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

[ebike4healthandfitness]

One change I can imagine is locked clutch geared hubs replacing traditional clutched geared hubs. With a 2.5x energy density increase and a max charging increase from 1C to 4C or 6C even a small hidden in the downtube battery will be able fully absorb Regen energy from many downhill descents.

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. This supported by urban charging stations capable of charging beyond 120v 15amp or 20amp.

 

[Chalo]

I don't think it's worth your time to think about it until they are 1) available, 2) reliable, and 3) cheap enough to make sense economically. Until there's an actual product with a published spec that's independently verified to be accurate, you don't even know what you'll be working with.

I know I've been reading gee-whiz new battery performance claims since the 1980s. Once some of it (like lithium ion) finally came out, it was quite a while before it was affordable enough to displace boring old tech on a cost/benefit basis.

 

[MadRhino]

Solid state batteries are a dream for now. Japan is supposed to start a small production soon, but they will be very small. It is an experiment, because so far nobody had not solved all the problems.

Then, what batteries have to do with geared hubs? They are sh*t for any performance, and batteries are not responsible for their limitations.

Some E-mopeds already can carry two persons, accelerate cars from a standstill, and regen is common. I have one here, cheaper than the e-mtb that I build, yet can ride 40 miles at 40 mph on motor alone, and it has room for 3 times the batteries if required for better performance or range.

Solid state batteries are the future, for safety only. Anything else they will be capable of, had been done already.

 

[ebike4healthandfitness]

Then, what batteries have to do with geared hubs? They are sh*t for any performance, and batteries are not responsible for their limitations.

Remember how even this not so steep hill (and a lightweight rider) sent 500 to 800 watts of regen energy to the battery.

https://youtu.be/cnaucA7qVGs?t=229

Most OEM bikes with geared hubs don't have a battery large enough to absorb even that....let alone the regen that would be created by a heavier rider on a steeper hill (via a locked clutch geared hub like the GMAC):

On geared hub bikes with hidden batteries like the FLX Babymaker the situation is even worse as the Babymaker only has a 252 Watt hour battery (36v 7ah).

https://flx.bike/collections/all-ebikes/products/babymaker

Even at 1C with a light rider on a not so steep hill it's battery would collect less than 1/3 to half the regen energy available. (A lot of potential is not able to be used with this bike (assuming they changed the geared hub to GMAC locked geared hub) because the battery is holding it back in more ways than one. Still a nice bike though.)

 

[BalorNG]

Regen makes sense for a clyde on a recumbent. Nearly mandatory for someone on a streamlined e-vehicle riding in hilly terrain.
Otherwise you'll hardly 'outregen' even no-load coasting losses... ask yourself - how often do you change brake pads? if answer is 'hardly ever' - regen makes sense only if your motor is already direct drive so this is a bonus, but they are usually extremely heavy.

 

[ebike4healthandfitness]

Regen makes sense for a clyde on a recumbent. Nearly mandatory for someone on a streamlined e-vehicle riding in hilly terrain.

I've heard the aerodynamics argument before....but fact remains that even a lightweight rider in the upright riding position (i.e. poor aerodynamics to energy ratio) can still regen enough to overwhelm the average battery going down a not so steep hill.

The heavier the rider, the steeper the hill, the more efficient the hub at lower speeds = the greater the amount of watts sent to the battery. If the amount of energy sent to the battery exceeds the battery charge rate then any amount above the battery's charge rate threshold just becomes wasted, non-regenerated energy.

 

[BalorNG]

Regen makes sense for a clyde on a recumbent. Nearly mandatory for someone on a streamlined e-vehicle riding in hilly terrain.

I've heard the aerodynamics argument before....but fact remains that even a lightweight rider in the upright riding position (i.e. poor aerodynamics to energy ratio) can still regen enough to overwhelm the average battery going down a not so steep hill.

The heavier the rider, the steeper the hill, the more efficient the hub at lower speeds = the greater the amount of watts sent to the battery. If the amount of energy sent to the battery exceeds the battery charge rate then any amount above the battery's charge rate threshold just becomes wasted, non-regenerated energy.

Yea, steep hills are way different. That's where it helps a LOT.
But regarding batteries - it does not work that way. Batteries will happily accept more than 1C of charge *short term*, BUT will heat up and degrade a tiny bit... there is a limit of course, but it is not a HARD limit.
Since going up hill usually require considerably more energy than modulating speed downhill (unless panic braking), due to rolling resistance and aero working against you, it takes really *crawling* up a steep hill on a combination of human power and DD motor and than 'riding brakes' downhill to truly overwhelm a battery I think, otherwise your battery will be overwhelmed both UP and down...

 

[BalorNG]

Regen makes sense for a clyde on a recumbent. Nearly mandatory for someone on a streamlined e-vehicle riding in hilly terrain.

I've heard the aerodynamics argument before....but fact remains that even a lightweight rider in the upright riding position (i.e. poor aerodynamics to energy ratio) can still regen enough to overwhelm the average battery going down a not so steep hill.

The heavier the rider, the steeper the hill, the more efficient the hub at lower speeds = the greater the amount of watts sent to the battery. If the amount of energy sent to the battery exceeds the battery charge rate then any amount above the battery's charge rate threshold just becomes wasted, non-regenerated energy.

Also, you can not just 'ride the brakes', but ride the brakes *slowly* downhill to both maximise energy recuperation AND do not overwhelm your battery.

Again, play with sliders on that site:

https://www.gribble.org/cycling/power_v_speed.html

It has readily available calculated 'braking power' for you to see.

 

[ebike4healthandfitness]

Regen makes sense for a clyde on a recumbent. Nearly mandatory for someone on a streamlined e-vehicle riding in hilly terrain.

I've heard the aerodynamics argument before....but fact remains that even a lightweight rider in the upright riding position (i.e. poor aerodynamics to energy ratio) can still regen enough to overwhelm the average battery going down a not so steep hill.

The heavier the rider, the steeper the hill, the more efficient the hub at lower speeds = the greater the amount of watts sent to the battery. If the amount of energy sent to the battery exceeds the battery charge rate then any amount above the battery's charge rate threshold just becomes wasted, non-regenerated energy.

Also, you can not just 'ride the brakes', but ride the brakes *slowly* downhill to both maximise energy recuperation AND do not overwhelm your battery.

Again, play with sliders on that site:

https://www.gribble.org/cycling/power_v_speed.html

It has readily available calculated 'braking power' for you to see.

That is a good tool.........but.......it only tells the user how many watts it takes to hold the bike to a certain speed down a hill.

It doesn't tell many watts it takes to actually stop the bike on a downhill (e.g. stop sign on bottom of hill). Peak watts for this will be much higher depending on how quick the stop needs to be.

 

[LewTwo]

It doesn't tell many watts it takes to actually stop the bike on a downhill (e.g. stop sign on bottom of hill).

In my experience,
a rather large pothole can provide "quickest" stop for an E-Bike ....
not necessarily the rider

 

[BalorNG]

Regen makes sense for a clyde on a recumbent. Nearly mandatory for someone on a streamlined e-vehicle riding in hilly terrain.

I've heard the aerodynamics argument before....but fact remains that even a lightweight rider in the upright riding position (i.e. poor aerodynamics to energy ratio) can still regen enough to overwhelm the average battery going down a not so steep hill.

The heavier the rider, the steeper the hill, the more efficient the hub at lower speeds = the greater the amount of watts sent to the battery. If the amount of energy sent to the battery exceeds the battery charge rate then any amount above the battery's charge rate threshold just becomes wasted, non-regenerated energy.

Also, you can not just 'ride the brakes', but ride the brakes *slowly* downhill to both maximise energy recuperation AND do not overwhelm your battery.

Again, play with sliders on that site:

https://www.gribble.org/cycling/power_v_speed.html

It has readily available calculated 'braking power' for you to see.

That is a good tool.........but.......it only tells the user how many watts it takes to hold the bike to a certain speed down a hill.

It doesn't tell many watts it takes to actually stop the bike on a downhill (e.g. stop sign on bottom of hill). Peak watts for this will be much higher depending on how quick the stop needs to be.

You can use mechanical brakes for that. If you slow down by using regen first, energy un-harvested by regen will be minimal... KE is a function of weight and speed SQUARED.

 

[Ianhill]

Theres lto cells thats small enough to fit a bike and take upto 30000 cycles but the capacity is low compared to an 18650 at 20c but if you ride cold weathers then there will come a temp point where the lto becomes the clear leader id guess around 6c and lower plus at that temp the 18650 may have 200 cycles.

I had a 350wh 10s pack in a bike just over 12ah and that was enough for me to do 35miles and older person maybe 20 or so but you start climbing and decending there's enough boost to help assist one or 2 small hills maybe at the end of the ride i doubt its a game changer oyher than the fact it could be easy it implent an abs system if the regen brake can be made strong enough.

I still wouldnt ditch my disc brake system but i would reduce my rotors from 203mm down to 160 and a single piston cable rather tham hydraulic just to keep them as emergency stop it would be a complex fix for a problem that barely existed abs is pointless when its easy to fell modulation through the lever of whats going on and the lto regen aspect is to clunky to be worthy unless your climbing the alps etc.

 

[ebike4healthandfitness]

I've heard the aerodynamics argument before....but fact remains that even a lightweight rider in the upright riding position (i.e. poor aerodynamics to energy ratio) can still regen enough to overwhelm the average battery going down a not so steep hill.

The heavier the rider, the steeper the hill, the more efficient the hub at lower speeds = the greater the amount of watts sent to the battery. If the amount of energy sent to the battery exceeds the battery charge rate then any amount above the battery's charge rate threshold just becomes wasted, non-regenerated energy.

Also, you can not just 'ride the brakes', but ride the brakes *slowly* downhill to both maximise energy recuperation AND do not overwhelm your battery.

Again, play with sliders on that site:

https://www.gribble.org/cycling/power_v_speed.html

It has readily available calculated 'braking power' for you to see.

That is a good tool.........but.......it only tells the user how many watts it takes to hold the bike to a certain speed down a hill.

It doesn't tell many watts it takes to actually stop the bike on a downhill (e.g. stop sign on bottom of hill). Peak watts for this will be much higher depending on how quick the stop needs to be.

You can use mechanical brakes for that. If you slow down by using regen first, energy un-harvested by regen will be minimal... KE is a function of weight and speed SQUARED.

A 165 lb rider on a 50 lb bike going down a 8 percent grade needs 499 watts braking force just to hold speed at 20 mph. That is quite a bit of braking force needed considering the weight of rider/bike and grade of slope. It's quite easy to imagine situations that would commonly exceed that. Braking to actually slow down from 20 mph would be greater than 499 watts depending on the rate of deceleration desired.

Therefore I can see why OEM ebikes with geared hubs don't have locked clutches when the most common battery size for them is 350 Wh to 500 Wh.

It is just so easy to see in many situations for many riders a good amount of energy won't be regenerated because the battery charge rate is the bottleneck.

As far as the mechanical brakes go a person shouldn't have to use those except under extreme circumstances. The Regen system should be able to stop the bike in a reasonable distance without wasting energy. This so a person can ride their bike as the they normally would without compromising Regen.

 

[BalorNG]

Also, you can not just 'ride the brakes', but ride the brakes *slowly* downhill to both maximise energy recuperation AND do not overwhelm your battery.

Again, play with sliders on that site:

https://www.gribble.org/cycling/power_v_speed.html

It has readily available calculated 'braking power' for you to see.

That is a good tool.........but.......it only tells the user how many watts it takes to hold the bike to a certain speed down a hill.

It doesn't tell many watts it takes to actually stop the bike on a downhill (e.g. stop sign on bottom of hill). Peak watts for this will be much higher depending on how quick the stop needs to be.

You can use mechanical brakes for that. If you slow down by using regen first, energy un-harvested by regen will be minimal... KE is a function of weight and speed SQUARED.

A 165 lb rider on a 50 lb bike going down a 8 percent grade needs 499 watts braking force to hold speed at 20 mph. That is quite a bit of braking force needed considering the weight of rider/bike and grade of slope. It's quite easy to imagine situations that would commonly exceed that.

Therefore I can see why OEM ebikes with geared hubs don't have locked clutches when the most common battery size for them is 350 Wh to 500 Wh.

It is just so easy to see in many situations for many riders a good amount of energy won't be regenerated because the battery charge rate is the bottleneck.

As far as the mechanical brakes go a person shouldn't have to use those except under extreme circumstances. The Regen system should be able to stop the bike in a reasonable distance without wasting energy. This so a person can ride their bike as the they normally would without compromising Regen.

The fact that in RARE circumstances safe regen might overwhelm battery is the reason for limit on regen battery current in the controller, not to dump the concept altogether. Are are suffering from a particularly bad case of purism - this stuff is nasty, you know . A combination of regen and mechanical braking works wonderfully by simply using a typical e-bike brake handle, you do not even need a variable regen one. Press lightly - the mechanical brakes don't touch the disk yet, but the motor engages and does the regen, scrubbing speed in efficient manner. For panic/complete stop - just press it hard!

Btw, when you brake with, say, 500w of battery current, actual braking power might actually be close to double that depending on phase current - when it comes to regen braking, even LOSSES provide useful braking force!

 

[Chalo]

when it comes to regen braking, even LOSSES provide useful braking force!

And motor heating during a time when the motor would otherwise be cooling down.

 

[donn]

As far as the mechanical brakes go a person shouldn't have to use those except under extreme circumstances. The Regen system should be able to stop the bike in a reasonable distance without wasting energy. This so a person can ride their bike as the they normally would without compromising Regen.

That's about how it works with common fixed regen ca. 200-300W. We use our brakes under extreme circumstances - any time we come to a complete stop, have to slow down quickly on a downhill grade, on 8% downhills, etc. Brakes last a long time.

 

[ebike4healthandfitness]

That is a good tool.........but.......it only tells the user how many watts it takes to hold the bike to a certain speed down a hill.

It doesn't tell many watts it takes to actually stop the bike on a downhill (e.g. stop sign on bottom of hill). Peak watts for this will be much higher depending on how quick the stop needs to be.

You can use mechanical brakes for that. If you slow down by using regen first, energy un-harvested by regen will be minimal... KE is a function of weight and speed SQUARED.

A 165 lb rider on a 50 lb bike going down a 8 percent grade needs 499 watts braking force to hold speed at 20 mph. That is quite a bit of braking force needed considering the weight of rider/bike and grade of slope. It's quite easy to imagine situations that would commonly exceed that.

Therefore I can see why OEM ebikes with geared hubs don't have locked clutches when the most common battery size for them is 350 Wh to 500 Wh.

It is just so easy to see in many situations for many riders a good amount of energy won't be regenerated because the battery charge rate is the bottleneck.

As far as the mechanical brakes go a person shouldn't have to use those except under extreme circumstances. The Regen system should be able to stop the bike in a reasonable distance without wasting energy. This so a person can ride their bike as the they normally would without compromising Regen.

The fact that in RARE circumstances safe regen might overwhelm battery is the reason for limit on regen battery current in the controller, not to dump the concept altogether. Are are suffering from a particularly bad case of purism - this stuff is nasty, you know . A combination of regen and mechanical braking works wonderfully by simply using a typical e-bike brake handle, you do not even need a variable regen one. Press lightly - the mechanical brakes don't touch the disk yet, but the motor engages and does the regen, scrubbing speed in efficient manner. For panic/complete stop - just press it hard!

Btw, when you brake with, say, 500w of battery current, actual braking power might actually be close to double that depending on phase current - when it comes to regen braking, even LOSSES provide useful braking force!

I understand how regen brakes work cooperatively with mechanical brakes. I also understand how a hub can apply more braking watts than it sends to the battery (at the cost of the controller and hub heating up).

But this thread is about geared hubs on oem bikes.

Why are these bikes (typically equipped with 350 Wh to 500 Wh batteries) not currently coming with locked clutches? How would batteries with higher charge rates change that?

 

[Chalo]

Why are these bikes (typically equipped with 350 Wh to 500 Wh batteries) not currently coming with locked clutches?

It's because it sucks to ride a bike like that. If you pedal AT ALL, not being able to coast worth a damn is a bigger handicap and bummer than any amount of regen can offset.

Regenerative braking is a fetish item. You get all juicy for it, but regular bike riders don't care. They care that their bike drags and fights against them.

 

[ebike4healthandfitness]

Why are these bikes (typically equipped with 350 Wh to 500 Wh batteries) not currently coming with locked clutches?

It's because it sucks to ride a bike like that. If you pedal AT ALL, not being able to coast worth a damn is a bigger handicap and bummer than any amount of regen can offset.

Regenerative braking is a fetish item. You get all juicy for it, but regular bike riders don't care. They care that their bike drags and fights against them.

I think regenerative braking is a very practical thing but ebikes are so restricted in terms of charge rate that it only works well in a few corner cases.

Something like the HD Livewire + 200 lb rider has a much better ratio of battery capacity (and thus charge rate) compared to a 50 lb OEM ebike and 200 lb rider.

HD Livewire + 200 lb rider has 749 lb total weight but 15.5 Wh battery ( 13.3 Wh usable).

50 lb OEM geared hub ebike + 200 lb rider has 250 lb total weight, but only 350 to 500 Wh.

 

[Chalo]

Regenerative braking is a fetish item. You get all juicy for it, but regular bike riders don't care. They care that their bike drags and fights against them.

I think regenerative braking is a very practical thing

Yeah, you think that. See above.

 

[ebike4healthandfitness]

Regenerative braking is a fetish item. You get all juicy for it, but regular bike riders don't care. They care that their bike drags and fights against them.

I think regenerative braking is a very practical thing

Yeah, you think that. See above.

The bike drag can be fixed with virtual freewheel though.

And a bike without a restricted charge rate will have plenty of energy for that thru Regen.

 

[Chalo]

By the way, it's "bike4healthandfitness" or "ebike4agingdisabilityandlaziness". Just sayin'. We can all fess up to where we belong in that regard.

 

[BalorNG]

when it comes to regen braking, even LOSSES provide useful braking force!

And motor heating during a time when the motor would otherwise be cooling down.

That is why a proper system should consist of a very light swingarm/chainstay-mounted middrive with belt drive/reduction to the rear hub with an other step of reduction inside the hub the same way it is done in geared motors (basically a high reduction ratio single speed IGH... or even 2-3 speed for that matter).

Light, low noise, efficient, belt can slide on and off easily when removing the wheel, no retentioning need (it works on my system), no wires to the wheel, low maintenance, excellent heat shedding (swingarm/frame acting as heat sink!)

The bike drag can be fixed with virtual freewheel though.

It is still losses, and in takes considerale stop/go cycles or hills your so steep you need to modulate your speed to outregen them.
It is much better to battle those losses with very thin laminations, too. 0.2mm and even 0.15mm are common on RC motors now and they do not cost a fortune!

By the way, it's "bike4healthandfitness" or "ebike4agingdisabilityandlaziness". Just sayin'.

Now you are just being mean.

 

[ebike4healthandfitness]

The bike drag can be fixed with virtual freewheel though.

It is still losses, and in takes considerale stop/go cycles or hills your so steep you need to modulate your speed to outregen them.
It is much better to battle those losses with very thin laminations, too. 0.2mm and even 0.15mm are common on RC motors now and they do not cost a fortune!

With higher charge rate batteries it will take far less hills and stops to outregen the no load losses. On top of that remember the bike will charge faster from an outlet (assuming a high watt charger comes with it) or perhaps even be able to use an adapted ev charger.

 

[ebike4healthandfitness]

That is why a proper system should consist of a very light swingarm/chainstay-mounted middrive with belt drive/reduction to the rear hub with an other step of reduction inside the hub the same way it is done in geared motors (basically a high reduction ratio single speed IGH... or even 2-3 speed for that matter).

Why not use a planetary gearbox directly attached to the RC motor? Wouldn't this have the added benefit of stabilizing the RC motor's output shaft?