ElectricMotorcycleForum.com
Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Doctorbass on October 15, 2017, 11:36:03 AM
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Hello guys, i made a video showing the test i made to find what current each 3.3kW units are drawing at various AC voltages
I decided to do that after i had trip some circuit breaker when using dual unit( 6.6kW total) on some charge station that operate at 208V and not 240V. My 2 units draw at 208V a total of 36A witch exceed the rated 30A max... witch cause problem with some charge station...
I also posted all the data here so you can select witch voltage you want to know the current or even the efficiency because i also measured and calculated the DC power output! (I did those measurement at 52% SOC)
Enjoy! https://youtu.be/vOG88zvmNN8 (https://youtu.be/vOG88zvmNN8)
Doc
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Wow awesome data Doc!!
With efficiencies between 90 and 96%, you could save a bit of energy just charging with the supercharger vs the onboard charger alone every night!! These ultra high frequency switching chargers are expensive, but their efficiency is outstanding!! Totally worth it. Also means if you only have a certain amount of power available from a charge station, more of that power goes into the bike, and less wasted as heat, meaning you actually charge at a faster rate.
I'd love to see more data at 215 and 220 VAC if you get a chance. Looks like it was above average high efficiency at 215 and below average at 220, and just wondering if those results repeat the same way. But not important, the general result is that it will pull 1600-1650 watts from the AC source from 80-180 VAC input, and what is incredible is almost exactly 3500 watts on the money from 185 volts all the way to 240 VAC!! Cool!! 8)
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Very nice. I will probably do something similar with my DeltaQ chargers, I just bought AC and DC power meters. It seems most chargers are constant current and that means the power increases as the battery charges. Is this true with the Diginow? Or does it output constant power so that the DC current is less when the battery voltage is high?
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Great info! thanks for taking the time to do this and sharing!
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Very nice. I will probably do something similar with my DeltaQ chargers, I just bought AC and DC power meters. It seems most chargers are constant current and that means the power increases as the battery charges. Is this true with the Diginow? Or does it output constant power so that the DC current is less when the battery voltage is high?
Thanks Keith,
I did that test at 52% SOC witch is an average or ( close to nomimal voltage of the battery) but i could repeat it at 25% and at 75% or different % request.
I guess you meant you understod that most charge are constant current AT THE OUTPUT right?.
because according to the data i have the power seem to remain the same.... i other words the regulation seem to be constant power "first" witch create the problem i have....
I would love to see those charger to draw steady 14.5 or 15A AC for voltages lower than 240V...
Because when you decide to use 2 of these the current draw MUST be 30A or less because many of the charge stations are on 208V ac and not 240V ac... and that test confirm that when these run on 208V ac they will exceed the common 30A current
Doc
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Wow awesome data Doc!!
With efficiencies between 90 and 96%, you could save a bit of energy just charging with the supercharger vs the onboard charger alone every night!! These ultra high frequency switching chargers are expensive, but their efficiency is outstanding!! Totally worth it. Also means if you only have a certain amount of power available from a charge station, more of that power goes into the bike, and less wasted as heat, meaning you actually charge at a faster rate.
I'd love to see more data at 215 and 220 VAC if you get a chance. Looks like it was above average high efficiency at 215 and below average at 220, and just wondering if those results repeat the same way. But not important, the general result is that it will pull 1600-1650 watts from the AC source from 80-180 VAC input, and what is incredible is almost exactly 3500 watts on the money from 185 volts all the way to 240 VAC!! Cool!! 8)
Terry witch data would you see at 215 and 220V? i can do the test on demand ;) just ask !
Doc
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Hey guys, we have a new firmware coming out that will be constant power constant voltage for better results. It will also have a very slow ramp and allow for Bluetooth control AND load sharing between the chargers.
Sent from my Nexus 6P using Tapatalk
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there's no bluetooth or serial input/output in the
modules that have been provided with the first SCv2,
so you won't get those features without buying or
building new control modules.
but yes, being able to control the bricks is really
good. i've been able to dial down the bricks'
current from when plugged into 240vac and
3-brick input exceeds my bike's 1C limit or to
dial down the charge rate when a station can't
deliver what it promises. (I don't have the
bluetooth like anton but I did add a the ramp up
and the manual override to my dev board.)
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With efficiencies between 90 and 96%, you could save a bit of energy just charging with the supercharger vs the onboard charger alone every night!!
Let's assume 20k miles ridden per year @ average 120 Wh/mile at the wall. 2.4 MWh is a lot of energy!
The chargers appear to be 91% to 95% efficient, per Doc's notes. It's really curious that there's such a large dip at 220V. Let's assume we're at 93% efficient on average, so we lose 168 kWh per year.
The data sheet for the GWP EVC1300 claims 92% efficient at 110V, 94% efficient at 240V. it probably would be useful to run a similar test with the OBC, but it doesn't seem like the Diginow is markedly more efficient. 20 kWh/year saved is no small amount - enough for another 170 miles of riding - but also not a ton.
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there's no bluetooth or serial input/output in the
modules that have been provided with the first SCv2,
so you won't get those features without buying or
building new control modules.
but yes, being able to control the bricks is really
good. i've been able to dial down the bricks'
current from when plugged into 240vac and
3-brick input exceeds my bike's 1C limit or to
dial down the charge rate when a station can't
deliver what it promises. (I don't have the
bluetooth like anton but I did add a the ramp up
and the manual override to my dev board.)
Is there a website with specs, prices, etc?
Sent from my Z982 using Tapatalk
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I guess you meant you understod that most charge are constant current AT THE OUTPUT right?.
Right. There are two separate dimensions to this as I see it. One is what you measured, AC power consumption versus AC voltage at a given SOC. The other is AC power consumption at a given AC voltage versus DC output voltage which varies with the SOC. A charger that outputs constant current will draw an increasing amount of AC power as the battery charges. If a charger outputs a constant power, then then AC input power would also remain constant as the dc voltage varies with SOC. Of course power becomes low when constant voltage output is reached.
So either CC/CV or CP/CV charging could be done. Which one is better for the battery? CP would charge faster at low SOC than CC for the same maximum power. I don't know how the internal resistance of the battery varies with SOC but I'm sure it does. That would affect heating due to I^2R. There also might be other considerations with chemistry and such that would influence this choice. But disregarding the battery, it seems that constant power makes more sense. The AC input power required is then fixed and known, and the charging rate in kWh/h is constant rather than increasing with SOC. Right? Or does anyone really know?
BTW the legend for your chart shows five variables, but I only see three lines. Volts out is almost constant so unimportant and current out is not shown although it seems to have basically two constant values. So what I was asking is would the current out values stay constant or vary with SOC?
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Keith,
I've been confirmed that the way these "similar as Elcon "unit work depend mostly on witch firmware these have.
These suplied by Diginow have special firmware for the Zero.
From my understanding The firmware can only control the DC output witch affect the AC input btw. The output is constant power actually for 3.3kW so the DC current is not constant.. it will vary depending on the SOC o fthe battery.. if voltage is higher, current is lower... That's why i measured all the value only at one SOC and made all these in very short period to not have the SOC to vary so much so the ratio of Volt vs curret remain teh same.
In summary: My SCv2 are:
- constant output power
- input AC curent vary with input voltage.
- input power vary a little bit with Ac voltage input due to efficiency curve not linear
- Firmware monitor and control DC output.
- Hardware limit the max input power
Doc
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Thanks for the clarification Doctorbass. I still wonder about which method is best CP or CC. I think CP means constant charge rate in energy v. time so it seems right, while CC means the rate gets higher near fully charged which means the battery is hotter right when you are going to use it. But is there a reason to charge more slowly at low SOC as CC does? Or is this just a side effect of a simple design that limits current to a constant value? Since the battery voltage doesn't change by very much, it isn't a huge difference but it would matter if trying to get the quickest charge while staying below a BMS power limit. Or is it staying below a current limit? Hmmm. Somebody knows...
Anyway I found a variac to borrow so I will collect the same data for the DeltaQ charger which I think is constant current. That means the AC input power will vary with both AC voltage and battery voltage so it will require multiple graphs.
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Guys, these are not elcons. They just use the same housing that Elcon and a few other companies use. We all have them built by the same company in china for us because they are the most reliable.
Dr. bass has earlier prototype units with unique hardware and software so the data provided is slightly different than the production units.
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Also about CC vs CP
CC is variable power out like you described which means it is variable power in as well. If a station can deliver 32A at 208v that's 6.5kw ish which means optimal output would be around 6.5kw so CP is ideal when limited by the ac power source.
If you have more power avaialable than the charging unit can deliver then CC is ideal to get the most.
Since we can deliver more power than some stations can give us CP is ideal. With the ability to control the power via your smart phone.
Sent from my Nexus 6P using Tapatalk
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> Is there a website with specs, prices, etc?
Brandon, get your website back online!
In the meantime, Clay, looks like he's got some stuff at
https://www.facebook.com/digiNowInc/
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Or get at least an ''Under construction'' page instead of a 404.
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Here is the amp draw and efficiency data for the DeltaQ Zero Quick Charger. It is constant current out, about 8.8 amps DC, so the power input varies with both AC voltage and DC output voltage depending on the SOC. No surprises, performance is very consistent, efficiency is high with slight drop off at low AC voltages.
This was going to be easy, my arduino was programmed to measure and collect all the data and send it to serial out so it could be plotted. But it bricked, my second dead Nano, so I did this the old school way, by hand. I wish I knew what killed it, my guess is a switching transient, lots of power nearby. Back to the drawing board.
Here's the spreadsheet https://docs.google.com/spreadsheets/d/1qtNmazUpdlHOjmGN-p3wvUzM3L8HxQlRaM5vuaqWkyI/edit?usp=sharing
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Doctorbass, you probably want to take a look at my recent post. I'm honestly surprised that you as an expert with tons of experience and a huge variety of charger builds didn't have the idea to just order those chargers yourself in China. Would have saved you at least 2000$. What did you expect to be so special about the DigiNows?
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I think he got a deal, Josh : - )
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Doctorbass, you probably want to take a look at my recent post. I'm honestly surprised that you as an expert with tons of experience and a huge variety of charger builds didn't have the idea to just order those chargers yourself in China. Would have saved you at least 2000$. What did you expect to be so special about the DigiNows?
I wanted to ignore this and don’t want to derail this thread, but I think you should spend a little more time learning from these experts before insinuating that Doc or Diginow are making mistakes or doing something wrong. They both have done great things for this and other online communities.
Thanks for putting these efficiency numbers together guys. It’s always nice to see real world data!
Sent from my iPhone using Tapatalk
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I think he got a deal, Josh : - )
Not so...
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Doctorbass, you probably want to take a look at my recent post. I'm honestly surprised that you as an expert with tons of experience and a huge variety of charger builds didn't have the idea to just order those chargers yourself in China. Would have saved you at least 2000$. What did you expect to be so special about the DigiNows?
Use your cheaper units like you think you will eventually find out yourself....You said "inferior product" regarding the Diginow did you?.. Good to see you dont have any doubt about what you bought. Saving money compare to risk of ruining or badly affect capacity of a 12000$ monolith battery from Zero due to bad/incomplete charging profile is different reality. Charging is not only puting volt and amp...
reality of Bulk charging is one thing, connecting and leaving your charger alone with safety and all protections and care of cells for years is another. i bought paid ansd choosed the Diginow to also review it for the rest of the community as a Zero motorcycle approoved charging solution.
Doc
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[...] charging profile is different reality. Charging is not only puting volt and amp...
reality of Bulk charging is one thing, connecting and leaving your charger alone with safety and all protections and care of cells for years is another. i bought paid ansd choosed the Diginow to also review it for the rest of the community as a Zero motorcycle approoved charging solution.
Doc
Just curious: In another thread you mentioned an Elcon power supply for charging that can do 116.4V and 2kW. Do you also need to adjust the charging profile with these, or are they already optimized for the Zero?
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[...] charging profile is different reality. Charging is not only puting volt and amp...
reality of Bulk charging is one thing, connecting and leaving your charger alone with safety and all protections and care of cells for years is another. i bought paid ansd choosed the Diginow to also review it for the rest of the community as a Zero motorcycle approoved charging solution.
Doc
Just curious: In another thread you mentioned an Elcon power supply for charging that can do 116.4V and 2kW. Do you also need to adjust the charging profile with these, or are they already optimized for the Zero?
Great observation Neuer_User and it deserve a good response too!
Those are not Elcon but Eltek brand. Eltek is a world wide supplier of server rectifier and solar and smart grid power charging/battery management solution.
Please understand that when you have the experience you can charge a battery with any power supply that does CC-CV IF and only IF you know what you are doing.
It's called Bulk charging, but you have to keep an eye on it while it charge... that's not the same as having a plug that you simply connect to the wall socket and leaving it connected...
Bulk charging require knowing the battery chemistry, how the BMS of that battery work and also know the limitation of the battery and charging profile.
I do both... I bulk charge and also like to have a charger that does everything including the care of the battery that i dont have to bother with.
It is VERY important to understand the difference between both methods and to have experience of charging lithium battery. Personally i have 12 years of experience with that and have my own testing lab for lithium battery.
Doc
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Hello Doc,
I am a newbie about EV and I am trying to learn about charging. I have some questions.
If there is a BMS, isn't it opening and closing the contactor to modulate the charging current of the bulk charger
to effectively make it a smart charger? I was reading about BMS and couple of ways to control the balancing of the cells and
one way is to turn on/off the charger. The other way is to instruct the charger to go low current with CAM control or even analog signaling.
For sure there are more ways and I might got it wrong also :).
Thanks for your help,
Giacomo
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Hello Doc,
I am a newbie about EV and I am trying to learn about charging. I have some questions.
If there is a BMS, isn't it opening and closing the contactor to modulate the charging current of the bulk charger
to effectively make it a smart charger? I was reading about BMS and couple of ways to control the balancing of the cells and
one way is to turn on/off the charger. The other way is to instruct the charger to go low current with CAM control or even analog signaling.
For sure there are more ways and I might got it wrong also :).
Thanks for your help,
Giacomo
Hi
That's a good question and it deserve a good response! ;)
Cheap Ebike ( electric bicycle ) chargers work that way, they trigger ON and OFF the charger to not overcharge and keep cell voltage below their limit, until all cells have reached their max voltage.. then current slow down to ideally C/20 with the CC-CV feature of the charger.
Some charger also have small current that will remain ON but that is under what the bleeding resistors current draw to help accelerating balancing state.
The BMS on electric car and the Zero are more complex and way smarter. They have very special algorithm that take account of the temperature, SOC, age and cycles of the battery to adjust current and enable or not. They even datalog all events in the processor memory.
The Contactor of the Zero drivetrain is not made to trigger ON and OFF at the rate a BMS would require to balance cells. Instead, The OEM Zero chager current is electronically controlled vis CANbus.
But if you BULK charge a Zero thru the controller DC connections or any other DC input the Zero have, it will remain protected against abnormal value and even if one or more limit( voltage, temp, current etc) is reached the contactor will open to cut the DC charging current input and keep the battery protected.
I suggest reading on the Zero unnofficial manual page to get more info.
Doc
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it make sense :). I will read more and come back with more questions .... :p
Thanks,
Giacomo
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Opening the contactor under load should be avoided, I think, Giacomo.
High voltage arcs, wears out switches early.
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Opening the contactor under load should be avoided, I think, Giacomo.
High voltage arcs, wears out switches early.
You are right.
Live make or break on contactor reduce his life alot. In fact when charging the voltage difference between the battery and the charger is minimal as the charger try to push to 116.5V and if the battery is at 50% soc, it will have 102V so the diff is only 14.5V, not bad at all.. and will not cause severe arc unless current is very high!
Doc