How do you think solid state batteries will change how we use hardware?

[BalorNG]

Assuming a decent efficient system (80%),

That's a faulty assumption. When you stack controller and motor losses to get the vehicle up the hill, aero and rolling losses while in motion, motor and controller losses when regenerating downhill, and battery charging losses when storing the recovered energy, your assumptions are wildly optimistic.

I think other folks' demonstrated and measured results of up to 10% energy recovery are more in line with what you can expect. Your estimate that you could ever recover two-thirds of battery energy is laughable.

You misread my post.

Again, assume, say, you are PEDALLING to maintain 30kmh on the flat (not that hard if you are a decent rider on a decent bike).
You encounter a hilll. You continue pedalling same cadence, same power, keep speed the same but add progressively more assist.
You crest this hill. You *continue* pedalling with same power, same speed, but now add regen to keep speed this way.

This way rolling resistance and aero losses are constant and irrelevant... it might be hard to do on a really steep hill, right - both when it comes to motor power and battery absorption capacity, but it is possible. It is also possible to have the system considerably more efficient using higher-grade componentry (like astro motors, right, or similar grade inrunners with one step of reduction to keep things at maximum efficiency) and a large battery that can absorb this power (I have 2.3kwh for instance, like 2 or so real but that is good enough for me).

Of course, few actually ride that way, but *I* just might.

 

[ebike4healthandfitness]

It is also possible to have the system considerably more efficient using higher-grade componentry (like astro motors, right, or similar grade inrunners with one step of reduction to keep things at maximum efficiency)

If the goal is maximum regeneration that means climbing the steepest hill possible with the heaviest weight possible until the motor efficiency drops off.

But could it be using two stage reduction is better at doing that because it allows a lower turn motor to be used? For example, would it be better to use an Astro Flight 12T motor with single stage reduction or is better to go 3T and add a 4:1 planetary gearbox? (Both would have the same wheel revolutions per volt)

edit: I suppose another approach would be to still use 12T (and the single stage reduction )but make it a bigger motor and reduce amps.

 

[Chalo]

You encounter a hilll. You continue pedalling same cadence, same power, keep speed the same but add progressively more assist.
You crest this hill. You *continue* pedalling with same power, same speed, but now add regen to keep speed this way.

Using braking so you can continue pedaling effort while riding down hills is absurd. But if that's what turns your crank, I suppose it might as well be regenerative braking.

I think almost everybody can agree that if this is what you want, you're doing it wrong.

 

[BalorNG]

You encounter a hilll. You continue pedalling same cadence, same power, keep speed the same but add progressively more assist.
You crest this hill. You *continue* pedalling with same power, same speed, but now add regen to keep speed this way.

Using braking so you can continue pedaling effort while riding down hills is absurd. But if that's what turns your crank, I suppose it might as well be regenerative braking.

I think almost everybody can agree that if this is what you want, you're doing it wrong.

My goal is to maximise my *aerobic* pedalling effort over very long (hundreds of kilometers) rides while keeping my speed more or less constant. I'm not building a e-bike for rides to the local grocery shop, I can walk there, thank you very much.

My personal goal is 1200 km rides. So far I've only done 200-600 ones.
Hopefully, using e-assist over those rides I can lose enough weight and gain enough aerobic fitness to eventually return doing this entirely human-powered. I don't mind pedalling for hours, it is collapsing on hills I hate.

What I want might something 'a minority of a minority' would want, but no, I'm not doing it wrong, *given my goals*.

 

[BalorNG]

It is also possible to have the system considerably more efficient using higher-grade componentry (like astro motors, right, or similar grade inrunners with one step of reduction to keep things at maximum efficiency)

If the goal is maximum regeneration that means climbing the steepest hill possible with the heaviest weight possible until the motor efficiency drops off.

But could it be using two stage reduction is better at doing that because it allows a lower turn motor to be used? For example, would it be better to use an Astro Flight 12T motor with single stage reduction or is better to go 3T and add a 4:1 planetary gearbox? (Both would have the same wheel revolutions per volt)

This is quite complex actually... by building up your efficiency for edge cases you sacrifice your overall efficiency, unless you can 'turn off' the motor from transmission so it does not contribute it's iron losses.
Do play around with motor simulator...

Using a couple small motors with overrunning clutches in parallel and having electronic control over current so load gets distributed among them the most efficient way possible for DRIVING. (That or gears, but than you'll be forced to vary your speed, instead of using more POWER to ride uphill at SAME speed).
For regen, however, things are not that simple because you cannot have an overruning clutch on one. You'll need a *manual* clutch.
That is possible with (again, small) a friction drive engaged to the tire with a brake handle, this way it can both drive and brake.

On my system I intend to have one belt drive that is capable of regen and is used to maintain efficient cruising speed (actually higher than I can maintain given my fitness and size of my bike, about 35kmh) both up and down hills to a certain point, with constant pedalling effort (both regen and driving peak at about 1kwh electrical, but than it is not maintainable due to overheating and efficiency start to suffer).
Up steep hills crank drive will be engaged providing extra peak 1kwh of power, it has an overruing clutch and singlespeed chain run to it wastes like a 1w running no load.

For truly steep hills, both up and (mostly) down, a friction drive will be used to keep things at peak efficiency all the time, working in tandem with other motors. Due to friction drive limitations it cannot be relied (slippage in wet) upon in all conditions, but having it as an optional extra will help a great deal...

All the while, like I said, 2.3kwh battery will provide enough margin for efficient braking AND acceleration current absorption without using a complex system involving supercaps, lithium titanate or (now unobtanium) solid batteries.

One latter will be avalable, I'll be happy to get them though

 

[Ianhill]

Basic maths means your 2.3kw battery can assist your 1200km trip with on average 1.91wh per kilometer or 750mile journey needs 3wh per mile average.

Ive got down to 10wh on a cargo bike you need a 3rd of that so your gonna have to join the lycra brigade and use the battery just for climb efforts like i did on the cargo even then you need to be cutting through air like a knife.

A simular ride in uk has been done under 40 hours but we are talking prime athelete with gifted dna trained to levels of perfection.

Even then the battery would be a climbing aid to keep the speed up a little so the battery is not used at high speed with big aero losses.

To compare 3wh per mile traveled at 15 miles per hour takes 4 mins thats equivelent power draw to a .75w led been run for 4 mins then add your 20% regen recovery assuming you can regen on the terrain we get around 1wh per minute to average out at over the total 1200km.

I don't know what speed you want to travel at but to break above 15mph aero starts to eat into the losses and thats a high speed to average and the ride would still take 20 hours to complete with only 1wh per mile to assist you.

 

[ebike4healthandfitness]

This is quite complex actually... by building up your efficiency for edge cases you sacrifice your overall efficiency, unless you can 'turn off' the motor from transmission so it does not contribute it's iron losses.
Do play around with motor simulator...

When I compared MAC 6T with added 2:1 reduction to MAC 12T I did see a drop in the peak efficiency (due to the added reduction) but the efficiency in the low end through upper mid range improved. If I were mostly in hilly terrain I think I would do better with the added reduction and lower motor resistance of the 6T.

 

[BalorNG]

Basic maths means your 2.3kw battery can assist your 1200km trip with on average 1.91wh per kilometer or 750mile journey needs 3wh per mile average.

Ive got down to 10wh on a cargo bike you need a 3rd of that so your gonna have to join the lycra brigade and use the battery just for climb efforts like i did on the cargo even then you need to be cutting through air like a knife.

A simular ride in uk has been done under 40 hours but we are talking prime athelete with gifted dna trained to levels of perfection.

Even then the battery would be a climbing aid to keep the speed up a little so the battery is not used at high speed with big aero losses.

To compare 3wh per mile traveled at 15 miles per hour takes 4 mins thats equivelent power draw to a .75w led been run for 4 mins then add your 20% regen recovery assuming you can regen on the terrain we get around 1wh per minute to average out at over the total 1200km.

I don't know what speed you want to travel at but to break above 15mph aero starts to eat into the losses and thats a high speed to average and the ride would still take 20 hours to complete with only 1wh per mile to assist you.

Well, so far I'll be happy with 500-600 and 'mere' 18-19 mph. And I *am* sort of lycra brigade to begin with...
When I was in a better form for I could average 16mph over 400km with considerable elevation gain:

https://www.strava.com/activities/147943553
(On MTB, btw).

Unfortunately, I cannot repeat this feat w/o considerable assist now.

As for 1200+, that's where streamlined fairing and/or solar roof will come into play, I know even 2kwh will not be anywhere near enough and once its dead it is dead weight.

 

[Ianhill]

Axial flux motor improve torque production while keeping no load current small as possible, i see the inertia of these motors is low but torque high so if one could be mounted as a hub motor the improvement in torque to weight would be drastic.

Regen ability would be huge the field lines are all inline when it comes to a radial motor most the field lines are external to the area work is been done, only issue i can see is drag unless its coreless and that will reduce torque and increase rpm dont want that on a hub so maybe the only problem to market is unpowered drag.

What ever you choose it needs low inertia high torque little cogging resistance to yourself while been able to regen hard.

If someone cracks the drag aspect of axial and hubs then theres a giant leap forward in design and power usage for the hub gang avaliable

 

[ebike4healthandfitness]

Axial flux motor improve torque production while keeping no load current small as possible, i see the inertia of these motors is low but torque high so if one could be mounted as a hub motor the improvement in torque to weight would be drastic.

Regen ability would be huge the field lines are all inline when it comes to a radial motor most the field lines are external to the area work is been done, only issue i can see is drag unless its coreless and that will reduce torque and increase rpm dont want that on a hub so maybe the only problem to market is unpowered drag.

What ever you choose it needs low inertia high torque little cogging resistance to yourself while been able to regen hard.

If someone cracks the drag aspect of axial and hubs then theres a giant leap forward in design and power usage for the hub gang avaliable

If the major problem is unpowered drag then how about using as a friction drive with a powered swing arm? This to allow the motor's roller to engage the tire on the fly.

The Alizeti 300C is a friction drive with a powered swing arm.

 

[BalorNG]

Axial flux motor improve torque production while keeping no load current small as possible, i see the inertia of these motors is low but torque high so if one could be mounted as a hub motor the improvement in torque to weight would be drastic.

Regen ability would be huge the field lines are all inline when it comes to a radial motor most the field lines are external to the area work is been done, only issue i can see is drag unless its coreless and that will reduce torque and increase rpm dont want that on a hub so maybe the only problem to market is unpowered drag.

What ever you choose it needs low inertia high torque little cogging resistance to yourself while been able to regen hard.

If someone cracks the drag aspect of axial and hubs then theres a giant leap forward in design and power usage for the hub gang avaliable

If the major problem is unpowered drag then how about using as a friction drive with a powered swing arm? This to allow the motor's roller to engage the tire on the fly.

The Alizeti 300C is a friction drive with a powered swing arm.

So long as you are using either assist or regen ALL of the time, this is not much an issue... But even than if you are riding at high speed and using very low level of assist or regen, your efficiency will suffer because iron losses will be considerably higher than copper losses and will be a significant part of power output (let's say you are using 60w of assist with no load drag of 30w - copper losses will be close to zero, BUT your efficiency is still 50%).

Even using very, very thin laminations is not a panacea because they do not reduce HYSTERESIS torque loss component as much as I understand.

So yea, only way to have ultimate effiency is to have a motor that can be engaged and disengaged from transmission or one that has no no-load losses like induction motor or switched reluctance motor...

 

[Ianhill]

Question is how to dis/engage electronically without using more energy than existing systems.

A puck clutch is direct light and efficent but needs effort to engage and disengage the system needs to sense throttle/regen input and instantly act not an easy task.

Mobility scooters use electric brakes maybe this system could be reversed and improved upon as the engagement method but the motor would need an esp32 or simular monitoring the throttle amd regen and bringing the clutch in and out accordingly adding alot more complex but the move to axial on top of cogging removal would be the selling ticket for even bafang and alike to copy i think.

Lets face it few more electeical component's and the occasional clutch pack change wouldnt be the end of the world if the motor run a good few thousand miles while improving all aspects of the experience.

 

[ebike4healthandfitness]

Axial flux motor improve torque production while keeping no load current small as possible, i see the inertia of these motors is low but torque high so if one could be mounted as a hub motor the improvement in torque to weight would be drastic.

Regen ability would be huge the field lines are all inline when it comes to a radial motor most the field lines are external to the area work is been done, only issue i can see is drag unless its coreless and that will reduce torque and increase rpm dont want that on a hub so maybe the only problem to market is unpowered drag.

What ever you choose it needs low inertia high torque little cogging resistance to yourself while been able to regen hard.

If someone cracks the drag aspect of axial and hubs then theres a giant leap forward in design and power usage for the hub gang avaliable

If the major problem is unpowered drag then how about using as a friction drive with a powered swing arm? This to allow the motor's roller to engage the tire on the fly.

The Alizeti 300C is a friction drive with a powered swing arm.

So long as you are using either assist or regen ALL of the time, this is not much an issue... But even than if you are riding at high speed and using very low level of assist or regen, your efficiency will suffer because iron losses will be considerably higher than copper losses and will be a significant part of power output (let's say you are using 60w of assist with no load drag of 30w - copper losses will be close to zero, BUT your efficiency is still 50%).

Even using very, very thin laminations is not a panacea because they do not reduce HYSTERESIS torque loss component as much as I understand.

So yea, only way to have ultimate effiency is to have a motor that can be engaged and disengaged from transmission or one that has no no-load losses like induction motor or switched reluctance motor...

Yeah for something like that it does make sense not only to have a "neutral" (i.e. roller not contact with tire) but maybe even to lock out lower levels of pedal assist once the bike reaches certain speeds. For example, let's say a person starts off with level 1 assist....once at a certain speed the roller disengages from the tire. For level 2 assist the point at which the roller disengages from the tire would be a higher mph. This so someone doesn't inadvertently waste too much energy with axial flux motored friction drive ebike.

 

[spinningmagnets]

My first Ebike is was a DIY friction-drive. The "drag" when unpowered is theoretical. For me, it was never a problem. The tire-roller was held onto a shaft by two one-way clutch-bearings...

 

[Chalo]

My first Ebike is was a DIY friction-drive. The "drag" when unpowered is theoretical. For me, it was never a problem. The tire-roller was held onto a shaft by two one-way clutch-bearings...

Did you use EV Warrior parts for that bike?

 

[JackFlorey]

One change I can imagine is locked clutch geared hubs replacing traditional clutched geared hubs. . . .Another thing I can imagine is rental mopeds becoming more common. These capable of transporting two people and equipped with more powerful motors and higher capacity batteries than an ebike.

All these things are possible now with existing batteries. Indeed, they exist. (Google GMAC and Lyft bikeshare)

 

[spinningmagnets]

Did you use EV Warrior parts for that bike?

It was made from scratch, but it was very similar in its operation...from 2010 (*am I really that old?)

https://endless-sphere.com/forums/viewtopic.php?f=28&t=21365&start=75#p336206

 

[ebike4healthandfitness]

One change I can imagine is locked clutch geared hubs replacing traditional clutched geared hubs. . . .Another thing I can imagine is rental mopeds becoming more common. These capable of transporting two people and equipped with more powerful motors and higher capacity batteries than an ebike.

All these things are possible now with existing batteries. Indeed, they exist. (Google GMAC and Lyft bikeshare)

I knew about GMAC.

The Lyft BikeShare bike is just a little 500 watt ebike. It would not be able to take two passengers up a hill at a decent speed. To do that you would need much more than a 500 watt hub motor.

 

[MadRhino]

One change I can imagine is locked clutch geared hubs replacing traditional clutched geared hubs. . . .Another thing I can imagine is rental mopeds becoming more common. These capable of transporting two people and equipped with more powerful motors and higher capacity batteries than an ebike.

All these things are possible now with existing batteries. Indeed, they exist. (Google GMAC and Lyft bikeshare)

The typical rental e-scooters here can carry 2 adults. Some have 72v 20 A/h batteries, and room for double capacity. Better performance than 50cc gassers in acceleration and top speed. Of course they wouldn’t survive very long with a geared motor, locked clutch or not, for they are about 160 lbs without the double capacity upgrade. The future of geared motors need to be bigger and cooled, otherwise they will always be limited to lightweight and low performance ebikes. Lighter batteries are a dream for e-riders, but they won’t change much the way we build. They will let us build longer range commuters, or lighter pedelecs.

 

[Chalo]

The Lyft BikeShare bike is just a little 500 watt ebike. It would not be able to take two passengers up a hill at a decent speed. To do that you would need much more than a 500 watt hub motor.

Do you have any relevant experience with it, or are you thinking out loud again, poorly?

Go get some actual e-bike experience with a range of different machines. Then maybe you can start telling us all how it is with those specific machines.

 

[ebike4healthandfitness]

The Lyft BikeShare bike is just a little 500 watt ebike. It would not be able to take two passengers up a hill at a decent speed. To do that you would need much more than a 500 watt hub motor.

Do you have any relevant experience with it, or are you thinking out loud again, poorly?

Go get some actual e-bike experience with a range of different machines. Then maybe you can start telling us all how it is with those specific machines.

Having a bad day?

Somebody got under your skin today and perhaps you feel the need to aggravate someone else to feel better?

Chalo, the bike only has seating for one person for crying out loud!!!

Yeah, it's not meant for carrying two adults up a hill at decent speed.....and I don't know any street legal 500 watt hub motor that can.

 

[markz]

Chalo is on a roll tonight :thumb:

Don't take it personally -ebike4healthguy- after all its the internet, we are all strangers passing by in the middle of the night no matter if the suns still out or not.
500w mid drive can pull a lot of weight
a 500w hub motor laced in a small wheel with the right hub kv matched to proper voltage and current can pull a lot of weight
There are many ways to get up a hill with weight.

Yeah, it's not meant for carrying two adults up a hill at decent speed.....and I don't know any street legal 500 watt hub motor that can.

 

[ebike4healthandfitness]

a 500w hub motor laced in a small wheel with the right hub kv matched to proper voltage and current can pull a lot of weight
There are many ways to get up a hill with weight.

It's not laced to a small wheel though.

And remember these are OEM street legal builds, not hot rodded with higher voltage and current.

Yeah no way is something like that going up a hill at decent speed with two adults...and hence it is provisioned with a seat for one person, not two.

 

[markz]

The Lyft BikeShare bike is just a little 500 watt ebike. It would not be able to take two passengers up a hill at a decent speed.To do that you would need much more than a 500 watt hub motor.

I have no clue what those rental ebikes are, best guess is 36V 15-18A and 10Ah maybe 15Ah.
I can't envision the Lime ebikes, google helps, yea so the batteries a good size. Easy access to the battery on top of the rear rack with one big tube to the seat, and 2 thin tubes at the back of the rack.
Here, Lime ebikes went away 2 yrs ago. I never had a chance to see how weak they were.

The stand up e-scooters batteries are more encased, with audio alarm when moved is routed to the handlebars which the noise could probably be dampened with duct tape, gps my guess is in the bms on battery. I tried to rent one once, but I couldnt find it and they still charged me $5 because it was rush hour. 36V would be my guess, 10Ah at most is another guess.

I wonder if anyone has opened one up a rental ebike or escooter yet.

a 500w hub motor laced in a small wheel with the right hub kv matched to proper voltage and current can pull a lot of weight
There are many ways to get up a hill with weight.

It's not laced to a small wheel though.

And remember these are OEM street legal builds, not hot rodded with higher voltage and current.

Yeah no way is something like that going up a hill at decent speed with two adults...and hence it is provisioned with a seat for one person, not two.

 

[MadRhino]

Here the corporate rental ebikes and scooters lasted only one season. Ebike rental is now a city monopole, and scooters are from local shops who are taking over the gassers market. Some are pretty good. I did ride one of them this sumner, took a 180 lbs friend as passenger and climbed 10% at near 40 mph top speed. I find them slow cows as compared to my bikes, but they have their advantages: lots of luggage room, passenger seat, full rain proofing, integrated thief safety, relatively fast charging (10A), very robust tubeless tires... stiff and silent on rough/under construction street sections after minimal mods.

I was quite happy with it, even did some moderate off road. The local police doesn’t apply ebike laws. They apply the street code laws. It does help a lot the emergence of alternate transportation in the city. And, the actual administration had made many changes to reduce car trafic in the residential areas, mostly bottlenecks at every corner, many one-way streets, lots of speed bumps, less parking space...