In terms of range how much different would it be comparing riding at max speed and casual speed?

[Tony Whereisone]

Usually my wheel the 16x would last me for a whole day without any concern. 

This morning though I decided that I was going to take a trip to the countryside of the town. 

For some reason I was reaching the max speed really often but it doesn't even feel like I was going that fast at all. 

It just keeps happening! 

Within 2 hours of riding I checked my phone, I've ridden for about 50km already, and then I checked the battery. 📲

I was kinda shock as the battery said my wheel only has 40% battery left. 

I ride a little bit more and within half an hour the battery got as low as 25% 

at this point I wasn't so sure because this time I didn't push it that hard at all. 

Finally I ended my trip within 3 hours of riding. Hell it was a short trip. 

For real though It doesn't even feel like I was going that fast at all. I thought I was going at 30 but the wheel said I was at 47 already. 

And the battery, it drops way too quick , quicker than any other day that I ride. 

What's happening here? Could it be any problem with the wheel or am I just getting use to the speed?

Should I get it to check? 

And If incase I was getting use to the speed then in terms of range how much different do you find comparing riding at max speed and casual speed? 

[Ádám Szitás]

lol, I think we all got to this realization at some point.

The difference in range can be huge. You could go for 120kms+ with the 16x that lasts the whole day, if you are taking it slow. Or you can deplete it in less than 2 hours if you go on full speed all the time and only get ~50kms of range.

[bracky72]

Wind resistance makes a huge difference in range. 

[WI_Hedgehog]

In the city things are close to your body and you are going "fast" quite easily (it is a relative perception). In the country there is not much around and you can go much faster even though it seems like you are going slow. (You will notice how fast you are going if you fall.)

When going fast the electromagnets in the motor have to work much harder to change the magnetic field very quickly, and the fixed magnets pass by fast so there is not much reward for their effort. Electromagnets are inductors, so they naturally want to maintain state; changing state quickly requires a lot of effort.

When going slow the electromagnets have time to change field without as much effort, and the fixed magnets are exposed to that magnetic field for much more time, so much less energy is needed to maintain slower speeds.

Edited April 13, 2021 by WI_Hedgehog

[RockyTop]

All of the above is true. Also - If I push the wheel hard enough in a short time the batteries will sag. I can get the S18 batteries to go from 100% to 50% in a half hour. If I let the wheel sit for half an hour the batteries will settle back at about 75%. 

[.....]

I think it happens to most of us. We go faster, our legs get stronger, we deplete batteries quickly. I was also shocked at how easily I can chomp the battery on my 18L nowadays. Heck, my little butt can seasily sag the sherm down to 50%  in 30-45mins. Tis the nature of the beast. I foresee you needing to go WAY bigger than you had assumed, to keep up with your developement.

Edited April 13, 2021 by ShanesPlanet

[WI_Hedgehog]

^^^ That man will take every opportunity to talk about his saggy butt....

--

Why don't people in trailer parks invest in the stock market?

Because their money is tied up in bonds.

 

[Mantraguy]

I really like @WI_Hedgehog's answer. Another aspect is that wind resistance (which is most of the effort our wheels are fighting against) increases as a square to a double in speed. In other words, double your speed and you have four times the air resistance. Triple your speed and air resistance increases by a factor of nine! When I'm going for a long ride, I take it super easy up the hills, hold a consistent, relatively easy pace, and don't fight the wind too much. It can be easy to get some energy back while descending, but it's easier still to use lots of energy downhill by going fast and fighting the wind too hard. My long rides are pretty sedate; if I want to do a fast ride, I know it'll be much shorter.

[Tawpie]

Speed kills (and it applies to your battery). I ran into an article about how much power it takes to push a bicycle down the road where they did the physics and my takeaway was that if you double your speed, it takes 8x the power to maintain. Add to that the increased losses in your battery at high current drain and you'll see the voltage of the pack sag rather dramatically. Include the fact that as the battery is drained to lower voltage, it must deliver even more current to supply the same power as it did at higher voltage and things start to look pretty bleak. This is why you see speed throttling as your battery voltage gets lower—the chemistry of the pack coupled with the non-linear (cubic) relationship of speed and power can cause your pack voltage to sag so low you can cutout or damage the pack. Go slower: less power is required. Lower power demand = less current = lower internal losses in the battery cells = greater margin from putting a cell under voltage.

[Planemo]

The worst I have done is suck my 1860wh MSX down to 40% (resting voltage) in 20 miles. And thats without hills.

[meepmeepmayer]

@Hunka Hunka Burning Love got ~20km on his 1020Wh Tesla going full speed (~50kph), where at ~30kph usually that battery size is good for ~50 km. So 40% of the "slow" speed range by going 66%/20kph faster!

I used to get 60-65km on my ACM when I had the 30kph speed beeps. Upping to 35kph speed beeps and going slightly faster made it more like a 50-55km wheel.

Speed eats battery like crazy. Wind resistance grows fast with speed, and that is the problem.

[RockyTop]

3 hours ago, Tawpie said:

I ran into an article about how much power it takes to push a bicycle down the road where they did the physics and my takeaway was that if you double your speed, it takes 8x the power to maintain.

Wind resistance. Back when I was playing with recumbent  bicycles I was amazed at the speed that I could maintain and how much less effort it took to stay at higher speeds. 
 

Here is an old video of a very strange bicycle that I made. It bends in the middle. 
 

 

[Giffy]

All the above is true. Something I didn't hear anyone say though is that the more comfortable you get at riding, the faster you'll just naturally go I think.