Possible battery pack, other equipement?

Just2807

10 W
Joined
Jun 20, 2015
Messages
68
Location
Croatia
Hello to all! been reading this forum for almost a year, my 1st post here.
Short and simple:
I will be able to get pouches very cheap (3.3V 20aH, lifepo4 i think) around 20 pieces. Always wanted to convert dirtbike into street/cruise commuting bike. Got couple of chassis around which i can get cheap.
Goal:
~100 km/h max speed
~60-70 km range ("eco" driving, terrain combined)
-99% asphalt
Good performance/range ratio.

Question:
Possible? (willing to extend pouche number for range sake)
48-60-72 V?
Hub or non-hub?
Bldc or AC?
Geared or non geared? (regarding max speed)

Transmission, controller etc etc will be dictated by battery pack and chosen motor (looking for 15-20 kW max, cca 10 continuous).

Tone of info in here, similar specs, different results.... 2 many questions. Would appreciate if u narrow down my point of research and pointed what's the best "configuration" for me. Just rough pointers.
Love this forum, greetings from Croatia!
 
For such speed and power a 3000W (rated) non geared BLDC Hub will work close to your specs at >72V

You know which frame you are going to use?

You will need a really big space for such batteries. (x3 the volume of Li-ion / LiPo)
 
Not sure which pouches will be available, there are 15Ah and 20Ah versions, ill get specs as soon as possible (maybe bms available with them). Got spec from older pouches (nanophosphate) we have used but these are newer, not sure maybe different. That's why i wrote they will dictate the rest of equipment.
As far as i can remember, they were under 0.5 kg for sure and were able of higher discharges (again, spec soon).
So 3 kW can actually get me uphill, desired top speed on flat road with bike over 100 kg and my self 75 kg ?
Got several frames on "junk", from yamaha dt to honda hornet 600cc, will be picked best space/weight ratio needed. Doesn't necessary need to be enduro/cross.
Just looking at pointers to "calculate" and pick (or narrow down) everything when i collect info.
Will be glad to post progress and ask advices here when i start the project.
I study for electrical engineer but i have 0 experience with it (couple of house installations, nothing deep or complicated), been in Formula Student for a few years, sadly wasn't working on electrical/electronical department so when i see what u people doing here, really gets me going!
Will post asap.
Also, just asking from experienced people, is it the same (heating/overheating motor, not controller) to use 3kw to the "max" and using lets say 5 kW and "locking it" on 3kW? Is heat dissipation the same since there are different windings and probably different copper thickness?
 
Probably the most flexible design would be a chain drive motor. BLDC would be best in 99.% of the cases, however, the exception is the Agni 95 brushed DC. 16KW motor With peaks to 30kw. Extremely high efficiency, beating most BLDC or AC motors, and the flexibility to change gear ratios for tuning.

But It's still hard to say whether that motor will work with those cells.
 
Found out pouches are nanoposphate chemistry working at 3.3V each with 20Ah. A guy said it has high C number but he wasn't sure exactly how much (he is the middle man).
I am fairly interested with agni model 95 (saietta?). Since i wasn't looking at brushes as an option and this motor really looks good (at least on paper), could pouches work with it? Or should i just go for cylinders?
 
If this guy didn't mix something up, 25C cont, 50C burst but don't know for how long. I could get them for free that's why i am asking about them. Anyways thx, ill check out brushed motor reviews on forum.
 
But that agni motor can only handle about 200ah cont. And 400ah peak. Those cells are overkill and you would only be able to draw 10c cont. 20c max. You wont be using them to their potential but free is free. Might want to set up a few in parallel to get longer range. 20ah wont last but 10-15minutes roughly at 200ah draw
 
Hm y, kinda wasted...

Been thinking, will go on "torque bike", probably costume built frame (this will be a huge pack o_O) like a lot of users here since e motorcycle needs much more investment than i thought. Since 80% of my country is hilly, is there any other good option (motor) accept famous kits (bbs, cyclone...) for my "uphill" needs? Mid drive ofc. Basically, would like to go on top, and enjoy downhill but in recreational style (cruising everywhere without being in top shape), not performance mode if u get my point. Also, roads here go up and down all the freaking time. Some slow wind(?) motor which could get me 35-40 km/h on straight but keep me for a while uphill? (a weekend, vacation, freetime fun bike)

Regarding batteries, yes, they are free and there are around 25-30 pouches which should cover 40Ah at 36V or maybe even @48V.

Every day i am learning something new here, can't follow up everything o_O
 
You'll want more than 1.3KWh for a moto you intend to take to 100kph and ride up hills. Build it anyway with the free batteries, and you'll probably be motivated to extend the range after seeing how kickass your ride is.
 
Nah, gave up on moto for 1st build, maybe better for start is Vector/Stealth (30-40km, cca 40-50 km/h) style bike, since batteries are free, it will be 50% cheaper. I can also get wheels and frame pretty cheap. I should stay with mid drive right? That should be more efficient rather than hub's, especially for hills?
Or some cool 7 speed hub came out in the meantime? :D
 
Well, it all depends. How much do you weigh? How steep are the hills, and how long are they? These are all critical factors.

On a bike, the big advantage of mid drive other than gears, which may not matter unless you have rather steep, or rather long hills, is you won't have a ton of unsprung weight on your rear wheel. It screws up the bike's handling if you plan to ride at the limits or on low traction surfaces (off road). Now, my ebay 1KW running 4KW max input power takes me up hills with no problem, although I only weigh 130 lbs. It also goes 70KPH topped out with me in a tuck although that really eats battery. If you're OK with only 40-50KPH top speed, you can get a hub wound with fewer KV than mine and it should put you in the sweet spot on hills. I'm running 79v peak for 70KPH with my winding. The big advantage of a hub is cost, ease of setup, and lack of required engineering / fabrication.

How do you plan to setup your mid drive? The real problem with mid drive is it's much, much more complicated to set up than a hub motor which is more or less plug and play.
 
Basically, in my hometown, there isn't much problem, "short" hills and i can manage to go tops without being in top shape.
But, weekends and vacations i am mostly on an island (all our islands are "hilly", most tops are 400-800 m, very steep), and got around 20 km when i leave the ferry to the house. Ofc tarmac roads are acceptable. And lots of gravel over the leveled top. Awesome gravel tracks to by the whole island coast. Ill pin few images so u can see for yourself.

http://www.citypictures.org/data/media/197/Port_of_Jelsa_Hvar_Island_Croatia.jpg
http://www.villa-tamara.com/wp-content/uploads/2012/12/Zavala-Island-Hvar-panorama1.jpg

For an example, on 2nd link, this gravel track from sea to top is about 8-9 km, height is around 500-550 m. 100 km long island and zillion tracks available.

I am 70 kg's (around 160 lbs?), don't need mad 100 km/h tarmac rush, just good help going up. I like downhillers but not the mad ones, just like to be pulled by gravity, nothing extreme.
Wasn't even considering hubs since high amp and low rev would probably get them hot pretty quick pretty fast and couldn't control rpm for best effective range. Maybe some slow wind torquey... Still don't dig them yet for climbing.
And yes, setup will be 48V+
 
Yeah, you want a mid drive with variable gearing to climb hills like that for sure! Looks like a nice place.
 
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