting for this for a long time and I think we are very close so I am trying to solve the puzzle.

I am still at the design phase as I want to indulge when I have all the parts in place and understand how they come together and their limitations.

All the posters here have helped me learn so much and I continue to do that still. Please keep your comments coming. I hope to start a new thread in the not so distant future on my build; gathering ammo now 

Sounds like you are doing a top speed run reversetrike so do you actually need to be lugging 11.4KWh around?  Sounds like something higher density like LiPo built with 40C+ packs would do the job better, although I appreciate that weight isnt much of an issue for you, it would take up alot less space so you could make it smaller to improve frontal surface area and you could slot small packs all over the bike in different places so they are easier to cool and you can place them to move weight around and maximise stability.

[zap mc]

Great Work
Protomech! Thanks 

looking at  the spec at 3.65V nominal to 4.2V max this is close to the Molicel.
Does anyone think we could reverse engineer the old molicel battery pack with these?

[protomech]

Sure. They *might* be a little low on power, esp for an X bike.

eyeinthesky provided length/height dimensions for the XU battery pack here:
http://electricmotorcycleforum.com/boards/index.php?topic=3237.0

If you stand the Farasis cells on their side, they are 161mm = 6.3" tall so would probably fit.

They are 240mm long including tabs = 9.5" long. That leaves approximately 6" of space behind for BMS and wiring.

At 6.0 mm thick, 14 cells stacked across the width of the enclosure would be 98mm = 3.9", 28 cells would be 196mm = 7.7".

14 cells would be 1.28 kWh, 10s power 9 kW.

28 cells would be 2.56 kWh, 10s power 18 kW. Should be close to stock, but about 50% more energy and probably a little lighter.

[zap mc]

do they have an approved method of joining?
wondering if you could emulate the molicel setup and use the same BMS?  2x4.2V together with a bus bar top and bottom which is connected in series to make 58.8V?

[trikester]

The added advantage is that the removable Zero  battery pack (being the most expensive part of the powertrain) can be installed in the trike or the aircraft depending on your recreational use for the day.

I've been enjoying the fact that I can now swap batteries between my custom "reverse" trike and my FX. It has worked out to be handy sometimes. Usually one set is fully charged, if the other is not.

Also, some postings back the Zero 11.4 pack was mentioned and questioned to build one using the 2.7 modules. That is how Zero does build the 11.4 pack, so it's definitely do-able.

Trikester

[WindRider]

Hey Trikester, have you ever considered a rack to carry another ZF power pack above the rear fender of your FX for more range?  It looks like it would fit nicely there but would some mass that is terribly high for handling.   

[trikester]

Hey Trikester, have you ever considered a rack to carry another ZF power pack above the rear fender of your FX for more range?  It looks like it would fit nicely there but would some mass that is terribly high for handling.   

I have only considered that for the e-trike where it would not have so much effect on the handling and would actually help rear wheel traction. Unfortunately, the stock Yamaha rack, that is on the trike now, is only rated for 7 pounds. So it would require some serious mods before I could even try it.

Trikester