Battery pack size for electric motorcycle moped?

[Sym]

Hi, I am planning on building an electric motorcycle that was originally a moped. It isn't very heavy at around 100lbs with the engine. I'm planning on using a 3kw-5kw goldenmotor at 48v. I would like to go around 40-50mph so the motor should take care of that. I need help deciding what size battery pack size I would need in terms of Ah to get me 35-40 miles. I am also a very light person at 114lbs because I am 17. Should I use SLAs to start or go right to lithium/lipo4

I am trying to make my own version of the Bolt M1 without paying $6000 https://s-media-cache-ak0.pinimg.com/736x/0c/27/ba/0c27ba0c467ba123d06eeba856ae5ffd.jpg

 

[diff_lock]

Go 18650 lithium right from the start. Build it yourself or source one from the forums or online store.

At 40 mph expect to use 70+ Wh/mile. 40 mile range = 40 miles x 70 Wh/mile = 2800 Wh then divide by .75 since you don't want to fully discharge your pack and you get 2800 / .75 = 3700 Wh aka 3.7 kWh. This will be a 44 lbs battery.

Other cell options:
http://hybridautocenter.com/HAC4/index.php?option=com_hikashop&view=category&layout=listing&Itemid=605

 

[Sym]

Go 18650 lithium right from the start. Build it yourself or source one from the forums or online store.

At 40 mph expect to use 70+ Wh/mile. 40 mile range = 40 miles x 70 Wh/mile = 2800 Wh then divide by .75 since you don't want to fully discharge your pack and you get 2800 / .75 = 3700 Wh aka 3.7 kWh. This will be a 44 lbs battery.

Other cell options:
http://hybridautocenter.com/HAC4/index.php?option=com_hikashop&view=category&layout=listing&Itemid=605

How far do you think I'd be able to go with 20ah or 30ah. Distance isn't really something I need as I just want this to get around places and I probably won't travel 40 miles in a day

 

[diff_lock]

Ah does not measure capacity. Wh is a measure of energy capacity.

Going fast is expensive. either spend money on energy storage or spend money or weight reduction and aerodynamics.

 

[agniusm]

Couple post down i rebuild electricmoto blade for my brother. Its 75kg, my brother is 65kg. With 2.5kW battery he done 42km combined off road/on road (more off road). I would say 3kW would do you 70km on road distance. I have used nissan leaf cells and they are joy to build. You have a nice opening below the tank. If you have access to workshop and somehow know some welding you could fit all you need there. It will be cheaper and easier than 18650. I don't see these cells in larger packs for motorcycles to be viable option, too complicated and costly.

 

[Sym]

Couple post down i rebuild electricmoto blade for my brother. Its 75kg, my brother is 65kg. With 2.5kW battery he done 42km combined off road/on road (more off road). I would say 3kW would do you 70km on road distance. I have used nissan leaf cells and they are joy to build. You have a nice opening below the tank. If you have access to workshop and somehow know some welding you could fit all you need there. It will be cheaper and easier than 18650. I don't see these cells in larger packs for motorcycles to be viable option, too complicated and costly.

The issue is, I am not too proficient with welding or building batteries. I know it is a cheaper option but I don't think it's viable for me. I've looked up on how to do it but I just don't think I could do it because I'd have to balance all the batteries, put them all together in a pack then put them together and either find or build my own BMS. I really can't do that. Goldenmotor sells a 20Ah pack (.98 kwh) at 48v. With my conditions, how far could I go with that. I'd probably only be going 20-40 mph

 

[shadow]

Multistar Lipo packs

48v sucks though, i would go for at least 72v. Make sure you look at the KV of the motor to ensure that you will reach the desired top speed.

Additionally, if you go with a sine wave controller (Adaptto, Kelly KLS), which you should, you'll need to subtract 15-20% of your calculated top speed based on KV.

 

[Sym]

Multistar Lipo packs

48v sucks though, i would go for at least 72v. Make sure you look at the KV of the motor to ensure that you will reach the desired top speed.

Additionally, if you go with a sine wave controller (Adaptto, Kelly KLS), which you should, you'll need to subtract 15-20% of your calculated top speed based on KV.

http://insideevs.com/bolt-m-1-electric-bicycle-moped-motorcycle-thing/ I'm pretty much trying to make my own version of this, the Bolt M1. From what the article says, It uses a 5kw motor with a 33V 1.68 kwr battery at 300 amps. It has a top speed of 40mph and that's pretty much my target speed if not a little bit higher. I'm trying to keep this cheap-ish without it completely sucking so what should I do?

 

[shadow]

Yes i am familiar with the Bolt, but it's not a production bike so you don't want/need to go copying their specs. They are catering to the opposite type of person than you, a builder. I also maintain that a 100+lb vehicle should not be running 48v. Especially if it's pushing 300A, that's just a bad ratio on all accounts.

well where to start...

I think you need to start doing a bit more research and come up with some sort of budget for each major component (controller, charger, batteries, BMS, motor etc) as well as very specific goals for output power continuous, peak, voltage, mid drive vs hub motor, and battery pack size (how much space do you have?). For each individual topic you can get lots of help on here or research what is already posted, but if you are asking about an entire system then it's hard to give you a specific build list without making lots of assumptions about cost, power, etc.

Going 50mph will require a little north of 5kW output power (unless i stand corrected), so you want to pick a motor that is rated a little bit more than that continuous.
At 48v, going 50mph that would be around 100A continuous draw, but again i would look at doing a 72/96V system to lower your amp draw, wire guage etc, there are lots of benefits, you just have to build a bigger battery pack.

The Midi-E Adaptto would be well suited to this, but it's always nice to have a little higher power capability (Max-E) in case you get better batteries, motor etc. http://adaptto.com/Products/Controllers/

It all depends on the budget and overall goal, if you just want to make an electric moped and don't mind it going regular moped speeds, then targeting 5kW continuous output capability might be fine. Without some method of shifting (which i would not recommend), you will not have very much off the line torque if your top speed is 50mph and you don't have a very high peak output. I personally think 5kW is pretty boring, especially if you have decent forks and brakes on the bike. I built an 8kW output moped (made from a Batavus) a few years back and it was kinda cool but it did get old, now i'm more than doubling the output on my new build.

 

[Sym]

Yes i am familiar with the Bolt, but it's not a production bike so you don't want/need to go copying their specs. They are catering to the opposite type of person than you, a builder. I also maintain that a 100+lb vehicle should not be running 48v. Especially if it's pushing 300A, that's just a bad ratio on all accounts.

well where to start...

I think you need to start doing a bit more research and come up with some sort of budget for each major component (controller, charger, batteries, BMS, motor etc) as well as very specific goals for output power continuous, peak, voltage, mid drive vs hub motor, and battery pack size (how much space do you have?). For each individual topic you can get lots of help on here or research what is already posted, but if you are asking about an entire system then it's hard to give you a specific build list without making lots of assumptions about cost, power, etc.

Going 50mph will require a little north of 5kW output power (unless i stand corrected), so you want to pick a motor that is rated a little bit more than that continuous.
At 48v, going 50mph that would be around 100A continuous draw, but again i would look at doing a 72/96V system to lower your amp draw, wire guage etc, there are lots of benefits, you just have to build a bigger battery pack.

The Midi-E Adaptto would be well suited to this, but it's always nice to have a little higher power capability (Max-E) in case you get better batteries, motor etc. http://adaptto.com/Products/Controllers/

It all depends on the budget and overall goal, if you just want to make an electric moped and don't mind it going regular moped speeds, then targeting 5kW continuous output capability might be fine. Without some method of shifting (which i would not recommend), you will not have very much off the line torque if your top speed is 50mph and you don't have a very high peak output. I personally think 5kW is pretty boring, especially if you have decent forks and brakes on the bike. I built an 8kW output moped (made from a Batavus) a few years back and it was kinda cool but it did get old, now i'm more than doubling the output on my new build.

Honestly, 50mph isn't really something I even need. I just wanted to know what kind of things I would need to go that speed and work down from there to create a more manageable system based on that benchmark. I only really need to go around 35-40mph and I might implement a pedal system as I have seen pedal adapted to frames like this. My tech teacher even suggested it and have me a few ways to do it. So now that 48v is no longer really a suitable option, if I were to do say 72V on a 5Kw motor, what capacity pack would I be working with to go say even 25 miles? Size at this point isn't really a matter to be discussed. I really just want to know what kind of capacity is required.

Also, I don't really know of a hub motor that would be good for my purposes.

 

[shadow]

Honestly, 50mph isn't really something I even need. I just wanted to know what kind of things I would need to go that speed and work down from there to create a more manageable system based on that benchmark. I only really need to go around 35-40mph and I might implement a pedal system as I have seen pedal adapted to frames like this. My tech teacher even suggested it and have me a few ways to do it. So now that 48v is no longer really a suitable option, if I were to do say 72V on a 5Kw motor, what capacity pack would I be working with to go say even 25 miles? Size at this point isn't really a matter to be discussed. I really just want to know what kind of capacity is required.

Also, I don't really know of a hub motor that would be good for my purposes.

Hub motors of every size do exist...So that's always an option, frees up a lot of space in the middle of the bike and eliminates any need for a belt or chain, as well as adjusters. Both types have their pros/cons

25 miles at moderate speeds (30-40mph) can be done with a 2kWh pack quite easily, with some room at the bottom so as not to discharge the cells too far. Could you go farther on such a pack? Well yes, either by putting it on a bicycle (less weight) or driving at more efficient speeds, which you won't do because riding full speed will be awesome and you will never want to be going 25-35 when it is capable of more.

I wouldn't get too distracted with pedals, they are primarily added for legal purposes, i can assure you they are equally as useless as they are on a traditional moped. Humans simply don't generate enough power to make it worth a damn when you have a big battery pack onboard anyhow

 

[Sym]

Honestly, 50mph isn't really something I even need. I just wanted to know what kind of things I would need to go that speed and work down from there to create a more manageable system based on that benchmark. I only really need to go around 35-40mph and I might implement a pedal system as I have seen pedal adapted to frames like this. My tech teacher even suggested it and have me a few ways to do it. So now that 48v is no longer really a suitable option, if I were to do say 72V on a 5Kw motor, what capacity pack would I be working with to go say even 25 miles? Size at this point isn't really a matter to be discussed. I really just want to know what kind of capacity is required.

Also, I don't really know of a hub motor that would be good for my purposes.

Hub motors of every size do exist...So that's always an option, frees up a lot of space in the middle of the bike and eliminates any need for a belt or chain, as well as adjusters. Both types have their pros/cons

25 miles at moderate speeds (30-40mph) can be done with a 2kWh pack quite easily, with some room at the bottom so as not to discharge the cells too far. Could you go farther on such a pack? Well yes, either by putting it on a bicycle (less weight) or driving at more efficient speeds, which you won't do because riding full speed will be awesome and you will never want to be going 25-35 when it is capable of more.

I wouldn't get too distracted with pedals, they are primarily added for legal purposes, i can assure you they are equally as useless as they are on a traditional moped. Humans simply don't generate enough power to make it worth a damn when you have a big battery pack onboard anyhow

The purpose of the pedals are really only for legal purposes so I don't have to register it as a motorcycle. There's no engine so there's no way to decipher whether it is a motorcycle or just a moped.

Also then, what hub motor would you recommend?

 

[shadow]

http://www.hs-escooter.com/sdp/1012764/4/pd-4958252/7980445-2261356/4000W_72V_10INCH_Brushless_hub_motor_for_e-scooter.html

http://www.alibaba.com/product-detail/120kph-max-speed-140N-M-torque_2006080193.html?spm=a2700.7724857.29.55.DwXSpa

http://www.alibaba.com/product-detail/8kw-Hub-Motor_60044084577.html?spm=a2700.7724838.30.11.1RK6mw


I mean there are plenty to choose from but you need some kinda target for the project to work off of.

 

[agniusm]

Multistar Lipo packs

48v sucks though, i would go for at least 72v. Make sure you look at the KV of the motor to ensure that you will reach the desired top speed.

Additionally, if you go with a sine wave controller (Adaptto, Kelly KLS), which you should, you'll need to subtract 15-20% of your calculated top speed based on KV.

Looks like you have no clue.

Whats the benefit 72v over 48v? Lipo packs, really?

 

[Sym]

Multistar Lipo packs

48v sucks though, i would go for at least 72v. Make sure you look at the KV of the motor to ensure that you will reach the desired top speed.

Additionally, if you go with a sine wave controller (Adaptto, Kelly KLS), which you should, you'll need to subtract 15-20% of your calculated top speed based on KV.

Looks like you have no clue.

Whats the benefit 72v over 48v? Lipo packs, really?

So.. Should I do 48v? I'm trying to save cost. I don't necessarily need this to be perfect right off the line..

 

[agniusm]

High voltage does not have any benefit other that get electrocuted. Motors could be wound to any speed pn given voltage. Its more simple to work on lower voltage system. Less wiring. At the end, power is power, no matter what combinatio.
Hub motor will save you space and fabrication but if you will need to adjust speed there is no easy way. 2 choices, hub motor will need to be rewound or you will need to up the voltage.
Mid drive is easy, you only change the sprocket.
If I was certain on top speed I will need, I would go with a hub motor, 48v wound for desired speed.

http://www.hs-escooter.com/sdp/1012...-bike_Spoke_Hub_Motor_150mm_width_for_th.html

You can customize voltage and speed for this motor.

 

[Sym]

High voltage does not have any benefit other that get electrocuted. Motors could be wound to any speed pn given voltage. Its more simple to work on lower voltage system. Less wiring. At the end, power is power, no matter what combinatio.
Hub motor will save you space and fabrication but if you will need to adjust speed there is no easy way. 2 choices, hub motor will need to be rewound or you will need to up the voltage.
Mid drive is easy, you only change the sprocket.
If I was certain on top speed I will need, I would go with a hub motor, 48v wound for desired speed.

http://www.hs-escooter.com/sdp/1012...-bike_Spoke_Hub_Motor_150mm_width_for_th.html

You can customize voltage and speed for this motor.

Are you sure 3kw is enough for my uses? this thing will be 200+ pounds which includes me

 

[diff_lock]

3kw is nominal. Peaks can be 2-3x if your battery and controller can support. Temp sensor on motor copper + ferofluid in hub motors and you can dump a lot of current into a motor. Of course there are electromagnetic limits too.

 

[shadow]

if you want low voltage low power stuff i would start in this forum

https://endless-sphere.com/forums/viewforum.php?f=3

 

[Sym]

3kw is nominal. Peaks can be 2-3x if your battery and controller can support. Temp sensor on motor copper + ferofluid in hub motors and you can dump a lot of current into a motor. Of course there are electromagnetic limits too.

I'm sorry to keep this thread going on for so long but I just want to get all the information I can. I suppose the motor has been situated, I just need to decide between hub or mid drive and the controller shouldn't be too hard to find on my own. Attaching pedals for legal reasons shouldn't be too hard but now I'm still sort of stuck on the battery. Don't get me wrong, I love building and doing electronics but I cannot stress enough how much I don't want to build an 18650 pack. Not a chance. Nor will I ever build one out of those flat lipo cells. The only things I will ever consider are building a pack out of hobby king cells (A good guide on that would be nice) and just buying a pre-made battery pack. Based on everyone's responses and my own budget, I want to stay within 20-30Ah. Lets say more towards 20Ah as a starting pack because I may upgrade in the future.

Are there any easier ways to build a pack that don't require testing and balancing of individual cells and stuff. I really just a self contained e bike with charger that can just be plugged in. Are there any simpler methods as to doing this? I know of using those 4s-6s batteries but I am not too familiar with that. Most videos just present the fact that they built it and most forum posts I have found just do the same thing.

 

[shadow]

http://lunacycle.com/batteries/packs/

https://endless-sphere.com/forums/viewtopic.php?t=26383

There are a few available packs (for ebikes) that fall into the size category you are suggesting.

The lipo packs are a bit more flexible in that you can get damn near any combination of series cells and mAh. The multistars are pretty nice, been around for a while, good performance and very competitive cost/kWh. Well suited for ebikes up to bigger bikes. They come with XT90 connectors for power and JST for balancing, so you just have to create the other half of the wire harness and package the blocks together. There's no getting around having basic monitoring equipment for any successful EV project though, a smart balance charger, power supply, quality multimeter etc. With Lipo packs there is some initial testing to make sure all the cells are good and balanced, the fallout is potentially higher than with other sources but the lifespan can be very long when good healthy cells are treated properly and sized adequately for the application.

Start looking at different combinations of charger/battery/controller/motor that are compatible to get a sense for the final cost, then go for what makes sense. IMO building a 3kW output moped is just an overweight ebike. Might be slightly cheaper i guess

 

[Sym]

http://lunacycle.com/batteries/packs/

https://endless-sphere.com/forums/viewtopic.php?t=26383

There are a few available packs (for ebikes) that fall into the size category you are suggesting.

The lipo packs are a bit more flexible in that you can get damn near any combination of series cells and mAh. The multistars are pretty nice, been around for a while, good performance and very competitive cost/kWh. Well suited for ebikes up to bigger bikes. They come with XT90 connectors for power and JST for balancing, so you just have to create the other half of the wire harness and package the blocks together. There's no getting around having basic monitoring equipment for any successful EV project though, a smart balance charger, power supply, quality multimeter etc. With Lipo packs there is some initial testing to make sure all the cells are good and balanced, the fallout is potentially higher than with other sources but the lifespan can be very long when good healthy cells are treated properly and sized adequately for the application.

Start looking at different combinations of charger/battery/controller/motor that are compatible to get a sense for the final cost, then go for what makes sense. IMO building a 3kW output moped is just an overweight ebike. Might be slightly cheaper i guess

I think I want to go with the multistar ones. What combination of packs would be good? like a few 5000mah ones or what? Sorry for my lack of knowledge on batteries. I just want to make this as efficient as possible.

 

[Sym]

http://lunacycle.com/batteries/packs/

https://endless-sphere.com/forums/viewtopic.php?t=26383

There are a few available packs (for ebikes) that fall into the size category you are suggesting.

The lipo packs are a bit more flexible in that you can get damn near any combination of series cells and mAh. The multistars are pretty nice, been around for a while, good performance and very competitive cost/kWh. Well suited for ebikes up to bigger bikes. They come with XT90 connectors for power and JST for balancing, so you just have to create the other half of the wire harness and package the blocks together. There's no getting around having basic monitoring equipment for any successful EV project though, a smart balance charger, power supply, quality multimeter etc. With Lipo packs there is some initial testing to make sure all the cells are good and balanced, the fallout is potentially higher than with other sources but the lifespan can be very long when good healthy cells are treated properly and sized adequately for the application.

Start looking at different combinations of charger/battery/controller/motor that are compatible to get a sense for the final cost, then go for what makes sense. IMO building a 3kW output moped is just an overweight ebike. Might be slightly cheaper i guess

I think I want to go with the multistar ones. What combination of packs would be good? like a few 5000mah ones maybe a fwe 10000mah ones or what? I do understand how to achieve proper voltage and and capacity by parallel and series but I'd just like to know what you would do. Sorry for my lack of knowledge on batteries. I just want to make this as efficient as possible.

 

[agniusm]

Get this one: http://hybridautocenter.com/HAC4/in...ery-modules-60ah-58-8v-nissan-leaf&Itemid=605
Only bms to wire and you will have 3kw of usable energy. You could ask someone to make you aluminium box to fit them.
Lipo is dangerous, unreliable and cycle count is low.
Leaf cells work out a lot cheaper per mileage.