ElectricMotorcycleForum.com
Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: NEW2elec on August 08, 2018, 10:11:27 PM
-
For some time now people have stated that fast charging is the bottle neck for long distance riding, being the only real option to limited size battery space on motorcycles.
I also think all would agree DC fast charging is superior to AC in all but Tesla superchargers. CHAdeMO and CCS being the two major players in the U.S. with others out there or soon to arrive.
As some of us remember Zero used CHAdeMO on their 2013 bikes with limited success due to the chargers not being able to lower their voltage to Zero's 117V and Zero dropped the option soon after.
Energica uses DC charging since they use a 450V (approx) system with no problem.
So that got me thinking with my limited electronics brain with simple series and parallel wiring.
What if the bricks in a Zero could be set up to be switched to a series circuit giving them 460V to accept the DC charging.
Would the bricks need two sets of terminals so a manual switch could open the parallel operating circuit and closing the series charging circuit?
As always I accept the possible embarrassment of having my ideas shot down or corrected and this one seems simple enough that others could have used it if it could work but I wanted to put it out there and see what the big boys think.
-
Far from a stupid question, it's been proposed and discussed. There are very real problems with doing that, however. First, it's a very significant change to the battery topology, so it would be back to the drawing board for a complete re-design. We couldn't do that at home, Zero would have to do it.
But perhaps even a bigger problem is just finding devices to do the switching. Full charging current (100A?) would have to be supported in charging mode, and full load current (660A+) in run mode. It would require giant relays, giant MOSFET switches or both. Neither of those are really practical, given the expense, space they would take up, and heat they would dissipate.
Anyhow, even if you did work it all out, you're really chasing a technology in its decline with CHAdeMO. Here in the states it never really did catch hold, and it doesn't look likely to. CCS has a lot better chance, but market penetration still isn't very good. I'm not anxious to jump on that boat just yet.
-
For some time now people have stated that fast charging is the bottle neck for long distance riding, being the only real option to limited size battery space on motorcycles.
I also think all would agree DC fast charging is superior to AC in all but Tesla superchargers. CHAdeMO and CCS being the two major players in the U.S. with others out there or soon to arrive.
As some of us remember Zero used CHAdeMO on their 2013 bikes with limited success due to the chargers not being able to lower their voltage to Zero's 117V and Zero dropped the option soon after.
Energica uses DC charging since they use a 450V (approx) system with no problem.
So that got me thinking with my limited electronics brain with simple series and parallel wiring.
What if the bricks in a Zero could be set up to be switched to a series circuit giving them 460V to accept the DC charging.
Would the bricks need two sets of terminals so a manual switch could open the parallel operating circuit and closing the series charging circuit?
As always I accept the possible embarrassment of having my ideas shot down or corrected and this one seems simple enough that others could have used it if it could work but I wanted to put it out there and see what the big boys think.
"DC fast charging is superior to AC " I don't get this comment. Batteries being charged are always charged with DC, at the batteries. The source of the DC is (practically) always AC. That is, AC from the power network is converted to DC. The charger can convert AC to DC in many ways but it always ends as DC.
"What if the bricks in a Zero could be set up to be switched to a series" Series or Parallel, the watt-hours are the same. Series connection has less current, higher voltage, but same wattage so in the end either way works just as well to get energy into the batteries.
-
If you want to fill up an ICE bike you don’t need to bring the pump with you. The pump sits at the gas station.
I don’t want to drag along my own AC to DC converters when DC is already available at the station.
Please just someone make the necessary communication electronics between the DC chargers and the Zero bike.
-
I also think all would agree DC fast charging is superior to AC in all but Tesla superchargers.
Tesla Superchargers are DC.
-
There has been plenty of news about thousands of charging stations planned to be constructed all over California both by utility companies, like PG&E who plan to charge rate payers for the infrastructure (and take a percentage off the top as profit), and companies that have been bad, like VW and are installing charging stations instead of paying a fine for their bad deeds. But all I ever hear about are L2 stations and not a peep about DC charging. So it sounds to me like, unless you own a Tesla or want to drive from one Leaf dealer to another, you will be on the long slow road when it comes to long distance EV travel. ::)
-
Thanks for the replies so far.
To clear up a few things:
T.S. Zarathustra: Yes it all turns into DC before it goes to the battery but DC fast charging was what I was getting at. The J1772 charge plug works at about 6kW where as a Tesla super charger (yes Erasmo your right, I remembered it after I wrote it) charges at 120kw. More power less time to charge. But if you don't get the voltage up you have to up the amps which would take huge cables and make insane amounts of heat. Wiring the four 117 volt Zero bricks in series gets the voltage up to the 460V. The wattage is much higher in DC fast charging. Energica lists 30 mins from 0-85% and around 3 hours for level 2 AC charging.
olle.eriksen2: I said the same thing only I used the term oil refinery not gas pump in an old post. :)
Doug S: So how does Energica do it? The only difference I see is the operating voltage. They achieve it by having cells in series. I don't know how many "bricks" they have in parallel but not too many I would guess with their lower range.
-
There has been plenty of news about thousands of charging stations planned to be constructed all over California both by utility companies, like PG&E who plan to charge rate payers for the infrastructure (and take a percentage off the top as profit), and companies that have been bad, like VW and are installing charging stations instead of paying a fine for their bad deeds. But all I ever hear about are L2 stations and not a peep about DC charging. So it sounds to me like, unless you own a Tesla or want to drive from one Leaf dealer to another, you will be on the long slow road when it comes to long distance EV travel. ::)
L2 stations and DC are different worlds. Before you can think about distance travelling you need to make sure that the average EV-commuter has a place to charge at work or at night, and with power up to 22kW you can pretty much fill every EV on the market during your workday or while you sleep.
DC coverage comes after that, but until 2014-ish there still was a bit of a standard war on what plugs to use, now the dust has settled and Chademo and CCS emerged as winners. Two plugs on a single station aren't a problem, the main cost of the station is in the AC-DC converter.
I'm curious why they opt to charge rate payers for DC fast charging stations instead of letting the market figure it out?
-
Doug S: So how does Energica do it? The only difference I see is the operating voltage. They achieve it by having cells in series. I don't know how many "bricks" they have in parallel but not too many I would guess with their lower range.
I can't speak very authoritatively about Energica, but as far as I know their system is just designed to run at a higher voltage, so they don't have to reconfigure anything to charge at a higher DC voltage. Zero consciously made a decision early on to design their motors to run on a "not quite lethal" voltage, which is a blessing for their service people, but it's made them an outlier in the EV world, which has caused some problems in terms of DC charging. In theory, CHAdeMO is supposed to work down to 50V, so it should work just fine, but the charging stations don't comply with the full spec range and won't charge a "low-voltage" system like the Zero's.
-
There has been plenty of news about thousands of charging stations planned to be constructed all over California both by utility companies, like PG&E who plan to charge rate payers for the infrastructure (and take a percentage off the top as profit), and companies that have been bad, like VW and are installing charging stations instead of paying a fine for their bad deeds. But all I ever hear about are L2 stations and not a peep about DC charging. So it sounds to me like, unless you own a Tesla or want to drive from one Leaf dealer to another, you will be on the long slow road when it comes to long distance EV travel. ::)
L2 stations and DC are different worlds. Before you can think about distance travelling you need to make sure that the average EV-commuter has a place to charge at work or at night, and with power up to 22kW you can pretty much fill every EV on the market during your workday or while you sleep.
DC coverage comes after that, but until 2014-ish there still was a bit of a standard war on what plugs to use, now the dust has settled and Chademo and CCS emerged as winners. Two plugs on a single station aren't a problem, the main cost of the station is in the AC-DC converter.
I'm curious why they opt to charge rate payers for DC fast charging stations instead of letting the market figure it out?
The utility companies and bad boys are building L2 AC charging stations, not DC fast charging stations, I assume because they are much cheaper to build and install and everyone is going for numbers, not fast charging or convenience for travelers. This entire thing is political in California. Most of the utility charging stations will be located in "under-served" neighborhoods - where the residents can't afford an electric vehicle (but will likely vandalize the equipment). And utility customers will end up paying for these AC slow-speed charging stations, which will not be maintained and will soon become small monuments to the state of the early EV concept, just like the photo in the recent Motorcycle.com Energica SS9 review and the one installed at the back of my local Safeway store's truck dock area, which took two years to turn on, worked for one year and seems to fallen into disrepair already. :(
-
Thanks for the replies so far.
To clear up a few things:
T.S. Zarathustra: Yes it all turns into DC before it goes to the battery but DC fast charging was what I was getting at. The J1772 charge plug works at about 6kW where as a Tesla super charger (yes Erasmo your right, I remembered it after I wrote it) charges at 120kw. More power less time to charge. But if you don't get the voltage up you have to up the amps which would take huge cables and make insane amounts of heat. Wiring the four 117 volt Zero bricks in series gets the voltage up to the 460V. The wattage is much higher in DC fast charging. Energica lists 30 mins from 0-85% and around 3 hours for level 2 AC charging.
olle.eriksen2: I said the same thing only I used the term oil refinery not gas pump in an old post. :)
Doug S: So how does Energica do it? The only difference I see is the operating voltage. They achieve it by having cells in series. I don't know how many "bricks" they have in parallel but not too many I would guess with their lower range.
I first want to point out that fast charging damages the batteries. Please read through this blog from Qnovo, a battery charging solution company. https://qnovo.com/category/fast-charging/ That graph is quite scary if you have been fast charging your bike. :o
The charger in your bike is not accurately compared to a pump for fuel. The main work of the charger is to control, limit, and smooth the power, that is pushed from the grid, into the battery. Fuel pump pushes fuel into the tank, sucking it from another tank. Converting AC to DC usually uses less than 10 components inside the charger.
Zero gets away with using relatively low voltage because of the relatively low power demand of the bike. If they used higher voltage, safety would be compromised, they would have to use less efficient electronic components, thicker and/or more expensive insulation, and the design would be more expensive and bulky, with wider spacing between circuits. (Of course, life is nothing but compromises. :D )
To get realistic comparison, kWh charging should always be compared between equal size batteries. The 10-15 kWh battery in Zero should not be compared to the 100 kWh battery in Tesla.
-
There has been plenty of news about thousands of charging stations planned to be constructed all over California both by utility companies, like PG&E who plan to charge rate payers for the infrastructure (and take a percentage off the top as profit), and companies that have been bad, like VW and are installing charging stations instead of paying a fine for their bad deeds. But all I ever hear about are L2 stations and not a peep about DC charging. So it sounds to me like, unless you own a Tesla or want to drive from one Leaf dealer to another, you will be on the long slow road when it comes to long distance EV travel. ::)
Seriously, studies have shown the average American takes ONE road trip a year, and 80% of those are within their home region. Long distance travel is a myth. Gen 2 Evs are capable of making regional trips without enroute charging. Destination L2 chargers are more than adequate.
-
There has been plenty of news about thousands of charging stations planned to be constructed all over California both by utility companies, like PG&E who plan to charge rate payers for the infrastructure (and take a percentage off the top as profit), and companies that have been bad, like VW and are installing charging stations instead of paying a fine for their bad deeds. But all I ever hear about are L2 stations and not a peep about DC charging. So it sounds to me like, unless you own a Tesla or want to drive from one Leaf dealer to another, you will be on the long slow road when it comes to long distance EV travel. ::)
Seriously, studies have shown the average American takes ONE road trip a year, and 80% of those are within their home region. Long distance travel is a myth. Gen 2 Evs are capable of making regional trips without enroute charging. Destination L2 chargers are more than adequate.
But they do have to be working and not be occupied by an IC SUV. In CA there is no state law that I know of requiring charging stations to be occupied only by an EV using the parking space for charging. A private property owner might be able to call a tow company to tow the car if the location is properly marked, but if parking spaces in the area are at a premium, watch out. There is a very popular grocery store in my daughter's town that has three charging stations and they are used quite frequently by IC cars to park when the lot gets full. Apparently everyone knows that the store does not enforce the parking restrictions. Plus, the store likes their big SUV customers and doesn't want to do anything to cause them grief. (The bigger the car the more groceries they buy.) ;)
-
Okay T.S. Zarathustra, man I have to say not only are we not on the same page it's like your in a different library. I wanted to have a way to have the best of both bikes. Zero's 117 volts operating system gives us the most range for the weight and battery size of any electric motorcycle.
The drawback is having to buy 2-3 thousand dollar charging units to be able to charge up 80 more miles of range in a couple hours.
The theory was a switch to give you high voltage "only" for DC fast charging.
The fact that we don't need to fast charge all that often makes the cost of the fast charges that much harder to swallow.
And quickly, the analogy of the oil refinery to the AC chargers is both have to convert something that is basically useless to us into something we can use. If there is an option to get it in the form we need from the beginning, and there is, that's a better option.
Now as for charging stations we need to be forward thinking. The free little 6kW chargers some shops and hotels and businesses put out early were little green crumbs to get wealthy EV owners to choose them. Imagine if 80% of all the cars in a parking lot are electric with one plug.
Take the 10-15 miles of range that you can get in an hour of charging a car with J1772. What is that worth to you? Is it worth $5? If it is the charging station would only make $120 a day at most.
Now make it much quicker more like the gas station model.
Now you can get 50-80 miles range in 20-30 mins. That could be worth paying for and the shorter time gets more higher paying customers through.
The 6kW J1772 chargers work for home use and at work for now if there are only a few EVs at work needing to charge.
For longer trips and commutes there will need to be a quick "gas station" model solution.
-
Come over to my library, we have cookies. :D
At the end it is always the cells (in the battery) that limit the charging speed. To safely charge most of current cells, you need to keep the current below certain amount. It does not matter how many volts you have, if you charge too fast you will reduce the life of the battery. It is usually considered on the limit of safe charging to charge the cell to 90% in one hour.
Now, to confuse things further. :) If you would somehow be able to fit bigger batteries or increase efficiency (or do a deep study into hypermiling) you can get further with shorter charge time. An example: You have vehicle that can get 100 miles, using 10 kWh, and has 10 kWh battery. At safe charge you can charge roughly 90 miles of range in an hour. If you reduce the power consumption to 100 miles, using 5 kWh, you can charge 90 miles of range in half an hour. If you also double the battery size to 20 kWh you can suddenly charge 90 mile range in 15 minutes. The holy grail, in my eyes, is not high speed charging, but better efficiency and bigger batteries.
-
There's no particular merit to high voltage over high current, or vice versa. You can design an electric motor to run on higher voltage at lower current, or lower voltage at higher current, and both motors will work fine. Battery cells can also be connected in series/parallel arrangements with higher voltage and lower amp-hour capacity, or lower voltage and higher amp-hour capacity, giving the same energy storage capacity, and either of those will work fine. Neither configuration has any inherent advantage over the other. Neither is guaranteed to get you more range, or save weight, or package better, or have any other clear-cut advantage.
Each configuration does have small advantages and disadvantages. The high-voltage configuration, since it uses less current to deliver the same power, might weigh a bit less because the wiring doesn't have to be as heavy-duty. You might save a couple of pounds of copper by using smaller-gauge wiring. (But maybe not, since it might require heavier insulation to be safe at the higher voltage.)
Lower voltage is definitely safer. I imagine most of us Americans have been zapped by 115VAC line voltage, which isn't pleasant but it generally doesn't do any permanent damage. The Zero's 116VDC battery would do about the same if you inadvertently came into contact with it. But the 350VDC Tesla battery pack could do some serious damage, could even kill under the right (wrong) circumstances. My understanding is, that's why Zero designed for lower voltage and higher current -- it's demonstrably safer, to service personnel and rescue personnel in the event of an accident.
As far as fast-charging harming batteries, that used to be pretty universally true. But battery technology is moving forward very fast, and there are a lot more fine points to the story now. Li-ion batteries have a lot longer lives, and can tolerate much higher charge and discharge rates than they could even just a few years ago. This study:
http://www.greencarcongress.com/2014/09/study-finds-rapid-charging-and-draining-doesnt-damage-lithium-ion-electrode-as-much-as-thought-.html
seems to show that the damage to Li-ion cells by fast charging isn't as great as we once thought, or maybe as it once was. Granted it's a four-year-old study, but the point is we just don't know everything about the newest generation of batteries yet. I seem to recall seeing a study with similar conclusions about fast-charging Teslas a while back, but I can't find it now.
BTW, this article:
https://insideevs.com/lets-look-at-tesla-model-s-x-battery-degradation/
shows that Tesla, in the real world, is managing to provide some outstanding battery life, presumably with a mix of supercharging mixed in. These ain't your daddy's batteries.
-
Well put Doug.
As for fast charging (sorry), there are many different chemical mixtures and battery management systems. Some rare more sensitive for fast charging than others. The reason fast charging damages batteries (that Lithium Ions don't go into the electrode, but get stuck on the surface during fast charging) was explained to me in a way that makes me still follow the rule to not fast charge unless necessary. I also avoid storing fully charged or nearly empty batteries.
-
I like cookies. Hmmmm
It's all a bit frustrating because the "rules" seem to keep changing. I read, saw reports the fast charging can even be good for Li-ion because it reduces the build up of dendrites. So we'll have to agree the jury is still out on the effects.
I for one feel better about my little quiq charger helping out so my onboards don't have to work for 5 or 6 hours.
Now I have heard the basic specs for the new electric Porsche Taycan and they seem to support the idea for high voltage.
800 volt system (yeah that'll kill ya)
300ish miles of range
3ish seconds to 60mph
600 HP
15 min recharge.
That's game changing in my eyes. Of course my eyes are watering at the price but you can't get it all.
Doug my understanding (limited) was that basically high voltage gave you speed for an electric motor and amps gave you your run time or range in our case. I wouldn't want to give up my range so that got me thinking of a way to have both. Can't have my cake and eat it too I guess.
-
And from my last comment here is the new Porsche:
https://www.autoblog.com/2018/08/15/porsche-taycan-ev-prototype-frunk-video/?ncid=edlinkusauto00000021&yptr=yahoo
-
And from my last comment here is the new Porsche:
https://www.autoblog.com/2018/08/15/porsche-taycan-ev-prototype-frunk-video/?ncid=edlinkusauto00000021&yptr=yahoo
800 volts (and who knows how many amps) ought to get your attention when working around that vehicle. But then at the prices that Porsches sell for, that is nothing that I will be worried about. ;)