ElectricMotorcycleForum.com
General Category => General Discussion => Topic started by: domingo3 on April 26, 2019, 12:08:10 AM
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For the zillionth time, I've seen EV enthusiasts mixing up kW and kWh. This time in particular, it was on FaceBook, which I try to avoid getting sucked into. Is there a good reason that the industry uses kWh for battery capacity?
The factors that I can think of are:
1) kWh is what most of us see on our electricity bill, so people have some kind of reference for cost to charge.
2) You don't have to use high school physics to estimate the time it takes to charge a battery measured in kWh using a charger providing power in kW.
Neither of those is convincing to me. I imagine that mostly nerds would even bother to try and calculate anything. The rest would just ask or look at a spec sheet for basics like how long it takes to charge or how much it costs.
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I like number 4 for the USA.
That is, multiply the KWH of the battery by ten.
That gives the approximate range of mixed but easy riding.
For an example, my 6.5 KWH battery is good for around 65 miles.
My 16.3 KWH bike is good for around 163 miles.
-Don- Payson, AZ (RV trip with my Zero DS ZF 6.5)
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This how the world looks like with a metric system ;-)
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I use kWh (and "1 hour") to tell RV campground owners how much energy I'll draw, so they can very quickly decide to charge me $2 or $3 instead of the knee-jerk $10 they charge for cars.
Your reasons #1 and 2 are actually the most important reason not to use MJ, and I cannot figure out why they're not convincing to you. For as long as charging through the AC grid is a bottleneck, kWh matters when we talk to each other.
Also, the initials "MJ" are distracting.
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That is all the difference between physics and daily life. It would be logical to have an electric energy bill in MJ. It's already somehow logic that the natural gas bill (for those who are connected to a gas grid) is expressed in kWh and not in cubic meters (or feet3 or inches3 or USgallons or imperial pints or whatsoever), despite the gas counter really measuring a volume.
The general public likes not to be bothered by anything but their ordinary knowledge.
Why does a "motor" have to be electric, whereas an "engine" is considered as internal combustion (or external in older days of marine and railway)?
Why does a power in kW mean "it's electric", whereas a power expressed in "hp" means "its on fuel"? Why not on living horses...
Mankind is a troublesome species.
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I use kWh (and "1 hour") to tell RV campground owners how much energy I'll draw, so they can very quickly decide to charge me $2 or $3 instead of the knee-jerk $10 they charge for cars.
Your reasons #1 and 2 are actually the most important reason not to use MJ, and I cannot figure out why they're not convincing to you. For as long as charging through the AC grid is a bottleneck, kWh matters when we talk to each other.
Also, the initials "MJ" are distracting.
Look at the specs on Zero's website. It's got a "typical cost to recharge" listed. I think that most people will look at that rather than look at the kWh and multiply by the cost per kWh on their bill. Same deal with time to recharge. It's listed in the specifications. If you tell the RV campground manager that it will cost less than $2 to recharge and you'll be hooked up for 3 hours, I sincerely doubt they're going to check your math.
I was just curious if there was anything else I was missing, not expecting anything to change.
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When we pay for natural gas in Wisconsin we are charged by BTUs. Energy out put is heat. Let’s switch to BTUs.
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I use kWh (and "1 hour") to tell RV campground owners how much energy I'll draw, so they can very quickly decide to charge me $2 or $3 instead of the knee-jerk $10 they charge for cars.
Your reasons #1 and 2 are actually the most important reason not to use MJ, and I cannot figure out why they're not convincing to you. For as long as charging through the AC grid is a bottleneck, kWh matters when we talk to each other.
Also, the initials "MJ" are distracting.
Look at the specs on Zero's website. It's got a "typical cost to recharge" listed. I think that most people will look at that rather than look at the kWh and multiply by the cost per kWh on their bill. Same deal with time to recharge. It's listed in the specifications. If you tell the RV campground manager that it will cost less than $2 to recharge and you'll be hooked up for 3 hours, I sincerely doubt they're going to check your math.
I was just curious if there was anything else I was missing, not expecting anything to change.
Regarding the RV campground manager: nope. If I tell them literally anything other than the kWh that I plan to draw, they shut the conversation down entirely and quote the standard fee of $10.
Campground owners have no reason to believe that I know their electricity bill rate, and they absolutely do not believe me unless they do the math themselves. I tried this multiple times before settling successfully on saying "X kWh and I'll be done in under an hour".
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That is all the difference between physics and daily life. It would be logical to have an electric energy bill in MJ. It's already somehow logic that the natural gas bill (for those who are connected to a gas grid) is expressed in kWh and not in cubic meters (or feet3 or inches3 or USgallons or imperial pints or whatsoever), despite the gas counter really measuring a volume.
The general public likes not to be bothered by anything but their ordinary knowledge.
Why does a "motor" have to be electric, whereas an "engine" is considered as internal combustion (or external in older days of marine and railway)?
Why does a power in kW mean "it's electric", whereas a power expressed in "hp" means "its on fuel"? Why not on living horses...
Mankind is a troublesome species.
I receive my gas, used for home and water heating, cooking and clothes drying, from Pacific, Graft and Explosion. :o Their gas bill is measured in "therms". ???
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I use kWh (and "1 hour") to tell RV campground owners how much energy I'll draw, so they can very quickly decide to charge me $2 or $3 instead of the knee-jerk $10 they charge for cars.
Your reasons #1 and 2 are actually the most important reason not to use MJ, and I cannot figure out why they're not convincing to you. For as long as charging through the AC grid is a bottleneck, kWh matters when we talk to each other.
Also, the initials "MJ" are distracting.
Look at the specs on Zero's website. It's got a "typical cost to recharge" listed. I think that most people will look at that rather than look at the kWh and multiply by the cost per kWh on their bill. Same deal with time to recharge. It's listed in the specifications. If you tell the RV campground manager that it will cost less than $2 to recharge and you'll be hooked up for 3 hours, I sincerely doubt they're going to check your math.
I was just curious if there was anything else I was missing, not expecting anything to change.
Regarding the RV campground manager: nope. If I tell them literally anything other than the kWh that I plan to draw, they shut the conversation down entirely and quote the standard fee of $10.
Campground owners have no reason to believe that I know their electricity bill rate, and they absolutely do not believe me unless they do the math themselves. I tried this multiple times before settling successfully on saying "X kWh and I'll be done in under an hour".
Go
Obviously it's not a conversation I've ever tried. Thanks for sharing your experience.
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I use kWh (and "1 hour") to tell RV campground owners how much energy I'll draw, so they can very quickly decide to charge me $2 or $3 instead of the knee-jerk $10 they charge for cars.
Your reasons #1 and 2 are actually the most important reason not to use MJ, and I cannot figure out why they're not convincing to you. For as long as charging through the AC grid is a bottleneck, kWh matters when we talk to each other.
Also, the initials "MJ" are distracting.
In these RV camps, are you only charging but not staying overnight?
I just got back yesterday from an RV trip to Payson, AZ. I charged my Zero DS 6.5 there several times at the RV park that I stayed a week in. They were never even told I was charging anything. I often recharge at RV parks that I stay in.
I carry the Zero on an addabike ramp. (http://www.addabike.com/)
These are great with electric motorcycles as I let them power themselves up the ramp. Not so easy with ICE bikes
But when I was in Benson, AZ at an RV park, I rode the bike the 22 miles to Tombstone. The RV park in Tombstone let me charge for free and I was NOT even staying there.
I am just wondering what the norm is for this stuff.
-Don- Reno, NV
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I use kWh (and "1 hour") to tell RV campground owners how much energy I'll draw, so they can very quickly decide to charge me $2 or $3 instead of the knee-jerk $10 they charge for cars.
Your reasons #1 and 2 are actually the most important reason not to use MJ, and I cannot figure out why they're not convincing to you. For as long as charging through the AC grid is a bottleneck, kWh matters when we talk to each other.
Also, the initials "MJ" are distracting.
In these RV camps, are you only charging but not staying overnight?
I just got back yesterday from an RV trip to Payson, AZ. I charged my Zero DS 6.5 there several times at the RV park that I stayed a week in. They were never even told I was charging anything. I often recharge at RV parks that I stay in.
I carry the Zero on an addabike ramp. (http://www.addabike.com/)
These are great with electric motorcycles as I let them power themselves up the ramp. Not so easy with ICE bikes
But when I was in Benson, AZ at an RV park, I rode the bike the 22 miles to Tombstone. The RV park in Tombstone let me charge for free and I was NOT even staying there.
I am just wondering what the norm is for this stuff.
-Don- Reno, NV
Yes, I’m charging for 45 minutes to an hour, as a quick stop as I travel on my DSR with Power Tank.
Overnight camping deserves overnight rates.
But without a rhetorical framing, they want to charge me $10. I wouldn’t mind but that’s $10 every 100 miles or two hours for my journey, plus yes we’re talking about 15 kWh of electricity and a very short parking stay.
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Blame James Watt, its all his fault.
https://www.history.co.uk/biographies/james-watt (https://www.history.co.uk/biographies/james-watt)