ElectricMotorcycleForum.com
Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: KuRi on July 02, 2020, 02:59:51 PM
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Hi!
I want to do a trip to the beach this weekend, and there is 90km of distance. I can charge the bike at the destination, but not along the way. The problem is that the return to home is uphill during all the 90km. The specs says that I should be able to travel 126km at 113 km/h. I have checked this on a flat road and it is more or less accurate, but what about uphill???
It is too risky? xD
Thanks!
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I can’t speak as a DSR owner but as an SRF owner I’d be ok with that trip so long as I started the return trip on 100% charge. I’d have <20% neutral regen assuming the road is mostly uninterrupted (not start/stop) as coasting is more efficient and a high brake regen to claw back what I could when I need to slow down. I’d keep torque (acceleration) to a minimum or just be gentle with the throttle. I’d also keep top speed under 55mph if possible. Elevation will be key though, if it’s a lot of climbing (>1km) without the downhill then it could be a risk, but my SRF would suffer more than your DSR I’d suspect as the SRF is heavier.
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Yes, it is a constant climbing to the destination, that's my main concern :D
Thanks!
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Don't forget that you can almost always squeeze out a little more range by going slower. You can't eliminate the loss of charge due to elevation gain, but you can almost always reduce the loss due to wind resistance. If you're willing and able to reduce your speed without risk of being run over by faster-moving traffic, you're almost always capable of reducing your drag and increasing the range.
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Hi!
I want to do a trip to the beach this weekend, and there is 90km of distance. I can charge the bike at the destination, but not along the way. The problem is that the return to home is uphill during all the 90km. The specs says that I should be able to travel 126km at 113 km/h. I have checked this on a flat road and it is more or less accurate, but what about uphill???
It is too risky? xD
Thanks!
You probably get less than half the range going uphill (depends on how steep, of course) but you get around double the range by going half the speed.
So go as slow as possible on the way back.
-Don- Reno, NV
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With my previous bike (BMW F800GS) I was able to go down and back with a single tank, and the range was about 220km on a single tank, but I guess electric bikes are completely different :)
I am not sure if I will take the risk but if I do, I will let you know the results xD
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motorcycles are light, so the total amount of energy to move the bike up the hill is typically insignificant. If the destination is 1000m (3300ft) higher than the starting point, that is 300*9.8*1000 = 2.94MJ of energy (about 0.8kWh) assuming total bike+rider weight is 300kg (660lbs) Assuming 85% efficiency of converting battery energy to potential gravitational energy, that would use about 0.94kWh of battery to lift the bike up that evlevation change, so it takes such a large hill to become significant.
Assuming going down the hill to the beach you "recover" potential energy at 100% efficiency, the difference of battery usage to get down the hill vs going up the hill would be about 1.75kWh. So if you make it to the bottom of the hill with 1.75kWh left in your battery, and you charge up to full while you are there, you should be able to make it back traveling at the same speed. If you have less than 1.75kWh when you get to the bottom of the hill, you will want to travel up the hill more slowly than you came down, to spend less energy moving the air around you.
Again, that assumes a 1km (3300 foot elevation change). Also note this calculation assumes the elevation at the start and the end of the trip, any increase / decrease in elevation between those two points roughly balances out and doesn't influence energy consumed that much (as long as you have enough energy to make it to the top of the highest point between the start and end).
Another thing to consider is prevailing winds and air temperature, which will both affect aerodynamics. I believe typically, winds blow off the ocean, so you may have a prevailing tail wind going up the hill, since the bottom of the hill is a beach. A 7-10kph wind can have significant impact on your range, especially if it is against you going one way, and with you going the other. Also air temperature has a significant impact on range, a study I read about bicycle racing and the effect of temperature on aerodynamics suggest that for every 10C temperature increase, the aerodynamic drag decreases by 3%. And depending on your speed, the most significant influence is your riding position. If you need to extend your range by 10-15% you can simply tuck to reduce your total cross section area, the faster you go the more tucking will affect your range.
If you want an adventure, go for it, do some math to prepare yourself to adjust your riding style if you find it necessary, and have a backup plan should things not work out the way you hoped. Without adventure life is boring.
-ryan
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Yeah, I can confirm about half range going up hill. Going up to skyline (about a climb of a little more than 2000' in about five miles) I use about 25% of my SoC while I use about half that or less the other way.
Of course it depends how steep. And how cold. Yesterday my bike was acting like it was freezing out and was just chewing through charge and used about 50% more SoC than the day before to do the same thing.
-Crissa
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Very nice explanation Biff, although it is contradicting what others are saying about half range going up hill. However it is similar to what I was thinking.
The total height diff is about 700m, and there are about 10km of flat roads (now that I recap).
Thanks all!
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It depends on the grade of the hill. It's going to require the same amount of extra energy to climb 700m whether it's over 10 miles or 100 miles. Using Biff's math it would require an extra 0.56kW/h, so if it's over a distance that would require that amount of energy on flat ground you've just doubled your energy consumption, if the distance would instead require 0.056kW/h then you've only added 10% onto your consumption.
Going with an approximate energy consumption of 75w/h per mile the climb would have to be over a distance of about 7.5 miles to double the consumption. Over your 90km distance it's an increase of 13.6%.
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You can figure out the range yourself by looking at the KWH consumption on the Zero app.
I was surprised how much energy it takes to go DOWNHILL at 75 MPH. I was just checking that on my Energica. I was drawing 7KW so the bike would not slow down at all, at 75 MPH down a fairly steep hill on the freeway. Then I had to climb up the next hill, about the same grade. Then I was drawing 24 KW.
Let's say you have a ten KWH usable capacity battery. If you see the draw at 20 KW, you know you can ride at that speed for 30 minutes. If you draw only 5 KWH, then you can keep that up for two hours.
The math you can do in your head. You can see what speed you need to go a distance and such by using simple math, after seeing the KWs being drawn. But what ever that speed is, try to keep it steady, such as a cruise control would do.
I find the KW being used to be the most handy info. IMO, that should be in large digits on every EV screen, but usually it's small.
-Don- Cold Springs Valley, NV
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Several times I've done a 90 km loop on my FX 6.5 with over 1000 m elevation gain. I found that I get home with 5% remaining if I had it in sport mode, or 12-15% remaining if I had it in eco mode. I believe you'll be able to do this conservatively, starting with 100% at the bottom, if you're sparing on the throttle and keep a speed of around 60 kph.
700 m is not much of an altitude difference. However, are you sure it's strictly uphill? If there's any downhill then you'll have more cumulative uphill. If 10 km is flat then you're taking about an average grade of 0.875% for the rest, which is very mild compared to the area around the Zero factory. Note that any time you brake or regen kicks in, it means you're consuming more energy than you otherwise would have.
Welcome to range anxiety (I admit that when I was experimenting, I knew that if I ran out I'd be close to home and could pick up the bike in my truck.) The nice thing is that once you've done this trip once, you'll know how much power you have left over, for next time.
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Hi! Yes, it is a constant uphill for at least 60km-70km. It is a highway, so minimum legal speed is 60kph but going at that speed will get me a lot of angry car drivers using their horns against me xD
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The specs says that I should be able to travel 126km at 113 km/h
You know, after noting again that the 126 km spec is for full highway speed, I think the elevation isn't a big deal and you'll be able to do the 90 km easily at say 100 kph. I say do it! :)
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Yeah, I do a 60km route over a pass 795m high with a median speed of 60kph (maximum 80kph, min 40 kph, mostly in the middle) and I use 50-60% of my five-year-old 8.5kW pack, even in winter.
Take that what you will.
-Crissa
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Biff is entirely right.
See also here: https://electricmotorcycleforum.com/boards/index.php?topic=7325 where I gave a spreadsheet to make your own calculations. But I did not take into account the efficiency of the conversion from electric energy to mechanical energy estimated to 85%. So you have to divide the kWh given in the spreadsheet by 0.85 to get more accurate predictions.
I join an updated spreadsheet with this correction.
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Nice, Thanks! I was sure there was a place to charge my bike at the destination but I phoned there and there is not... Without been able to charge there and start my trip back at 100% energy my adventure is paused until I find another solution :)
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Nice, Thanks! I was sure there was a place to charge my bike at the destination but I phoned there and there is not... Without been able to charge there and start my trip back at 100% energy my adventure is paused until I find another solution :)
Always check Plugshare (https://www.plugshare.com/) before using a charger. What location was that?
Plugshare has worldwide coverage and explains what you will need to know at each charge station.
-Don- Auburn, CA
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I am from Spain, here we have https://www.electromaps.com/ for that purpose, and although it says there is one charge point where I was planning to go I phoned them and they confirmed me that was an error :(
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There are some plugs on plugshare which are not public, very frustrating.
They really need tags like 'gated' 'pay garage' and 'private'
There are some I know which you have to walk up and ask, and some you get yelled at for walking up and asking unless you're already a customer for their other services.
-Crissa
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There are some plugs on plugshare which are not public, very frustrating.
They really need tags like 'gated' 'pay garage' and 'private'
There are some I know which you have to walk up and ask, and some you get yelled at for walking up and asking unless you're already a customer for their other services.
-Crissa
That information is usually on Plugshare. That is why I say to use it. And if you notice anything that needs to be said there, then YOU be sure to put that info. on PlugShare, just as I do. Have you posted anything on Plugshare yet? I check in at everyone I use as well as the ones I cannot use for ANY reason. I normally upload photos as well. You will see my Energica and my comments at almost every charge station I have used in this area of CA or near Reno. Such as here at KingVale, CA (https://www.plugshare.com/location/123513) and here at Grass Valley, CA (https://www.plugshare.com/location/182275).
Lately, I have been taking Hwy 20 between here and Reno. Much less boring than I-80.
-Don- Auburn, CA
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I am from Spain, here we have https://www.electromaps.com/ for that purpose, and although it says there is one charge point where I was planning to go I phoned them and they confirmed me that was an error :(
Can people "check in" on Electromaps and leave info? That is the most important part of PlugShare as if a station is down or cannot be used for any reason, somebody usually reports it.
Here is an example of a charge station that I could NOT use (https://www.plugshare.com/location/152887), I knew it before I got there, but I checked it out for myself anyway. Notice five negative check-ins. That should convince anybody to not try to charge there.
-Don- Auburn, CA
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Descriptions are not tags, tho, Don.
-Crissa
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Descriptions are not tags, tho, Don.-Crissa
What do you mean? You say what you want to say on Plugshare when you check in. Have you ever checked-in on Plugshare?
You should be able to see what I said for the Grass Valley DMV charge station, that the "Gate is closed on Saturdays". If you didn't see that, you're doing something wrong.
The rest of the check-ins from the others all said they could not use that station. Seems nobody has ever successfully used it, by reading all the check-ins.
So I knew I could NOT use it before I rode up there just to see it for myself.
-Don- Auburn, CA
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I think he's trying to say that you can't exclude from a search the stations that can't actually be used, instead you have to go through and read the reviews for each one. I can understand why it's that way, many of the issues aren't permanent or are specific and unique things that can't be boiled down to a simple tag or don't apply to everyone.
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Yeah, but many boil down to 'hours' 'parking charges' 'ask first' and 'residents only'
-Crissa
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Yeah, but many boil down to 'hours' 'parking charges' 'ask first' and 'residents only'
Yep, and that is exactly what you need to check on every trip at every location you want to charge at before you leave home!
For an example, there is a charger in Elk Grove (https://www.plugshare.com/location/13814)that anybody can use. That is anybody ONLY If you know the nine digits to enter on the keypad to start the charger. I got the code on Plugshare before I left for Elk Grove on my Zero SR.
"Code "12341234#" works for a free charge."
Just looking at where the charge stations are located is often just a waste of your time. I would not even bother to look at the locations without reading about every one that I wish to use. And even for the next trip to the same areas. Things change.
For an example, a charger was out of service the other day in Truckee, CA because they had to repave around it. But only out of service for one day. The info. for that one day was on PlugShare. Before, during and after it was again usable was all reported.
And if you find something inaccurate then you should post it on Plugshare. So far, I have only got what I expected at every charge station, not counting a temporary problem with getting one DC fast charge station to start! And that problem was reported by me and even mentioned in this forum. But I did get my charge even there. And that was when I met BigPappa from this forum who also had problems there. We were both trying to charge our Energicas. After around 20 minutes we somehow got it to start.
The mistake we made was to follow the instructions on the DC Fast Charger. The mistake was that the charger's firmware was recently updated, but not the instructions. The instructions said to "plug in first". But it would only work if we start the charger first and then plug in, as I found out later. And so I posted that on Plugshare so others won't have the same problem. At first, I was thinking it wasn't compatible with the bike. Later, I found out about the charger FW change without anybody updating the instructions.
Another way we could have charged (as somebody explained in this forum) was to use the app to turn on the charger. But we didn't know that.
BTW, I would not try to charge there now. See here for why. (https://www.plugshare.com/location/163259)
-Don- Auburn, CA
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Yes, and when I go about San Jose, about half the chargers aren't public.
So yes, I have to read them.
But that's a heck of alot of wasted time searching for a working charger when I could just filter out all of the ones that are in apartment buildings and hotels that are not available.
-Crissa
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Yes, and when I go about San Jose, about half the chargers aren't public.
So yes, I have to read them.
But that's a heck of alot of wasted time searching for a working charger when I could just filter out all of the ones that are in apartment buildings and hotels that are not available.
-Crissa
It never takes me more than a few minutes. We normally don't go all that far on electrics and only need to find a few charge stations in most cases.
BTW, on my electric bikes, each has a Garmin GPS. The Garmin 395LM that does everything, such as play MP3 music via Blutooth , and a built in TPMS and more. In these GPSes, I put in separate directories for slow and fast charging on my Energica, but only AC charge stations for my Zeros. I only add the ones within range that are likely to work okay for me. But I normally check Plugshare to make sure the most important ones are up and running. For some other areas, I can take my chances as there are many other chargers in those areas.
-Don- Auburn, CA
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I wanted to check out the one in Elk Grove. Unfortunately, Maps says it is 555 miles from my house and I have to work in the morning. ;D
I try to check in when using Plug Share. Few others seem to here in Vegas though. I have ridden my SR to and From Los Angeles a
few times. At the time, there was nothing between Victorville and Primm. Had to resort to finding unused 110 plugs behind soda machines
at rest areas. A Little better now, but since Zero doesn't have LIII available, not a lot of help.
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I wanted to check out the one in Elk Grove. Unfortunately, Maps says it is 555 miles from my house and I have to work in the morning. ;D
I try to check in when using Plug Share. Few others seem to here in Vegas though. I have ridden my SR to and From Los Angeles a
few times. At the time, there was nothing between Victorville and Primm. Had to resort to finding unused 110 plugs behind soda machines
at rest areas. A Little better now, but since Zero doesn't have LIII available, not a lot of help.
I charge my 2017 SR at 6.4 KW on the road, as high as 8.4 KW while at home. 240 VAC, of course. With extra chargers. With Level Two, I can charge my Zero a lot faster than my Energica (3.0 KW). However, the Energica at about 25KW on a CCS DC fast charge.
-Don- Auburn, CA
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The zero in app range estimator has a penalty for things like aggressive riding, cold temperatures and hills. That penalty is 10% which is quite high but still this is for both up and downwards riding, so I would take more in your situation. Here you can find some details on how I got to that penalty number https://bitbucket.org/cappelleh/zeronextgen/issues/26/android-range-estimation-tool