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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Zelidar on September 29, 2023, 02:34:46 AM

Title: Zero App & Average Efficiency
Post by: Zelidar on September 29, 2023, 02:34:46 AM
The Zero app indicates me 70600 km on the odometer for a total of 3543 kWh. That translates to 50.18 Wh/km. On the other hand that same app calculates and displays an average efficiency of 80 Wh/km (which seems more realistic btw) but that is 46.15% more.

80 Wh/km implies a total energy consumed of 5648 kWh. That could be what was put into the chargers, and 3543 kWh would be what was drawn from the battery and put in the motor, does that make any sense? That would mean a pretty terrible overall energy efficiency of 62.73%.

Given that (roughly) Overall Efficiency = Charging Efficiency × Battery Efficiency × Motor and Drive Train Efficiency, that suggests an efficiency of around 85% at each stage (0.85x0.85x0.85=0.63).

What do you think?

Zero App on Android V2.8.1, OS Version 13.
Title: Re: Zero App & Average Efficiency
Post by: Specter on September 29, 2023, 11:14:26 PM
Overall energy efficiency of 63 percent would actually be pretty kick ass.
Switching energy states is not an easy or efficient task overall in general.

A/C switching power supplies, which is what is used for the most part, when charging with AC are NOT very efficient.  You can count on up to 20 percent loss ball park.  So yes to put 20 KW into a 20 KW battery .. you will burn close to 24 KW of AC coming into the charger / rectifier. 

Even if you CCS charge it, and put direct DC into your bike,  it's still coming from AC, and the switching / burn is happening in the charger outside the bike, instead of the one inside the bike.

The only way you'd truly boost your overall efficiency would be to charge it directly with DC, get a solar array and run it at 330 volts and it should charge it with very little loss.   Then again, what is the overall efficiency of panels, vs say an LM 5000 LE/EX ... whatever iteration they are on now, running combined cycle  or a super hyped 7FE for close to 50 percent efficiency and that is FANTASTIC efficiency at only 50 percent.

Efficiency is a very cloudy at best number in this case.  Kind of like Estimated Range.  It's more a feel good number than anything actually truthful or useful.

Aaron
Title: Re: Zero App & Average Efficiency
Post by: TheRan on September 30, 2023, 02:06:33 AM
The efficiency of the chargers used in Zeros is like 90-95%, depending on the input voltage. The drive train is also 90%+ efficient. Motor efficiency can of course vary by load but from what I could find with a quick look 85% to the high 90s seems like a good number. Worst case scenario that gives ~93% efficiency from the charger to the battery or at 6kW potentially about 420W of heat at least being produced by the battery, seems a bit high to me. Best case scenario and it's around 74% or over 1.5kW of heat which obviously isn't happening. I would say the numbers in the app are probably at least a little bit off.
Title: Re: Zero App & Average Efficiency
Post by: Bodo on September 30, 2023, 03:18:30 AM
Both ZMC apps are novelty gadgets; I don't think they are meant to be serious.
Title: Re: Zero App & Average Efficiency
Post by: remmie on October 01, 2023, 05:26:03 PM
Quote from: Zelidar on September 29, 2023, 02:34:46 AM
The Zero app indicates me 70600 km on the odometer for a total of 3543 kWh. That translates to 50.18 Wh/km. On the other hand that same app calculates and displays an average efficiency of 80 Wh/km (which seems more realistic btw) but that is 46.15% more.

80 Wh/km implies a total energy consumed of 5648 kWh. That could be what was put into the chargers, and 3543 kWh would be what was drawn from the battery and put in the motor, does that make any sense? That would mean a pretty terrible overall energy efficiency of 62.73%.

Given that (roughly) Overall Efficiency = Charging Efficiency × Battery Efficiency × Motor and Drive Train Efficiency, that suggests an efficiency of around 85% at each stage (0.85x0.85x0.85=0.63).

What do you think?

Zero App on Android V2.8.1, OS Version 13.

I bet there is a conversion of kilometers to miles between those 2 figures :)
50.18 *1.609 = 80.7 So it seems likely.

try to set your locale from kilometers to miles (or the other way around depending on where you live) and see if the 2 figures match up. If they match up, the conversion is (wrongfully) omittedin 1 of the 2 value, or maybe even applied twice by mistake.
Title: Re: Zero App & Average Efficiency
Post by: Zelidar on October 02, 2023, 02:50:50 PM
Quote from: remmie on October 01, 2023, 05:26:03 PM
50.18 *1.609 = 80.7 So it seems likely.

Yes, in this context that is too close to be wrong, why haven't I thought of that? Thank you Remmie.

Quote from: Specter on September 29, 2023, 11:14:26 PM
Overall energy efficiency of 63 percent would actually be pretty kick ass. Switching energy states is not an easy or efficient task overall in general.
Efficiency is a very cloudy at best number in this case.  Kind of like Estimated Range.  It's more a feel good number than anything actually truthful or useful.

Nonetheless, some of my EVSE chargers are able to accurately display the AC kWh which enters the bike's plug. On the other hand I expect Zero to know how much total power (kWh) is delivered to the motor by the inverter. Based on these numbers, an average efficiency should be usable, even if not accurate.

Quote from: TheRan on September 30, 2023, 02:06:33 AM
... Best case scenario and it's around 74% or over 1.5kW of heat which obviously isn't happening. I would say the numbers in the app are probably at least a little bit off.

Also surprised by the poor value, especially given that a Tesla model 3 is twice that but so much heavier.

Metric / VehicleTesla Model 3Zero SR/F Motorcycle
Energy Consumption (Wh/km)16080
Vehicle Weight (kg)1,611226
Passenger Weight (kg)Varies (Assume 5 passengers * 75 kg = 375 kg)150 (2 passengers * 75 kg)
Total Weight (kg)1,986376
Passenger Capacity52
Energy per Passenger (Wh/km per passenger)3240
Energy per Kilogram (Wh/km per kg)0.09930.2128

Quote from: Bodo on September 30, 2023, 03:18:30 AM
Both ZMC apps are novelty gadgets; I don't think they are meant to be serious.

Yep, just like those notifications, that has only worked a couple of months in 2020 for me.
Title: Re: Zero App & Average Efficiency
Post by: Specter on October 02, 2023, 07:10:41 PM
Also don't forget, the plug is showing how may KW it's feeding the charger, the bike may be showing how many KW is being fed to the battery.  There is some conversion loss, and maybe a fan or two as well sucking some power, which may throw it off a bit.

I seen this with my DC fast charger .vs. what the wall is saying it is putting out and what the Ribelle is seeing.  Turns out the wall amps is wall amps, at 240 volts,  the ribelle's amps are at 300 ish volts, whatever the battery is at, so ya will show less, but the KW are very close from charger to bike.  When I run AC charging now, there is a decent difference.

Aaron
Title: Re: Zero App & Average Efficiency
Post by: SwampNut on October 03, 2023, 12:03:27 AM
The app and my dashboard disagree on the lifetime efficiency.  I have no idea how to make the dash update itself.  It has been stuck on the same reading since I bought it with 42 miles on it (new demo bike).  So it makes me wonder what the validity of the numbers is all around.