Of E-bikes and range and efficiency
So I decided to run a bit of a test for range. You see, the e-bike has a simple ‘5-bar’ battery meter, not really letting you know how much farther you could go before you are doing all the work. Unlike a car, the downside of running out of juice is not as terrible, you just have to handle all the hills yourself. Also, unlike a car, the amount of work the battery/motor puts in is not 100%, and is variable. But, despite all that, I still want to know how often I have to charge / do I have the range to go there and back without having to charge or do all the work.
The setting I have available ‘Pedal Assist’ is a level from 0…9. When its on ‘0’ the electronics are all sleeping. As you step this up from 1…9, as you pedal, the motor puts in some work to match. In practise I’ve found that higher than level 1 is just not needed unless you are in a real hurry and a bit lazy. So all my riding is on ‘1’.
So for the test. My round-trip commute is 6k, so 30k/week. I started the week off with a 20k ride in ~14degree weather, followed by the weekly commute and associated errands, followed by a ~20k ride in ~6degree weather. This lead to 73.5km according to the trip odometer. I started this out ‘full’ (5 bars) and ended it on 2-bars (so ~40% if I believe the meter). This implies that I could go probably ~100km before running fairly low on battery.
The battery is 48V @ 16AH, or ~800WH. Now lets compare. Our car (Chevy Bolt) is 60kWH, and has a maximum range of about 500km in perfect conditions. So I have 1.3% the capacity, and 1/5 the range (its a much much lighter vehicle and of course no AC/heat/… so its not a fair test). In other words, the car is 6.4% the efficiency of the bike if we look at it from solely a ‘moving 1 person from A to B’ standpoint.
Lets compare against another electric. If we look at a Tesla model X P100D, this vehicle has 100kWH for 465km range, or about 3.6% the efficiency (again on the sole metric of moving 1 person from A to B).
So despite my ‘fat’ tires having lots of rolling resistance, it seems an e-bike is pretty efficient (mainly due to power/weight ratio) compared to a car.