A rookies first build

D

Daanpassie

1 mW
Joined
Dec 1, 2020
Messages
14
Hi guys,

Due to an overflood of free time, I wanted to start a new project to keep me busy.
I've choosen for an E-bike/E-motorcycle which will have a cafe racer style. I'm a newbie to EV's so I need some help. I don't want to put a huge amount of money because it's just for fun and learning some electric basics.

The specs I'm try to realise are:
Range: about 25 miles
Top speed: 28 mph
Driving style: Mostly summer cruising, but I would like some nice accelerations.
Terrain: Flat ground( and some times a easy and light mountainbike trail)
Weight: About 285lbs(me included)
Max power: 4 kw continous (due to law regulations in my country)
Motor: mid-drive

I'm making the frame from scratch, so I can fit almost any dimension in the frame.
After doing some research I've figured out the following setup:

Motor:
https://aliexpress.com/item/4000976238582.html?spm=a2g0o.detail.1000060.2.6f035cbcUgrrAS&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.169870.0&scm_id=1007.13339.169870.0&scm-url=1007.13339.169870.0&pvid=b4c3c13c-fc65-4a85-8234-ed8ce96a263e&_t=gps-id:pcDetailBottomMoreThisSeller,scm-url:1007.13339.169870.0,pvid:b4c3c13c-fc65-4a85-8234-ed8ce96a263e,tpp_buckets:668%230%23131923%2345_668%23808%234094%23753_668%23888%233325%239_668%232846%238110%23332_668%232717%237566%23887_668%231000022185%231000066058%230_668%233468%2315607%2394

Controller:
https://aliexpress.com/item/4001049479645.html?src=google&albch=shopping&acnt=494-037-6276&isdl=y&slnk=&plac=&mtctp=&albbt=Gploogle_7_shopping&aff_atform=google&aff_short_key=UneMJZVf&&albagn=888888&albcp=6459818041&albag=78000837075&trgt=743612851114&crea=nl4001049479645&netw=u&device=c&albpg=743612851114&albpd=nl4001049479645&gclid=CjwKCAiA8Jf-BRB-EiwAWDtEGqcMOPtxQMsJO7B2gEL9hjRkJXV94QYzAY1zyQ9i6NZ-VheDDuxd5BoC2gMQAvD_BwE&gclsrc=aw.ds

Battery;
https://aliexpress.com/item/4001062046869.html?spm=a2g0z.12010612.8148356.10.403d5d65VqrNCt

My goal is to build a nice and sportive looking cafe racer, with some nice accelerations
I'm open to any suggestions, especially on the battery.

I hope I provide you guys with enough information to help and sorry for the grammar and spelling mistakes. English is not my native language.

Thanks in advance,
Daan
 
battery says 20 amp max continuous , thats 1000 watts

Battery Model:60V 20Ah
Nominal Capacity (AH) :20ah
Nominal Voltage (V): 60V
Cell Source Resistance (mΩ) :< 40 mΩ
Cell Specification :3.7V 18650 3400mAh 3C Powerful Cell
Cell Combination :6-parallel 16-series
Cell Quantity (parallel*series) :96 pcs
Discharge Cutoff Voltage (V) :48+/- 1V
Charge Cutoff Voltage (V) :67.2V
Maximum Continuous Discharge Current (A) :20A
Instantaneous Maximum Discharge Current (A): 60A
Charge Mode :CC/CV
Standard Charge Current (A) :2A
Charge Time under Standard Charge Current :10 hours
Max Fast Charge Current (A) :5A
Charge Time under Fast Charge Current: 4 hours
Charge Temperature Range :0-45°C
Discharge Temperature Range:-20-65°C
Battery Size :310*116*70mm
Battery Weight About:4.5kgs
 
I agree with the Goatman on this one. A 20 Amp continuous battery seems a bit low for your weight. Depending how you build your frame, your bike could reach around 100lbs after motor, battery, controller and everything else is attached. I would consider a higher continuous discharge battery then 20 amps.

:D :bolt:
 
Thanks guys voor the fast responds,
So I need a battery thats at least 45 Amps continous. And do you guys think 3kw is enough?
 
Ok, lets step back a moment. The controller, BMS and battery all have to be matched to work together.

The controller you posted is an 80A controller, that means if you want to use that one you need a battery and a bms that can handle 80 amps draw.
Controller Specs.JPG

Your controller specs also state that it can handle up to 2.5kv. So a 3kv motor is fine because it over your controller rating. Now all you need is a battery and bms that can handle your rated 80A current draw.

The battery you posted says it has a 20A continuous and 60A amp instantaneous maximum discharge, so it is not suitable for the motor and controller you posted.

BAttery specs.JPG

Keep looking for a battery that can handle something greater then 80A continuous discharge.

Also, start looking at the different discharge characteristics of different battery chemistry's. Not all lithium battery's are alike.

:D :bolt:
 
Thanks e-beach for your elborate explaination.
I indeed have read about some different kind of cella like 18650 or lipo4 and the C-rate.

Is it true that 18650 cells are better for this kind of use, because of there higher C-rate?

I also read somewhere that the amps of your BMS should be rated a X precentage higher than your battery. So should I get a BMS which is rated for 100 amps continous if my battery is 80 amps?
 
Daanpassie said:
Thanks e-beach for your elborate explaination.
I indeed have read about some different kind of cella like 18650 or lipo4 and the C-rate.

Is it true that 18650 cells are better for this kind of use, because of there higher C-rate?

I also read somewhere that the amps of your BMS should be rated a X precentage higher than your battery. So should I get a BMS which is rated for 100 amps continous if my battery is 80 amps?
Click to expand...
I run LiFepo4 batteries because they have a low volatility in case of puncture. I feel safe plugging my bike into the charger and going to sleep. However, they have a fairly low C rate and can sag upon acceleration. They are big and heavy however I prefer the feeling of safety they give me.

That being said, a lot of ebikes run on 18650 cells, and yes most of them have higher C-ratings then LiFepo4. Just be sure your battery pack is made of authentic cells and not Chinese knock-offs to insure a reliable battery. A 100 amp BMS would be better for a 80A draw because it is rated higher. If you push any electronic component to it's limit there is always chance for failure. Failure on an ebike battery could cause fire, so a higher rated BMS is a good idea.

:D :bolt:
 
Thanks man! You told me much stuff I didn't know. Do you know a good site where they sell reliable batteries and deliver in Europe?
 
If using 18650 cells they are all different some cells are 3-5amp for computers that seat on your table
and sitting still. Vape pipe cells are 20-30 amps and cost more. Samsang 25r 20amp or 30q 15 amp or Panasonic pf 10amp cell ECT ECT.
So how many amp draw is your controller and what motor ?
if a vendor won't tell you what cell he is using he is probably using a cheap generic Chinese cell .
How about a 3,000 Watt rear hub motor be and run at 5,000 Watt peak or 60amps.
Do you have the Donner bike yet as the parts must fit on the bike. Plan ahead
 
I don't want to use a hub motor, because I like te way a mid drive looks. I'm still looking for a good cell type, currently my preference goes out to lipo4 cells. My controller draws 80amps and my motor 45 amps continous so I'm looking for a battery pack which has max 80 amps continous.
 
LifePO4 is a very safe and long lasting chemistry for e-bikes, but it is also heavy. It's low energy density compared to other types of batteries means that the manufactures need to use a bigger and heaver size cell to have good performance. So, to match what you require for your build, a 60v 20 amp LiFePO4 battery is going to be very big and very heavy for an e-bike.

Just keep that in mind.

Have you looked at https://www.pingbattery.com/ ?

:D :bolt:
 
Thanks for the info.
Only the batteries at ping batteries are out of my budget? I would like to spend no more than 500 dollars for a battery
 
The battery is the heart of an e-bike. That is where the money should go. However, if you want to go for an inexpensive battery, then you are running a risk of fire. Those who want fast e-bikes often use RC Lipo batteries and find ways to charge them without setting ones house on fire. The 10C stuff has plenty of discharge current so no need to pay for the expensive stuff. For some reason I can't get onto Hobbyking.com at the moment, but that is where a lot of RC Lipo would get their batteries. Just learn how to use it, and make arrangements so that if you have a battery fire, you won't burn your house down.

First of all, an apology for just vanishing like that. I told the moderator crew what happened last February, but I was hesitant to talk all about it until I had money in hand. And I had quite a lot to do, with a good dose of PTSD.

The short version, my cheap ass shipped illegally 18650 48v 20 ah battery from K battery (alibabba) caught fire in my garage, while charging. https://endless-sphere.com/forums/viewtopic.php?t=87975
Click to expand...

Well, its been two years now since the fire, and I'm finally going to buy a battery.

I really got tempted to go back to lifepo4, and get another pingbattery. But the low discharge rate, heavy, and large size still turns me off.

I came to the conclusion that what type does not matter all that much, since no e bike battery is ever going to enter my house or garage again.https://endless-sphere.com/forums/viewtopic.php?t=99057
Click to expand...

:bolt:
 
I get what you mean and obvousily I don't want to burn my house down, but I can't find any good site where they sell 72v batteries with around 80 continous amps. But do I need to run my system at 72v? If no is the difference between 72v and 48v a lot, if you talk power?
 
Basically Volts = speed
Amps = Torque

It is not really completely that simple, but it is close enough to understand the concept.

A 48v 20ah system will get you 28mph should get you 30mph and go 25 miles, just not if you go WOT the whole way.

It depends on where you live. I live in a city with a lot of stop and go riding due to stop signs and stop lights. I average about 27 watts per mile. If you have long stretches where you don't have to stop, you should do better then that.

So a rule of thumb around here is 25 watt hours per mile .....so.

48v x 20 ah = 960 watts / 25 =38.4 miles.

Now that is all theoretical depending on all those things that effect the mileage of an EV, like riding style (fast / slow) wind, air temperature, hills, stop and go's, weight of rider and bike, tire pressure, aerodynamics, efficiency of the system, and I am sure more things then I can think of at the moment.

So yea, a 48v system could work for you but it will just be slower then a 72v system from things like a dead stop, going up a hill, or riding with a stiff headwind.

:D :bolt:
 
Ahh I got you! Than I think 48v is enough for me because I live in a small village with no stopping signs and nothing remotely close to hills.
So I think I will go for a 48v battery with a higher discharge rate, because I want some torque.
 
Daanpassie said:
Ahh I got you! Than I think 48v is enough for me because I live in a small village with no stopping signs and nothing remotely close to hills.
So I think I will go for a 48v battery with a higher discharge rate, because I want some torque.
Click to expand...

Why not buy the motor with the controller that is matched from the seller?:https://nl.aliexpress.com/item/32956364535.html?spm=a2g0o.detail.1000023.4.eedf7e33waqWJW
The motor has a maximum continuous amp input (heat dissipation) so a higher voltage at the same amp input gets you more power. Geared to reach the same max. top speed you'll get more torque at the rear wheel and thus better acceleration. The biggest problem will be the gearing as you'll need to get to a reduction of around 1:10 or more depending on the circumference of the rear tire.

BTW as you mention a max. top speed of 28mph (50km/u) due to regulations in (y)our country I think you have a hope of getting it road legal as a moped. That will be nearly impossible unless you'll be willing to pay much more for all the testing and certifications than the bike itself will cost...
 
I went for a different controller, because I've read on some threads on ES that was better. But I don't know if a programmable controller makes a use difference.
I didn't know that was that expensive to do, is there any way to make that less expensive, for example using a donor bike/moped and use that as foundation?
 
I have never paid more then $75.00 for any of my three bikes that I converted to e-bike builds.

:D :bolt:
 
That's more than doable, but I searched for my country the estimated amount is 1500 euros. So that is a lot, but then it's licensed as a E-scooter so maybe if I do it as an E-bike that is cheaper
 
Daanpassie said:
That's more than doable, but I searched for my country the estimated amount is 1500 euros. So that is a lot, but then it's licensed as a E-scooter so maybe if I do it as an E-bike that is cheaper
Click to expand...

Is that including the EMS/EMI (Electro Magnetic Susceptibility/Interference) testing? Or "just" the testing at the RDW? Don't forget you'll need to build with E-marked components (brakes, lights, etc.) and exactly to the L1 regulations/laws.
You'll end up with a bike/moped more expensive than a Super Soco (in our national colour, Willem would be proud :wink: ):
https://www.lasourisscooters.nl/super-soco/ts/oranje-adrenaline-orange

If you can be happy with customizing such a Super Soco to your liking, it would save a lot of time, trouble and money.
 
What a coincidence a fellow dutchie! I was talking about a normal test at RDW, but I found if I convert a existing moped, or anything else which is enlisted at the RDW, it way cheaper(around 150eu). So that's the best option for me, I think.
 
I highly doubt the conversion from ICE (Internal Combustion Engine) to electric propulsion will only cost €150,- to test and register. Yes for changing the ICE to another ICE or changes to the frame where just some paperwork and a visual check are needed. But again the EMS/EMI testing and certification will be the most costly part of the process. Although it might be less stringent then for a motorcycle conversion to EV.
 
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