100+ Miles of Fun per Charge: 5.1kWh batt, 20kw capable

Agreed. Keeping some safety margins helps reliability.
I am working on versions with 4115 fets and higher voltage caps and I am looking into the feasibility of using IRFP4568 as well for even better performance (and reliability).
Since these fets are rated for 150V, we should be able to comfortably push at least 130v.

John in CR said:
Of course there's a performance advantage using higher voltage, which is a different topic. The point I was making is that for a given rpm and torque a given motor gets the same signal from a controller regardless of pack voltage. It may be broken up into different size pulses due to pwm, but what the motor "sees" is a relatively constant supply. That means we don't get a benefit in the form of reduced I2R losses by using higher voltage for the same power. Yes, power input is volts X amps, but volts and amps have to be looked at separately...current for torque (acceleration/thrust) and voltage for rpm (speed, though there's a torque component with speed since the load of overcoming wind resistance increases geometrically.)

Regarding promoting the use of 100V limit equipment with packs that are 100V fresh off the charge, regardless of anecdotal evidence of people getting away with it, it should be discouraged. Those who get away with it are pushing light loads and use easy to drive motors, but even then failures are too common, and no one pushing real performance has gotten away with it without popping plenty of controllers. Since you're a vendor I'm trying to do you a favor. We've had only one vendor on ES who promoted the use of 24s packs with 100V limit components in the controllers, and he quickly went out of business. Absolute reliability is pretty easy even at extreme performance, and that is accomplished best by staying well away from current and voltage limits of any component in the system.

Powervelocity.com said:
If there is no benefit in higher voltage, we should be all getting 12v packs with 1000A discharge rates and be happy with all the torque we can get from it.
I will choose my 24s over 20s or 18s in a heartbeat, as the difference in performance is substantial.
And I have no concerns overheating my 18Fet controller running at 100v and 100Amps. The motor MXSUS v2, however, does overheat after 3 minutes running at 9kw but that's expected as that's 3x of its rated power.



John in CR said:
Using higher voltage to reduce I2R losses for the same power only applies between the battery and controller. Regardless of pack voltage for the same torque and rpm (power) the motor gets the same thing from the controller. Our controllers are buck converters to change the DC coming from the battery to exactly what our motor needs. I use higher than necessary voltage for a different reason than you plan, to get higher torque (greater acceleration) all the way through my usual top cruising speeds. That higher performance resulting from higher torque does have a cost in terms of more motor heat, but riding around using the same performance I would with a lower pack voltage has no cost in motor heat. There is more heat in the controller though, which warrants using a beefier controller like you plan. There's some interesting discussion on this topic here https://endless-sphere.com/forums/viewtopic.php?f=30&t=79229.
 
Oh yeah, plenty of margin. I thought you were talking about essentially a 72V controller with 100V components running at 100A.

Something to keep in mind on the 4115's is that they're much higher resistance means you need about double the fets to run the same current as with irfb4110's. I'm trying to get the controller factory I deal with to do up 12 and 18 fet controllers using irfp4468 and 4568 mosfets. They're already using them in the biggest scooter controllers, but for ebikes we need smaller cases, and the fets themselves don't require much extra room compared to 4110's and 4115's, so compact and big power is possible. Since my motors need 2 controllers, it makes compact and extreme power possible. :twisted:

Can't wait to hear your reports on the big battery. Eliminating range anxiety is so nice.

John
 
Yeah, I am yet to find a good route and a few hours of time to try to fully drain the pack and note the range, consumption, etc.

I am going to test compact 18Fet controllers with irfp4568 pretty soon
If it works well, it would be easy to come up with 6 and 12fet versions as well. We are talking about very good performance plus high voltage in a small package.

John in CR said:
Oh yeah, plenty of margin. I thought you were talking about essentially a 72V controller with 100V components running at 100A.

Something to keep in mind on the 4115's is that they're much higher resistance means you need about double the fets to run the same current as with irfb4110's. I'm trying to get the controller factory I deal with to do up 12 and 18 fet controllers using irfp4468 and 4568 mosfets. They're already using them in the biggest scooter controllers, but for ebikes we need smaller cases, and the fets themselves don't require much extra room compared to 4110's and 4115's, so compact and big power is possible. Since my motors need 2 controllers, it makes compact and extreme power possible. :twisted:

Can't wait to hear your reports on the big battery. Eliminating range anxiety is so nice.

John
 
What bms are you running ? Link, specs. 100 miles and plug into one of the new charging stations popping up over California. Wow opens the mind.
 
I have used Greentime for BMSes but I would highly NOT recommend them as they are such a royal pain in the butt to deal with. Chinese customer service at its worst. The quality sucks. They even admitted installing old fake FETs from the garbage bins on their BMSes when I got them in the corner by showing the pictures of the crap they sold. I can't understand how their business survives.

So, what I ended up doing is taking the boards, remove the crappy FETs they put there and install genuine good ones. No more overheating issues or deadly shorts.

http://www.aliexpress.com/store/product/20S-Li-ion-Lipo-Batteries-Protection-Board-BMS-System-72V-84V-80A-Continuous-Discharge-Current/313864_32500068377.html


999zip999 said:
What bms are you running ? Link, specs. 100 miles and plug into one of the new charging stations popping up over California. Wow opens the mind.
 
It was a great deal :), now there is a guy in Europe selling an EEB pack, using the new Sanyo cell, it's a 77v 33.5ah 21s10p pack delivered free!! for like 935 euros, of course that is in Europe, but I guess there is a revolution going on amongst pack builders lately. Viva la revolution :D
 
My back hurts thinking about riding 100 miles on an ebike, unless it is a recumbent.

Higher voltage is not saving any energy at all here. You lose far more in the 4115's greater resistance than you saved on the input wiring losses. The difference in temperature between a 4110 and a 4115 controller is substantial.

This is not about efficiency. It is big, heavy, and powerful. The higher voltage allows driving the motor harder, and at higher speed. That's what the higher voltage is about. Watch those motor and controller temperatures.

Ride safe.
 
It was and it still is if you do a bit of math.

33.5Ah times 77v makes 2,579 Wh which makes it half of the capacity of my pack (88v times 58Ah is 5,104Wh). Accounting for euro to dollar conversion rate, 935 euro for 2,579Wh is still more expensive than my pack per amount of energy. ;) I have also recently built a smaller pack with GAs for this frame for a customer build, 15p24s which makes 4,620Wh. I am yet to see anyone building or selling a pack with capacity anywhere closer to mine at a reasonable price or at any price for that matter. So far, it's been mostly 72v 20Ah or 30Ah at best. Heavy and bulky bricks taking all the space in the frame and giving like 20 miles of range.


ABritInNY said:
It was a great deal :), now there is a guy in Europe selling an EEB pack, using the new Sanyo cell, it's a 77v 33.5ah 21s10p pack delivered free!! for like 935 euros, of course that is in Europe, but I guess there is a revolution going on amongst pack builders lately. Viva la revolution :D
 
My back hurts from sitting in the office in one position for hours and I am dreaming of the time when I get home, hop on a bike and go for a ride. I do like from time to time to lift my butt off the saddle and pedal "recreationally". I see how this may work for miles and miles without too much damage to my back. I can't relate this to a recumbent experience as I don't have one, but, from purely theoretical standpoint, I may start feeling stiffness sooner in a recumbent on long distances as body movements are more limited. Just had a 50 mile ride on a bike with this battery over the past weekend. I can tell I get tired faster driving the same distance in a car.

I think the voltage vs. current topic has been beaten to death to this point. The bottom line is that some people are after higher speeds, some people are content with lower speeds. Right now, I am modding a controller for a customer that is planning to run 147v off the charge. Go figure. I feel like 88v nominal 100v fully charged is a sweet spot for a high performance bike and well suited for popular hub motors available on the market today. With 100v I can hit real speeds of 60 mph and above without engaging flux weakening and other tricks that kill efficiency further. 60mph is probably the highest practical limit for an ebike today (excluding racing application). Above that is the motorcycle territory where we would be talking about some more serious voltages and currents.



Alan B said:
My back hurts thinking about riding 100 miles on an ebike, unless it is a recumbent.

Higher voltage is not saving any energy at all here. You lose far more in the 4115's greater resistance than you saved on the input wiring losses. The difference in temperature between a 4110 and a 4115 controller is substantial.

This is not about efficiency. It is big, heavy, and powerful. The higher voltage allows driving the motor harder, and at higher speed. That's what the higher voltage is about. Watch those motor and controller temperatures.

Ride safe.
 
Hi Powervelocity, what chargers do you use on your battery? Can you share links? Thank you!
 
Powervelocity.com said:
It was and it still is if you do a bit of math.

33.5Ah times 77v makes 2,579 Wh which makes it half of the capacity of my pack (88v times 58Ah is 5,104Wh). Accounting for euro to dollar conversion rate, 935 euro for 2,579Wh is still more expensive than my pack per amount of energy. ;) I have also recently built a smaller pack with GAs for this frame for a customer build, 15p24s which makes 4,620Wh. I am yet to see anyone building or selling a pack with capacity anywhere closer to mine at a reasonable price or at any price for that matter. So far, it's been mostly 72v 20Ah or 30Ah at best. Heavy and bulky bricks taking all the space in the frame and giving like 20 miles of range.


ABritInNY said:
It was a great deal :), now there is a guy in Europe selling an EEB pack, using the new Sanyo cell, it's a 77v 33.5ah 21s10p pack delivered free!! for like 935 euros, of course that is in Europe, but I guess there is a revolution going on amongst pack builders lately. Viva la revolution :D

I would guess these sizes of packs exist here and there. Not usually for sale, but built for different transportation purposes.
My cargobike uses a 18s26p pack. But since the cells are LG D1s, the capacity is 4kWh somethingsomething.
Your pack is 480 cells compared to 468 in mine.
 
Correct. Larger packs (like above 3kwh) tend to be custom built.

Wheazel said:
Powervelocity.com said:
It was and it still is if you do a bit of math.

33.5Ah times 77v makes 2,579 Wh which makes it half of the capacity of my pack (88v times 58Ah is 5,104Wh). Accounting for euro to dollar conversion rate, 935 euro for 2,579Wh is still more expensive than my pack per amount of energy. ;) I have also recently built a smaller pack with GAs for this frame for a customer build, 15p24s which makes 4,620Wh. I am yet to see anyone building or selling a pack with capacity anywhere closer to mine at a reasonable price or at any price for that matter. So far, it's been mostly 72v 20Ah or 30Ah at best. Heavy and bulky bricks taking all the space in the frame and giving like 20 miles of range.


ABritInNY said:
It was a great deal :), now there is a guy in Europe selling an EEB pack, using the new Sanyo cell, it's a 77v 33.5ah 21s10p pack delivered free!! for like 935 euros, of course that is in Europe, but I guess there is a revolution going on amongst pack builders lately. Viva la revolution :D

I would guess these sizes of packs exist here and there. Not usually for sale, but built for different transportation purposes.
My cargobike uses a 18s26p pack. But since the cells are LG D1s, the capacity is 4kWh somethingsomething.
Your pack is 480 cells compared to 468 in mine.
 
Just an update that the monster battery pack is sold to a happy customer that is building a bike on the same frame.
I am planning to build a few higher voltage (26s, 109.2V) but smaller size battery packs (35Ah, 3.7kWh) rated at 100A (11kw) discharge and fitting this frame.
Estimated range would be 70 miles per charge.

So, if there is any interest, feel free to pm.
 
Darn, i'm late to the game here..

Anyway i wanted to give you a salute for this build. Jamming all that capacity into that frame is amazing. I want to build something like that myself this year and see this build as a role model for that.
 
Thanks. I actually left some space for the charger in that build, so if I were to use ALL the space for the cells and use the latest capacities available, we can be looking at 150 miles of range. I am taking a step back though at the moment and working on a solution that would prioritize complete integration and fast charging over jumbo battery size. In most cases, 50 miles of REAL range at good speeds (40 mph average) is sufficient and easily achievable today in smaller packages, so that leaves a lot of room to play with.
 
Here is what it looks like so far. Some highlights/features:

- Newly designed 3.36kw battery pack: top voltage raised to 109v (26s). Potentially higher top speeds (above 60 mph);
- Estimated range at 40 mph flat: 70 miles;
- 10kw of rated continuous output, 15kw peak;
- Controller is beefier inside out: 24Fets, low RDS, two row design, thicker shell, lots of capacitance for hard acceleration;
- Onboard fast charger (estimated empty to full in 1.5 hour at 120v or 1 hour at 240v);
- All components are inside (the old controller on the downtube is going away);
- BMS and Controller are programmable wirelessly from a phone;
- Four temperature probes inside the frame box (can be used to monitor controller, BMS, battery).

Still need to finish some wiring and do the field tests.

all_inside.jpg
 
Sweet.

What are the two smaller boxes inside the frame? One is a charger, what's the other one?
 
This is a mock up, just trying to see how everything fits. Still having the old controller under the frame mounted, but it's going away with the new bigger controller being mounted inside. This is meant to be completely clean build, everything goes inside.

Inside the frame are 24F controller on the left and 2x Electek S flatpacks siting on top of the battery. Getting 20 amps of 107v DC charge from a standard 120V AC outlet. This pretty big battery gets charged in no time.


fechter said:
Sweet.

What are the two smaller boxes inside the frame? One is a charger, what's the other one?
 
Hopefully you can fit the controller flat against a panel so it gets some heat dissipation. If the side panels are aluminum then almost anywhere would be good but obviously in front is better.
 
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