- Range is pack energy divided by how much energy you use per mile. Both halves are variable.
- Pack energy in watt hours is voltage times amp hours. That number, not the amp hours alone, is what to compare between bikes.
- Only about 80 to 90% of a pack's rated energy is usable in practice.
- Speed is the biggest single factor. Drag climbs with the square of speed, so the last few mph are brutally expensive.
- Cold weather range comes back when it warms up. That is physics, not a damaged pack.
Nobody gets the advertised range. That is not always dishonesty, though sometimes it is. It is that the number was produced under conditions designed to make it large: a light rider, flat ground, low constant speed, warm weather, and a brand new pack. Change any one of those and the number moves.
How range is really calculated
Two numbers. Energy in the pack, and energy used per mile.
A 72V pack rated 20Ah holds about 1,440 watt hours. If you use 60 watt hours per mile on trail, that is roughly 24 miles of theoretical range, before you set aside the portion of the pack you should not be draining. Consumption is where the variation lives, and it swings enormously between a gentle commute and hard trail riding.
The range calculator
Enter your pack and pick the riding that matches yours. The result is a band, not a number, because that is honestly what range is.
Range calculator
Voltage and amp hours are printed on the pack or in the manual.
Running a pack to zero shortens its life and risks a shutdown under load. 85% is a sensible working figure.
What takes the biggest bite
| Factor | Effect | What to do about it |
|---|---|---|
| Speed | Largest by far. Drag rises with the square of speed | Nothing, except go slower when range matters |
| Terrain and climbing | Large. Every foot of elevation is energy spent | Plan the route. Climb early while the pack is full |
| Total weight | Moderate, and worse on hills | Leave what you do not need at home |
| Cold | Moderate and temporary | Nothing. It returns when it warms up |
| Tire pressure | Small to moderate | Keep them at the right pressure |
| Throttle habit | Moderate, and entirely yours | Smooth inputs use less than stab and coast |
| Pack age | Slow, permanent | Good charge habits slow it. See the battery guide |
Why the spec sheet says otherwise
Advertised range figures are usually produced in eco mode, at a low constant speed, on flat ground, with a light rider, in mild weather, on a new pack. Every one of those choices is defensible on its own and the combination produces a number nobody will see in normal riding.
It is not always dishonest. There is no shared standard for range testing on these bikes, so every brand picks its own conditions, and the brands that pick the gentlest conditions get the biggest number to print. Compare watt hours between bikes instead. That figure is much harder to flatter.
- Multiply voltage by amp hours on each. Compare the watt hours, not the advertised miles.
- Check the weight. A heavier bike spends more of that energy moving itself.
- Ignore any range claim that does not say the speed and the rider weight it was measured at.
Getting more of it
Steady throttle beats stab and coast. This is free and it is worth more than most riders expect.
Backing off a few mph returns more range than any single part you can buy, because drag scales with speed squared.
Two minutes, and underinflated tires quietly cost range on every ride.
Weight costs most on climbs. A lighter pack on your back is range in the battery.
On a commute, a charger at work turns range anxiety into a non-issue and lets you keep the pack in the gentle middle of its charge window.
Note miles and charge used across a few rides. Your own Wh per mile beats every estimate on the internet.
Gear in this guide
Inline Voltage Meter, Pack Side
