Named after Scottish inventor and all-round brainiac James Watt, the ‘Watt’ is an internationally recognised unit of energy.
When Mr Watt was tinkering with steam within the mid-1700s he wouldn’t have dreamt that his surname would grow to be the usual score for all electrical units round 200 years later. However right here we’re within the age of electrical energy, and every little thing from the common-or-garden toaster to the newest electrical bike has a watt (or W) score.
Though this might sound a bit like a faculty physics lesson, understanding the Watt vis-à-vis electrical bikes is a good suggestion earlier than shopping for an electrical bike. This information goals to assist perceive what the Watt score refers to in the case of an electrical bike earlier than discussing the varied ranges and their benefits and drawbacks.
What’s E-Bike Wattage?
E-bike wattage is the ability output of the onboard motor. The score is the voltage (V) equipped by the battery multiplied by the utmost present (Amps of A) flowing from the battery to the motor. An instance: a 36V battery and a 15A controller equates to an e-bike motor with a 540W output.
It’s value wanting on the superb print to find how producers have calculated their motor output. Not everybody makes use of the identical methodology to calculate their bike’s score. Most use what’s referred to as the utmost steady output for the motor – an output that the motor can persistently put out with out overheating or breaking. Simply have in mind, that one man’s 250W e-bike could be one other’s 500W electrical bike.
Additionally, don’t confuse electrical bike motor wattage with e-bike battery rankings. Usually you’ll see this known as Wh or Watt-hours. Wh is the battery capability, or to be extra particular, what number of Watts it may ship to the motor per hour.
Typically, electrical bike batteries are between 300Wh and 500Wh. As battery expertise has progressed, 750Wh batteries have gotten extra widespread. Some electrical bikes even have two battery ports to maximise driving vary.

Extra Watts = Higher Electrical Bike?
The age-old query – is extra actually higher? Within the case of watts and electrical bike motors, effectively, it relies upon. E-bike motors with a excessive watt output will ship quicker acceleration, extra zip when driving up hills, and customarily higher efficiency for heavier riders.
However like a high-performance automotive isn’t normally as environment friendly as your on a regular basis runabout, it’s the identical for electrical bikes. A motor with a better watt score will drain a battery quicker, leaving the rider with much less driving vary.
How Many Watts is a Good E-Bike?
Usually talking, a 250W e-bike motor will supply greater than sufficient energy for the common bicycle owner, driving at a leisurely tempo on comparatively flat terrain. Throw in further variables, like a heavier rider, a better required velocity and a load of hills and an e-bike motor with increased watts could also be higher.
Do soak up your nation’s authorized necessities for electrical bikes earlier than buying too. Within the UK, an electrical bike or ‘electrically assisted pedal cycles’ (EAPCs) should not produce greater than 250W of most steady energy. It’s the similar within the EU. Within the USA (there are completely different guidelines in numerous states), this determine rises to 750W.
250W E-Bike
A 250W electrical bike motor is likely one of the mostly accessible. It’s going to present a satisfying push of help as you pedal alongside. They’re highly effective sufficient for many bike rides on the town and somewhat additional afield. Sometimes these motors will reduce out after reaching speeds of 15-20mph. An electrical bike motor with this score won’t present thrilling velocity on hills, nevertheless.
500W E-Bike
Transfer as much as a 500W e-bike to expertise quicker acceleration, extra energy on the hills and higher total help for heavier riders. For these seeking to put in much less effort when pedalling or these seeking to exceed 20mph, then at a minimal, a 500W e-bike motor ought to do the trick.
750W E-Bike
At 750W, issues are heating up. Driving at over 20mph is not an issue. Acceleration from a standing begin is fast and climbing up hills is easy.

1000W E-Bike
At an eye-watering 1000W, electrical bike motors are beginning to close to a boundary with electrical motorbikes. Acceleration is eye-watering and hilly rides for heavier riders aren’t any drawback. All this further energy does imply that battery juice is drained quickly, lowering your total driving vary. Returning to the plug socket continuously additionally means more cash handed over to your electrical energy firm!
Highest Wattage E-Bike
Right now some electrical bike motors are rated at over 1500W. A fast google reveals producers claiming speeds of as much as 40mph for motors of this score. At this degree, it’s exhausting to argue that these are electrical bikes anymore.
250W vs 500W vs 750W vs 1000W E-Bike
250W | 500W | 750W | 1000W | |
Prime Velocity | 15-20mph | 20-25mph | 25-30mph | 30+mph |
Acceleration | OK | Quick | Quicker | Speedy |
Hill Efficiency | Acceptable | Respectable | Quick | Easy |
Price To Cost | Most cost-effective | Low-cost | Common | Costly |
E-Bike Torque vs Watts
In any case this discuss (or ought to or not it’s torque?) of watts, it might be remiss of us to not talk about one other score generally quoted by e-bike motor producers. Torque is a measurement of the pressure an e-bike motor applies to the rear (in some instances entrance) wheel. The next torque determine is vital for offering ahead momentum on steep terrain or when driving with heavy hundreds.
Bosch’s Efficiency Line CX motor, the German model’s top-end motor can pump out 85Nm of torque. It’s entry-level motor, Lively Line has a most of 40Nm. Efficiency Line CX is most frequently seen on electrical mountain bikes the place acceleration on very steep, free terrain is important. In the meantime, Lively Line is a motor normally reserved for metropolis e-bikes the place acceleration is much less vital.
You’ll additionally see the phrase torque in relation to a torque sensor on electrical bikes. Basically this can be a system which understands how a lot energy a rider is making use of on the pedals earlier than rationing the ability of the e-bike motor accordingly. The purpose is to ship a sense like driving a standard bike.
Greatest Wattage for an Electrical Bike
When all is claimed and accomplished one of the best wattage for an electrical bike is a private alternative. Some riders would by no means take into account something aside from the utmost Watt score, while others can be more than pleased with a 250W motor.
For skilled cyclists, a 250W motor will ship greater than sufficient oomph. For newer cyclists searching for instantaneous acceleration and fast hill efficiency, a higher-wattage motor could be a greater possibility. In the end there’s no substitute for giving electrical bikes a take a look at trip earlier than you spend your hard-earned money!