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

ZeroEm said:
Some reason unknown to me. Have been focused on a two speed. So have been thinking about dual voltage system (sounds craze to me too.). Currently ride greenways and with regular bikers at 15 mph. Then less often ride the roads outside of town and with roadie bikes which is faster 20 -28 mph.

Have been thinking about having the option of switching from 36v to 72v. This would keep me in the best range for each task. My current controller can't do 36v, the Phaserunner can. My current batteries drops (splits) from 72v to 36v currently with a flip of a switch. (use this only when connecting the battery currently)

Then there is the settings not matching the battery voltage. And would worry about staying in balance. Would not want to switch back and forth during a ride. The only reason for me to think of such is that the greenway riding will get better w/km and keep my motor from running the 35-50% range. At 36v would be max out at 17 mph and 72v would be 33 mph. Don't think I will do this, just need two different bikes. But there it is, comments?

by MadRhino » Oct 10 2021 10:05am

Then we are back to the topic of energy density, which is the solution that will make obsolete such redundancy, complicated design with 25 times the moving parts for the purpose of saving power usage.

Can a person run at 36v but with double the amps of 72v?
 
ebike4healthandfitness said:
Can a person run at 36v but with double the amps of 72v?
Sure. But the motor constant won't change, so without phase advance the top speed of the 36V will be half of the 72V system. (Even with phase advance there's only so much you can do.) You could of course choose a new motor with twice the motor constant.

Also you need twice the copper and twice the silicon to get the same power at the lower voltage.
 
JackFlorey said:
ebike4healthandfitness said:
Can a person run at 36v but with double the amps of 72v?
Sure. But the motor constant won't change, so without phase advance the top speed of the 36V will be half of the 72V system. (Even with phase advance there's only so much you can do.) You could of course choose a new motor with twice the motor constant.

Also you need twice the copper and twice the silicon to get the same power at the lower voltage.

I like the idea of 36v having half the speed of 72v, but with the same power.

So assume with phaserunner hitting 50 amps 36v would make 1440 watts assuming 80 percent efficiency. Likewise at 72v and 25 amps power would also be 1440w (if motor is 80 percent efficient).

36v at 50 amps for climbing and Regen down steep hills.

72v at 25 amps for flat ground or slight grades.

The ultimate (regen) moped set-up if it could be made to switch on the fly?
 
You might as well do two motors, one front and one rear if your doing a moped.
Front = big direct drive
Rear = big geared motor, like a MAC or GMAC.
Then match the KV's to the controller's and speed you want.
Two independent systems, could be used on one battery.

ebike4healthandfitness said:
The ultimate (regen) moped set-up if it could be made to switch on the fly?
 
markz said:
You might as well do two motors, one front and one rear if your doing a moped.
Front = big direct drive
Rear = big geared motor, like a MAC or GMAC.
Then match the KV's to the controller's and speed you want.
Two independent systems, could be used on one battery.

ebike4healthandfitness said:
The ultimate (regen) moped set-up if it could be made to switch on the fly?

One of the GMAC windings (I forgot if it was the 8T or 10T) matches up very very close to one of the Grin All axle motor windings (forgot which one but I vaguely remember it being the fast one, which is the middle speed winding).....so what you are saying is possible. But I think being able to switch 72v 25 amp to 36v 50amp on a single GMAC motor would make a better British Columbia (and non-california US moped) assuming it could made to switch voltage and amps on the fly. My only reservation is the MAC hub (which GMAC is based on) is not rated above 1000w by the manufacturer.

Having two speed ranges both at 1440 watts would overall efficient than one speed range that is twice as broad also at 1440 watts.
 
markz said:
I just like cruise control because I go a constant speed but its hard to engage on bumpy pathways, hold throttle steady for 10 seconds. Then other times cruise is engaged when you dont want it.
CA provides a user selectable CC Set period out of several preset hold times (shortest is 3s, but you're right, the shorter set period is more apt to engage more unwanted CC sets). Isn't there a way to engage CC with a thumb switch or similar?
 
Well I think its quite easy to use two batteries and one controller. As I previously posted about a switch and diodes.
The only downside is my generic controller is 36V 35A with lvc resistor network
When I switch from my 36V battery (no bms) to my 52V 14.5Ah 40A (bms) battery, its still limited to 35A with zero lvc help from the controller. And since the controller has 60V capacitors the max voltage on the 14S 52V is 58.80V which is plenty of room. You could just go with any old generic controller with 100V capacitors and change the lvc resistor network, or just have batteries with a bms to cut off when it hit its limit.
I just manually change my batteries around. Flipping a switch would be easy, see a hill and low on the 36V battery, flip the switch go up the hill and save the 36V juice to ride on the flats.


ebike4healthandfitness said:
One of the GMAC windings (I forgot if it was the 8T or 10T) matches up very very close to one of the Grin All axle motor windings (forgot which one).....so what you are saying is possible. But I think being able to switch 72v 25 amp to 36v 50amp on a single GMAC motor would make a better British Columbia (and non-california US moped) assuming it could made to switch voltage and amps on the fly. My only reservation is the MAC hub (which GMAC is based on) is not rated above 1000w by the manufacturer.
 
Yes there is, been thinking about it and someone posted up a resistor network for a throttle recently, that I will be copying. Using a 6 position rotary switch, or if I can find a 3 or 4 position (off-on-on-on-on) rocker switch which would be more ideal. Having resistors corresponding to the speed I want, with an off position to revert back to normal operation. As a safety I'd need to figure out how the throttle could disengage the switch, plus a hall sensored brake lever.
Its probably since the switch will be between the throttle and controller that any extra input from the throttle will disengage the software inside the controller but I need to wire it up and do it.


99t4 said:
markz said:
I just like cruise control because I go a constant speed but its hard to engage on bumpy pathways, hold throttle steady for 10 seconds. Then other times cruise is engaged when you dont want it.
CA provides a user selectable CC Set period out of several preset hold times (shortest is 3s, but you're right, the shorter set period is more apt to engage more unwanted CC sets). Isn't there a way to engage CC with a thumb switch or similar?
 
Markz, have you ever heard of a DeWalt flex volt battery?

It was battery that could change voltage and ah based on the tool it was plugged into.

For example, it could be a 60v 2ah for one tool and then switch to 20v 6ah for another tool.

Do you see where I am getting at? How changing volts and amps on the fly could be used to create multiple speed ranges at the same power from a traditional single speed?
 
ebike4healthandfitness said:
But I think being able to switch 72v 25 amp to 36v 50amp on a single GMAC motor would make a better British Columbia (and non-california US moped) assuming it could made to switch voltage and amps on the fly.
Having two speed ranges both at 1440 watts would overall efficient than one speed range that is twice as broad also at 1440 watts.
Didn't forum member DrkAngel do something very similar several years ago?
https://endless-sphere.com/forums/viewtopic.php?t=46353

That steampunk switchbox could be a cool feature on the right bike! (Chopper style?) :D
file.php
 
Had seen DrkAngel's switch. My batteries switch at the BMS. They come with a rocker switch to change from 36v 48ah to 72v 24ah. They still charge at 72v. Just don't know if they should be run in the 36v configuration. Run my 72v at 35a so 36v would be 70a.

Just a thought, the motor would get just as hot. Thought it would be better when riding at 10-15 mph for 87% efficiency. Would not want to make it to complicated.

Motor Simulator Dual Voltage
 
ebike4healthandfitness said:
I like the idea of 36v having half the speed of 72v, but with the same power.

So assume with phaserunner hitting 50 amps 36v would make 1440 watts assuming 80 percent efficiency. Likewise at 72v and 25 amps power would also be 1440w (if motor is 80 percent efficient).

36v at 50 amps for climbing and Regen down steep hills.

72v at 25 amps for flat ground or slight grades.

The ultimate (regen) moped set-up if it could be made to switch on the fly?
That's a lot of copper to add.

Be very careful of using this for regen. When you use the regen function on your controller, the FETs are switched on and off to generate that, so they are fairly efficient. When you are just running the motor over the base speed, the FETs are not being switched on and off - the current is just flowing through the body diode of the FET, which is very lossy. So the controller will see a lot more heating than normal.

If you really want two "gears" consider:

-Delta/wye switching. This isn't a 2:1 change (more like a 1.4 to 1 change) but it's effective. This requires a lot more high current wires coming out of the hub, though, and sometimes requires two sets of Hall sensors.

-A two speed hub. There's one hub out there (the Xiongda?) where you get one speed running the motor forward, and a different gear ratio when you run it backwards. It's low power though.
 
ebike4healthandfitness said:
Markz, have you ever heard of a DeWalt flex volt battery?

It was battery that could change voltage and ah based on the tool it was plugged into.

For example, it could be a 60v 2ah for one tool and then switch to 20v 6ah for another tool.

Do you see where I am getting at? How changing volts and amps on the fly could be used to create multiple speed ranges at the same power from a traditional single speed?

*sigh*

Now I see why Chalo is so grumpy - it must be rather irksome to see same ignorant banter repeated again and again and again ad nauseam!

Why cannot you people learn what is 'motor efficacy' actually is, what is 'copper' and 'iron' losses (and what is Ohm's law, is not not considered too hard for 15 year olds!), and why you cannot increase motor POWER by giving the motor more winds (actually this is the other way around!) or otherwise playing with KV rating of the motor (delta/vye switch included)?
There is just no replacement for giving the motor more mechanical advantage when it comes to getting more torque out of the motor w/o jacking up copper losses and/or burning up your motor, and there is no replacement for gears if you want high speed AND low end torque of the motor... that, or using more/larger motors, that is.
If you want a system that blasts two persons up a steep hill at high speed, this is a topic for e-motorcycle section of the forum, anyway.

And besides, why cannot you just make a 60-72v battery and exercise goddamn throttle control?! You'll still need a 72v capable *controller* after all! (Unless you plan to wire battery to motor directly, like some posters here seem keen on implementing... I wonder if this is trolling or serious)
If you cannot, add a button that 'turbo boosts' your *throttle* (like add/remove inline resistor or something), now that is not hard to do...
 
BalorNG said:
And besides, why cannot you just make a 60-72v battery and exercise goddamn throttle control?! You'll still need a 72v capable *controller* after all!

Yes, common sense would say that if using a 72v 50 amp controller why not just run as 72v 50 amp right? Then just practice throttle control as you say.

Problem is what you are suggesting would not be legal in most of the 50 states as well as British Columbia Canada.

In the US almost all the states have a law limiting mopeds to 2 horsepower (or even 1.5 horsepower in some cases).....so that is what a Rental moped will comply with.
 
BalorNG said:
Now I see why Chalo is so grumpy

I was thinking about pulling out my grumpy old man outfit this morning, but then I thought, who cares? People here do the damnedest things, and maybe sometime one of them will strike a vein and come back with something that really works. This doesn't happen often enough that I can think of an example right off hand, but in any case ... if you want to see the old men get grumpy, get onto some bicycle fad that's roping in millions of suckers.
 
BalorNG said:
And besides, why cannot you just make a 60-72v battery and exercise goddamn throttle control?! You'll still need a 72v capable *controller* after all! (Unless you plan to wire battery to motor directly, like some posters here seem keen on implementing... I wonder if this is trolling or serious)
If you cannot, add a button that 'turbo boosts' your *throttle* (like add/remove inline resistor or something), now that is not hard to do...

I use mostly KT controllers that let me limit the throttle to whatever PAS setting I've chosen. I find that riding around at 2 or 3 out of 5 usually does what I want, and I can use full throttle to cruise at a steady speed.
 
Here is a comparison I ran of a 72v GMAC 10T with 20 amp controller vs. 36v GMAC 10T with a 40 amp controller.

https://ebikes.ca/tools/simulator.html?motor=GMAC10T&mass=206&grade=6&batt=B7223_AC&axis=mph&motor_b=GMAC10T&batt_b=B3626_GA&mass_b=206&grade_b=6&bopen=true&cont_b=C40&hp_b=0&hp=0 (455 pound weight chosen to simulate two average sized americans (with clothes and shoes) on a 84 pound moped.

The 72v GMAC 10T with 20 amp controller wins (predictably) on flat ground up to around 4.5 percent grade. At 5% grade 72v with 20 amp ties with 36v with 40 amp. At 6% grade the 72v 20amp stalls (i.e. climbs at only .5 mph) but the 36v 40 amp continues to be able to climb steeper and steeper grades.

So yeah, it does appear this idea has merit if it could be made automatic/switch on the fly. (mopeds need to have automatic transmissions according to law in US and Canada (well at least in British Columbia, I haven't taken a look at the rest of Canada)).
 
ebike4healthandfitness said:
Here is a comparison I ran of a 72v GMAC 10T with 20 amp controller vs. 36v GMAC 10T with a 40 amp controller.

https://ebikes.ca/tools/simulator.html?motor=GMAC10T&mass=206&grade=6&batt=B7223_AC&axis=mph&motor_b=GMAC10T&batt_b=B3626_GA&mass_b=206&grade_b=6&bopen=true&cont_b=C40&hp_b=0&hp=0 (455 pound weight chosen to simulate two average sized americans (with clothes and shoes) on a 84 pound moped.

The 72v GMAC 10T with 20 amp controller wins (predictably) on flat ground up to around 4.5 percent grade. At 5% grade 72v with 20 amp ties with 36v with 40 amp. At 6% grade the 72v 20amp stalls (i.e. climbs at only .5 mph) but the 36v 40 amp continues to be able to climb steeper and steeper grades.

So yeah, it does appear this idea has merit if it could be made automatic/switch on the fly. (mopeds need to have automatic transmissions according to law in US and Canada (well at least in British Columbia, I haven't taken a look at the rest of Canada)).

What you want is easily implemented by a 'smart controller' where you can limit phase and battery currents independently.
This way you can have 40 (or 80 for that matter) phase amps at low speed (when your PWM is way below 100% hence *motor* voltage is way below 72v), but limit *battery* current so it does not exceed 1.5hp even at high speed using a controller/motor combo easily capable of double that.

However, using a speed limit is what this is *really* is about. When you are crawling steep uphill at 10 mph while carrying a ton of stuff and using 2+kw to do it, you are not hazard to anyone.

When blasting 50+ mph on a flat (made possible by same 2+ kw of power), a mistake can kill you and innocent bystanders to boot.

Downhill bicycles (that are cross motorcycles on a diet) can manage that, but a lot of typical bicycles are simply unsafe at those speeds. That's why there is a distinction between bicycles, mopeds and motorcycles, with each step there are stricter requirements on *mechanicals*.

Again, smarter controllers can do that (like e-bike vesc can give you 72v, 100A, but still limit your maximum speed to any number you want).
 
this thread is straying into a discussion on voltage-switching snd adjustable throttle limits. Perhaps those interested wouldn't mind if I split this off into its own thread? [No mention of solid state batteries for a while now?]

Years ago, we didn't have many choices for 72V batteries or high-amp cells.

The "go to" method that was doable was to take two 36V batteries and remove the BMS's, then series them for 20S / 72V. It works.

There are a variety of throttle controls that can be implemented, some of which are easy and cheap.

As far as using bicycle components for high performance...say what you will to protect us from ourselves, but...I doubt ES will change. There are other forums where power limits and speed limits for ebikes are embraced.

My 4-cylinder 1991 Toyota truck is absolutely unsafe at 100-MPH, and yet it is able to do that (tested once in the desert). The speed limit here is 75-MPH, and I am often passed by drivers doing 80.

I saw a Hellcat the other day with over 700 HP. I never once felt the urge to tell him he should limit his speed or power. However, I am a proponent of free speech, and any opinions on ebikes are welcome...
 
ebike4healthandfitness said:
Good thing is that the Tesla 4680 cell (which has silicon anode) can also charge faster than the 21700 cell.
Most of their publicity videos have very little information on the chemistry.
That is a bit disappointing ...
 
LewTwo said:
ebike4healthandfitness said:
Good thing is that the Tesla 4680 cell (which has silicon anode) can also charge faster than the 21700 cell.
Most of their publicity videos have very little information on the chemistry.
That is a bit disappointing ...

According to this article they use 6 to 10 percent silicon with graphite for the anode:

https://roskill.com/news/silicon-porsche-looking-at-silicon-in-ev-battery-anode/

"Tesla’s Model S and Model 3 use a silicon carbon anode material. Through adding 6-10% silicon-based material to synthetic graphite, its battery specific volume reaches more than 550mAh/g and energy density can reach 300Wh/kg. In the period to 2030, research suggests that some anodes may contain up to 30% silicon in automotive applications."
 
Well I thought I might do some layouts just to see how big a Tesla 4668 pack would be.

I have yet to see anything that approaches being an actual specification for the new Tesla 46x68 battery cell: voltage, capacity, dimensions, weight, contact size, charge/discharge curves, recharge cycles, etc ....
All we have thus far (oct 2021) is nothing more than meaningless research percentage numbers and pure marketing propaganda. All they have at this point is is a target diameter and length. Hard to begin designing actual production equipment with that little information. I think production may be further off than Elon Musk has predicted (Tesla is NOT known for hitting production dates anyway).

Then take into consideration that we will have wait until a number of new Tesla vehicles are crashed for a significant number of cells to be trickle down to the DIY consumers: I predict that I may be long dead and incinerated before either the 'solid state' or 'Tesla 4668' batteries change any hardware I use.
Tlesa 4668 layout-36 and 48 Volt strings.png

Edit:
I should have worded that differently:
"Assume 4.0 or less charge voltage".
 

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