Which components (except frame or bike) are at least needed to build an e-bike?
How much power can I get out of my system? The rough answer is volts x amps = watts (V x A = W)
An example: I have a battery with a voltage of 72 volts and a controller set to 50 amps, then I get a maximum of 3,600 Watts.
1,000 Watts or 1 kW is 1.36 hp. In total nearly 5 hp of input. Multiplied by the efficiency you get the output power.
Imagine this almost silent without local emissions and with a high fun factor. What does this mean in terms of speed? It depends on the windings (speed or torque), the rolling resistance (tires), wheel diameter, air resistance, weight, etc. You can compare the speeds in the motor specifications.
Higher voltage = more speed, more amps = more torque. The motors do not like low voltage and high amps…
We distinguish between two common types of motor:
Which motor is now right? There are the 35s, the 40s, the Crown- and the '54 series …
The bigger the motor, the more power it can deliver, and thereby develop less temperature which can go so high that the cable insulation melts and cause a short circuit. You can get a high power output for a short time, if the temperature is monitored. Therefore, all our motors are equipped with a temperature sensor, which can be read with the appropriate speedometer computer (e.g. Cycle Analyst V3). Here you can see an example of a modified Crystalyte 3540, which is loaded with 112 V and 400 A (yes, 44.8 kW).
We recommend for the 35XX series up to 2,500 W, for the 40XX series 2,800 W and 3,600 W for The Crown. For a short burst more is possible, but the temperature should not exceed 90°C. For a longer uphill climb, keep in mind the motor has less time to cool down than on a flat.
To the windings:
The controller is the interface between the battery and motor. At the same time all accessories like the brake circuit, the computer, the throttle and/or pedal sensor etc. are connected. More amps = more power. A controller at full capacity will get quite warm. Therefore, the controller should always be mounted outside and it is recommended to buy one size larger. More FETs generates less heat. There are also different types of FET, common are 3077, 4110 or 4115 (higher is better for more voltage).
For how long will a battery last? Let us continue with 72 volts and a capacity of 15 ampere hours (Ah). If we multiply these two values I get the available energy in watt-hours (Wh). The result is 1,080Wh or almost 1.1kWh.
That means I can use 1,080 watts for one hour. It doesn't sound much – but it is more than you think. In the acceleration at full throttle the consumption is high, but when reached the top speed goes back considerably.
For this purpose, we take an example on a sophisticated car with electric drive: The Tesla Model S. The motor has a maximum output of 310 kW and a battery of 85 kWh and the range is given as 502 km ...
There are many different kinds of battery with different properties:
A cheap BMS can destroy the whole battery pack, that’s why is also called BatteryMurderSystem! We advise to pay attention to widespread counterfeiting!
How fast can a battery be charged? It depends on the charging C-rate and the charger. If the battery has a capacity of 15 Ah and the charger a power of 5 A, then the battery in three hours is full. If the charger has 15 A, the battery is full in one hour but consider an efficiency of 90% in that scenario.
What is the C-rate? This value indicates how high a battery can be discharged or charged. We distinguish between maximum (peak) and continuous. The C-value is multiplied by the battery’s capacity: C x Ah = Ampere discharge or charge.
For example, 2C on 15Ah = 30A or 10C on 8Ah x = 80A or 1.5C on 12Ah = 18A
As you can see, a cell with a low C-rate can be compensated by a larger battery. Watch out! The manufacturers exaggerate sometimes with the values, look over the internet and forums to get the proper information.
Please always wear a helmet! If your bike exceeds the allowed power of law in your country, it may only be used on private land.
Should you choose to order parts from the USA, Canada, China, etc., then do not forget to add import tax and duty (total about 25%). People from customs are not sleeping and the allowances are relatively low (Germany: 26,30 Euro, Austria: 22,00 Euro). Normally, the courier charges another 10 euros for the processing and handling. At first glance the price may seem low, but in the end it can cost more than buying locally. For a price comparison, you can change the currency above in the right corner. Also consider returns in case of defects.
For more information look at this forum: www.endless-sphere.com
they have a beginners info as well
All information is provided without guarantee.