What’s your real-world e-bike range?

[Chazmo]

Hi guys! I was thinking about how subjective the “up to X miles” is, so I wonder if you would like to share your actual consumption and the conditions behind it, for example, motor type, voltage, your weight or cargo, terrain, temperature... I'm curious to know if there is a significant difference between what you experience in different situations vs the range that manufacturers advertise

I got pretty much what I expected when I bought my Juiced fat-tire bike a few years ago. Practical limit is 50 miles on easy trails and road with hills.

I suppose what you get as an estimate from the vendor will vary wildly. Good luck in the hunt.

 

[speedub.nate]

Another variable to consider: "protected reserve" to run the lights.

Well, that's my name for it.

Last night I rode home in "Trail" mode which, to the uninitiated, is Shimano's stock middle level of pedal assist (although its power output is much closer to the top than to the middle). I also took a slightly hillier route home, but still... only 400' of climbing.

Anyhow, this morning I did my usual Eco mode into work but for the final 1½ miles shifted up to Trail mode because I was running a couple of minutes behind schedule. At about the same time that I switched to Trail mode, my battery went from 2/5 bars to 1/5 (red) bars, but no problem, right?, because I've only got like one mile to go.

Nope.

With about ½ mile remaining, the motor shut off. It wasn't until I got to work that I noticed I had left my lights on. I know there's a setting in the Shimano programming having to do with reserve battery for headlight use, but what I don't know is if this protection buffer is based on the real-time status of the lights. For instance, if I had shut the lights off, would the system then give me back some of that buffer?

This bike also as Di2 shifting and needs to run the display, so there is always some battery reserve, but today was the first day of a 2x commute consisting of Trail + Eco (mostly) killing the battery.

 

[Stefan Mikes]

You are absolutely correct Nate. All good e-bikes have -- as you name it -- a protected reserve. The first reason is discharging an e-bike battery with the full current at the low charge is very dangerous to the battery, and it could not only damage it but also lead to even worse consequences. Hence, most decent e-bikes cut the assistance off around 5% battery charge level and keep anything remaining to feed the e-bike computer, lights and other electronics. How the approach to 5% is done and how the cut-off is practically implemented depends on the specific brand's approach.

• Giant e-bikes behave normally down to 20% battery level. After that, the battery charge falls off the cliff, and the motor is cut-off at 5%, keeping the e-bike computer and the lights alive
• Full power Specialized e-bikes slightly derate the motor below 20% but you can use almost the full power until 5%, when the motor is cut-off, and the reserve is kept for the lights and the system
• Lightweight Specialized SL e-bikes strongly protect the Main Battery and Range Extenders. If the RE discharges first, it is totally cut off between 10 and 5%. Below 20% of main battery, the first level of motor derating is applied: the e-bike feels weaker and slower. Below 10% battery level, it is the full motor derating, with only a fraction of the normal motor power available. Below 5%, the main battery is reported as 0%, and only the critical systems are still fed with electricity.

Even if I have ridden my Vado SL for the last 5 1/2 years (and own 4 Range Extenders), only recently I could realise what a discharged Main Battery was doing to the e-bike. As long as the Main Battery is between 10-5%, the motor will remain heavily derated even if you feed a 100% charged Range Extender! Worse: Connecting a fresh Range Extender prevents the Main Battery from further discharging, keeping the motor derated until the very end of the ride!

Now, my strategy for long SL rides is the following:

• Ride with "Discharge the Extender battery first", and discharge all available REs first, possibly never going below 20%
• With the last RE available, switch to "Discharge both batteries in parallel" and use the Main Battery and the last Range Extender
• Never allow the Main Battery discharge below 20% if you have any Range Extender still available.

The SL case is limited to a very specific Specialized e-bike model family but I think @Jeremy McCreary could find my observations interesting.

 

[speedub.nate]

This is the one I'm referring to: not the "baked in" housekeeping battery reserve that prevents the cells from being underrun or overcharged, but a user-selectable buffer that leaves a little for tasks other than driving the motor.

This is a screenshot from Shimano documentation; I need to plug in an see what level I have mine set at. 18 Wh doesn't translate into a whole heap of range, but maybe mine is set higher.

 

[Jeremy McCreary]

My 36 lb, 240W, 35 Nm power-sensing Specialized Vado SL 1 mid-drive has a 320 Wh battery. At 15-20% charge, the bike starts reducing power to the motor for a given rider power input, but I only notice it below 10% or so.

Below 3%, no power goes to the motor, but the bike's still quite rideable with the motor off. In fact, I often ride this bike in OFF by choice. No adjustment to this 3% in the app.

As a matter of policy, I try to avoid taking the battery below 10%, though nothing in the manual says so. That presumably leaves me with roughly 320 x 0.90 = 288 Wh to burn.

Depending on the vertical gain and how I ride it, pretty sure I could squeeze 50-60 mi out of that in my hilly and rolling terrain. My longest ride of 41 mi with 51 ft/mi of climbing supports that guess.

Don't recall if Specialized claimed a range for this bike.

 

[Stefan Mikes]

As a matter of policy, I try to avoid taking the battery below 10%, though nothing in the manual says so.

While the Main Battery is still full but the Range Extender is getting cut off (the e-bike motor is highly derated in this state), the motor suddenly gives its full set assistance again. You could be surprised by the difference! It feels like the e-bike's rebirth!

I write this because I made a gross battery/RE mismanagement on the Heights 2 ride, and asked my mates to leave me be until I could make the Main Battery display 0% (cut off) on the Wahoo. To do that, I had to disconnect RE and ride until the MB gave up.

 

[JL0256]

When people share their range, could they also mention the battery level at the end of the ride? Finishing a normal route with charge left isn’t quite the same as riding until assistance stops. That detail would make the distances easier to compare—no need to run the battery down just to get a number.

 

[speedub.nate]

...also mention the battery level...

Nearly impossible with my Shimano bikes, nor with one of my Bosch bikes with the older, monochromatic Purion display. They show me 1-5 bars, that's it, no percent. And as mentioned in my prior post, the Shimano gave me one flipping mile on flat ground on the last bar before calling it quits. Definitely not representative of 20% of my working range. Nearly as useless as "remaining range."

 

[Stefan Mikes]

When people share their range, could they also mention the battery level at the end of the ride? Finishing a normal route with charge left isn’t quite the same as riding until assistance stops. That detail would make the distances easier to compare—no need to run the battery down just to get a number.

It is impossible to determine a real range without running the battery down to the lowest possible level. There are several reason for that:

• Non-linear battery consumption with the battery partly discharged
• Changing riding conditions: any hills remaining? Wind direction and speed?

One of the former pillars of EBR Forums, one David Berry of Brisbane Australia was on his 100+ km rides on every single day. One day, he set off for another long ride and was pleased by a long range reported on his e-bike display. After he decided to go back, he was hit by headwind. He instantly realised he wouldn't reach home on the battery! Fortunately for him, his ride happened to be in the civilised part of Australia, so he was able to take a train home...