Opinions on these ebike kits.

yes, this is a great way to get your feet wet. i think you need higher volts for the build. there are other experienced ebikers here too so post your plans before buying so we can confirm.
 
yes, this is a great way to get your feet wet. i think you need higher volts for the build. there are other experienced ebikers here too so post your plans before buying so we can confirm.
From what I just recently found out; two 18650 cells gives you about a mile of fully charged travel. Somebody told me, or I read that one amp hour is about the same. Most of my knowledge of electricity comes from what I can remember from computer tech class in high school and automotive electric in college. Now Tesla uses these cells; about 73/4 in each battery pack for their cars. I saw a youtube video where an ePorsche had I *think* 16 of them and used I believe two forklift motors. Wieght is not an issue with me, I'm not really looking at running 55/60mph consistantly. Just trying to figure out what roughly would yield about a 20mile.range at about 35mph cruising speed and maybe 40 or so flat out. I started looking at a youtuber called ebikeschool, he made a 2wd ebike and said both controllers had to be used and something about making sure the motors sync up by using a device that conmects rhem to the throttle and one sorta piggybacks off the other.
 
Just trying to figure out how much battery(and cells within) I would need, I came up with this.
-A single 18650 is 3.7v with 3400 mAh

-1000milliamps equals 1 amp

-Supposedly 1aH gives one mile of fully charged travel.

A single battery composed of 10 of these celks should be about 37v with 34,000 mAh.

Two of them working together is 74v giving 68,000 mAh's or 68aH's. Keeping it simple 68aH should be, by what I can figure is 68mi of travel at a consistant Xmph. This is what I have so far. I don't math.

The batteries will be powering(unless one controller could truely suffice) two 1000w controllers running 48v/1000w motors. If I'm right; tbese two motors will be seeing 68amps which I have no clue how many volts that is, since every calculator wants volts amps and watts, whivh is stupid.If I knew all that, I wouldn't need a calculator tobtell me how many watts make a volt or whatever.
 
- Better to think of batteries in term of watt-hour or Wh
- Two 36V 3.4Ah battery packs in series is 72V 3.4Ah not 6.8Ah but both are 122 Wh of energy
- Look up YT videos on how to properly make a battery pack. I would recommend buying one first, setup the bike, ride it for a while and after you learn more about batteries then make a pack. At this moment, I don't think you should make your own pack
- Use this calculator to determine your minimal voltage and power motor requirements. Note, this is minimal and you should get the next power level to be safe.
http://www.electricbikesimulator.com/calculator.php?language=en#
- To go a top speed of 35 mph, you will need 1500W. To be safe you should plan for a 2000W motor.
- Using same parameters above, for a 20 mile range you will need 830 Wh battery pack but you should plan for 1000 Wh+
- Depending on the battery grade, you might have a negative amp draw to capacity curve. Meaning if you draw high amps, you capacity goes down say 25-35% of rated. This is why you should try to get a higher voltage system or very good batteries
- I do not like duo 1000W motors. It is unnecessarily complicated especially with two controllers you will have so many wires your brain will explode. Get a single rear hub or mid drive motor based on the calculator determinations (remember to go next level up)
 
I know ebikeschool from YT. He is good and great instructor, but to do what you want you need to be on another level. His videos are good for introduction and LEGAL ebike builders (<= 750W). Your needs is on the level of the 2000W to 30000W ebike builders.

I like watching those high power ebike builders videos but I won't be building one any time soon. I am more looking to build and innovate in the legal (<= 750W) ebike space. But, of course everyone loves to see that 20kW speed burst and riders cursing and having their brains blown off assuming they don't fry their controllers.
 
I don't think we have ebike restrictions, and I can keep it at a slow pace and hit it if need be. I'm okay with wiring stuff up like two motors, it's pretty easy. Starting with one is a good idea, though.
 
Take a look at the high power ebikes on YouTube. Like they are pretty much all one big rear hub 1500W+. Unless you cannot get one of these 1500W+ kits then I would start working with a 1000W and overvolt it. But, if you can get one of the 1500W+ I would get a 2000W or something. Take a closer look on YouTube for high speed ebikes.
 
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