General design of an electric scooter
To understand how to assemble a scooter yourself, you need to understand its design. The structure consists of the following parts:
- Frame;
- Wheels;
- Electric motor;
- Controller;
- Accumulator battery;
- Brakes;
- Controls.
The principle of assembling a Li-ion battery for an electric bicycle
To assemble a Li-ion battery for an electric bicycle with your own hands, you will need:
- calculated number of lithium-ion cells, for example, the popular 18650 configuration;
- connecting wires and connectors;
- BMS control board;
- soldering iron, preferably with thermal stabilization;
- low-melting solder;
- ammeter;
- large diameter heat shrink tube;
- fire protection bags;
- a case or other suitable container for placing the resulting assembly in it - you can use a homemade or purchased box made of plastic or metal;
- Charger.
To create a battery, lithium-ion “banks” are placed in pairs in bags, observing polarity. Using a parallel connection, the required capacity is collected. Power and balancing wires are connected to the cells. Next, using a series connection of the packages, the required voltage is provided. Extension cords are used for external output of connectors. The balance wires are connected in series.
The cells are tightly compressed, packed in large-diameter heat-shrink tubing and placed in a prepared case with pre-drilled holes for the wiring to exit. By soldering, a BMS board is attached to the resulting battery. After the wires are brought out, a plug is attached at the top to recharge the battery. The openings of the box are sealed. The cable from the manufactured battery is then connected to the electrical controller, and the battery is installed in the frame triangle, on the bike rack, or in another designated location.
Frame (base)
The easiest option is to take a frame from a factory scooter. The disadvantage of this option may be the additional load on the frame. After all, the weight of additional equipment will be added to the person’s weight. The undoubted advantage of this is its relative simplicity.
The second option is manufacturing, as they say, from scratch. The advantage of this method is that the device will take into account all individual wishes and characteristics.
For making your own frame, a square pipe with a wall thickness of 2-2.5 mm is suitable. True, here you will need additional skills for designing and calculating the base, skills in working with materials and tools.
Battery replacement
A complete replacement of the battery along with the housing is necessary when the old battery is located in an inconvenient place , for example on the trunk, which has a bad effect on the weight distribution and center of gravity of the electric bike, and it is advisable to move it to a more convenient place. The best place to place the battery is in the downtube of the main frame triangle.
The second case is to replace the battery along with the case, when the case of the old battery is too small to accommodate a sufficient number of cells.
Replacing a 48V “bottle” with a residual capacity of 3.5Ah with a 48V 19.2Ah battery from 21700, 4800 mAh TSL cells
However, there are cases when the case is in a convenient place, for example behind the seat tube, and there is plenty of space for a new capacious battery - The Chinese often pack small assemblies into a large case, filling the voids with foam rubber.
In the photographs below, we see how the economical Chinese placed a 13s3p battery of 18650, 2000 mAh cells, with a total capacity of 6 Ah, into a large convenient case with internal dimensions of 115 * 85 * 290 mm. Instead, a 13s4p battery of 21700, 4000 mAh cells with a capacity of 16 Ah easily fit. And this choice was dictated solely by financial capabilities, because... physically there was enough space to accommodate a 13s5p assembly from NCR21700 (TSL) cells, with a cell capacity of 4800 mAh. That is, a battery with a capacity of 24 Ah could fit into this case - 4 times more than the standard one!
Wheels
Wheels are divided by size into micro, mini, midi and maxi. The first have a size of less than 20 cm, the second - 20 cm, the third - from 25 to 30 cm, the fourth - more than 30 cm.
Note!
- DIY induction heater ♨️ - reviews of the best manufacturing options. Varieties of homemade device designs + step-by-step master class (160 photos)
- Do-it-yourself Gauss cannon: TOP-130 photos of the best ways to create it yourself. Design features + master class for beginners
- DIY clamps - a step-by-step master class for beginners. Schemes for manufacturing different designs + 170 photos
The choice of wheels to be installed on the scooter depends on its operating conditions. If you drive on smooth roads, then micro-sized wheels are suitable. An electric scooter with them will be light and compact.
If the roads are of average quality, with small cracks and unevenness or are paved with tiles, then the mini option is better. If you plan to move on poor asphalt or dirt roads, then it is necessary to install midi or even maxi size wheels. Inflatable wheels are also suitable.
Safety precautions
An electric scooter, despite its low speed and weight, sometimes causes injuries and traffic accidents. Sidewalks are often chosen as places of movement. They are not always wide, so you should not accelerate too much. Traditionally, mothers and children walk along the sidewalks. The speed of the scooter and the curiosity of children can cause a collision.
To drive safely on sidewalks, follow the following rules:
- maximum speed - 15 km/h;
- if there are a lot of people, it is better to dismount and drive the scooter in your hands;
- when approaching children, slow down;
- equip the vehicle with a bell.
Riding along roadsides and cobblestones on a scooter with small wheels is not easy: it is difficult to maneuver. Moving along a street filled with cars is also fraught with danger: it is difficult for drivers to notice a small scooter. They often believe that a person is walking and do not expect quick maneuvers from him.
To protect yourself from accidents and injuries, follow traffic rules. Besides:
- put on a helmet and protective clothing;
- select areas with low traffic intensity;
- look carefully at the road so that the small wheel does not fall into a pothole;
- control the situation behind them.
To travel at night, scooters must be equipped with lights. It is better to install the front one higher on the steering wheel; it should illuminate the road well. A rear marker light is required. It is recommended to limit the speed of movement at night to 10 km/h.
Engine
A wheel motor can be used as a motor. It can be purchased separately or taken from a broken hoverboard. A motor from a cordless electric drill can also be used as a propulsion device. Some craftsmen use a screwdriver or a car radiator cooling engine as an engine.
Engine power is selected depending on the conditions in which you intend to drive. For children, it is better to take low-power engines. For driving at speeds up to 30 km/h, a motor with a power of up to 300 Watts is suitable.
For fast driving, you can use motors with a power of 350-400 watts. Such an engine will allow you to reach speeds of up to 40-50 km/h. It is important to consider safety issues here.
Precautionary measures
When assembling a lithium battery for an electric scooter yourself, it is important to be careful and careful:
- Do not heat, deform, puncture batteries, drop or squeeze them;
- Reverse polarity, overcharging, short circuit must be avoided;
- If the battery or charger gets too hot, stop using it;
- It is permissible to use only cells of proven quality, without signs of damage, for battery assembly.
If you do not have enough knowledge and experience, it is better to buy a ready-made battery for an electric scooter or have it assembled by experienced craftsmen. In this case, you will receive a battery of guaranteed high quality, without the risk of accidental flaws during its assembly and problems during operation, in addition, you will save your effort and time.
Read our previous article about the types of bicycle forks, their design and operating principles
Accumulator battery
The distance the scooter travels depends on the battery. There are several types of batteries: lead-acid, lithium polymer, lithium ion, lithium iron phosphate. The former are known for their use in motorcycles and cars. They are heavy and have a small number of charge-discharge cycles compared to other types.
Note!
- DIY rocking chair: TOP-120 photos of the best manufacturing options. Master class on creating a rocking chair at home
- Smokehouse from a gas cylinder - the best master class on making a homemade smokehouse with step-by-step photo diagrams for beginners
Do-it-yourself compressor: TOP-130 photo reviews of finished compressors. Step-by-step instructions + diagrams and drawings
Polymer and ionic are the most suitable in terms of weight, technical characteristics and price. For lithium-polymer batteries, the number of discharges and charges is up to 800, for lithium-ion batteries – up to 1000 cycles. Both types are lightweight and dependent on ambient temperature. In cold weather the discharge occurs faster. In addition, there is a danger of fire or explosion when overcharging.
The lithium iron phosphate battery is not afraid of mechanical damage, is resistant to low temperatures, is not afraid of overcharging and has up to 2000 charge-discharge cycles. But it is heavier and more expensive than polymer and ion batteries.
You can buy a ready-made battery pack, or you can assemble it yourself, for example, based on 18650 batteries. Which one to use depends on personal preferences and available resources.
Battery installation is done in different ways. Can be installed below in a platform called a deck. This option is preferable as it does not raise the center of gravity. But in this case, additional protection against impacts and mechanical damage is required.
Another location for installing the battery is the steering column. There, either a hanging container is made, or installation is carried out in a rack if it is made of several pipes.
Note!
- Do-it-yourself wind generator: TOP-170 photo reviews of finished devices. Detailed DIY instructions for beginners
Do-it-yourself spot welding - the best master class on making homemade spot welding with step-by-step photo diagrams of do-it-yourself work
- Do-it-yourself tennis table: TOP-150 photos of the best manufacturing ideas. Master class on creating a tennis table at home
No matter how the battery is mounted, it must be protected from moisture. Waterproofing of a self-made electric scooter is carried out using electrical tape, sealants, and the manufacture of moisture-proof covers.
We introduce an electric battery and automatic
The battery was wrapped with tape to provide better protection from moisture. It also makes sense to attach it to the deck using double-sided tape or Moment glue. Between the deck and the electric battery you need to install a gasket made of some dense material - it will be better! Our professor settled on a plastic folder for papers!
The automatic switch is the switch for the electric scooter, so without it there’s no way! In our case, it was glued to the electronic drive, but you personally can adapt this device anywhere.
Controller
The controller is, one might say, the brain of the engine. How the scooter will ride and its acceleration at the start depends on it. Selected according to engine parameters. If the motor consumes 36 V, then the controller must be 36 V.
The power is selected taking into account the reserve for the starting load and forced movement. As a rule, a reserve of 2-2.5 times the current is taken. That is, if the motor has a power of 300 Watts, then its rated current is 8.3 A (300W/36V). This means the controller must withstand up to 21A.
We are installing the controller and accelerator handle
In principle, everything is clear with the gas handle, but the controller needs to be removed from the aluminum case and sealed with tape. For the device under discussion, the owner purchased an Infineon 6 FET controller, but for its successful implementation, it was necessary to file down the textolite so that it could adequately fit in its rightful place.
There is also a budget class controller Bafang 500W. It is made in a small case that has three speeds and the possibility of recovery, and it consumes 14 A from the electronic storage device. However, its main advantage is that the product fits into our deck, albeit without a case - there is no need to finish it.
A hole is made in the side of the deck, and there are holes in the controller’s radiator through which it is possible to fix the device using this very hole.
The niche with the wires and the controller must be covered with a lid. To make the lid, sheet plastic will do; in our example, it was made from a laptop, and specifically from the lid of its matrix.
As for the throttle, in our time there are no problems with this - we purchase the most suitable modification and calmly move the equipment to its rightful place.
Control
The scooter controls consist of a power switch, gas and brake handles. It is better to make gas in the form of a hook, because it is safer. In case of an unforeseen situation, such a handle is instinctively released.
The brake handle must be equipped with a switch that will turn off the engine when pressed.
Now let's look at a few instructions on how to make an electric scooter using different engines.
Pros and cons of a homemade battery
The decision to assemble a battery for an electric bicycle yourself is completely justified if you have free time, high-quality cells, the required tools, sufficient knowledge and skills to reliably assemble the battery. Personal assembly of the battery allows you to save money and obtain a product that exactly matches the specified characteristics - any shape, any dimensions, with optimal technical characteristics.
But if knowledge and experience are not enough, it is better not to take risks and buy a ready-made Li-ion battery with the required characteristics or order its individual assembly from competent craftsmen. This solution will save time, effort and money, since the first independent assembly of a battery assembly is rarely successful.
It is easy to select a battery with standard characteristics in our catalog, and to order you can assemble a battery with non-standard parameters. Order lithium batteries from us - we offer high-quality assembled batteries with a guarantee and delivery throughout Moscow or to the regions of Russia.
Go to the bicycle batteries section
With a hoverboard wheel
It's enough to make a scooter using a broken hoverboard. Such a device will look quite aesthetically pleasing. In addition, it will have good technical characteristics.
The manufacturing scheme for an electric scooter from a hoverboard is as follows:
- Take one motor-wheel from a hoverboard;
- If we use a frame from a finished scooter, then make a fork to attach the rear wheel under the wheel from a hoverboard. If we make the frame ourselves, then we immediately take into account the fastening;
- Install the motor controller;
- Install the battery;
- Install the throttle handle and the power button.
After installing all the parts and elements, we check the functionality and use it for your pleasure.
Let's remember our skills
Finally, after much painful thought, you came to the conclusion that purchasing an expensive item is not for you! What is the further course of events in this case? First, check your skills: you must be able to use a soldering iron well and operate a screwdriver, that is, make neat holes in metal using this device.
So, if you love to design and don’t see any obstacles to realizing your ideas, follow the tips below and you will succeed without any doubt.
Using a screwdriver
One of the simple options is to make an electric scooter with your own hands from a screwdriver. In this way, it is unlikely that you will be able to make a powerful and high-speed scooter. But this is undoubtedly the most accessible and cheapest option. For this you will need:
- Screwdriver;
- Regular scooter;
- Bicycle chain;
- Bicycle sprocket;
- Wires.
The sequence of actions is as follows:
- A bicycle sprocket is rigidly attached to the rear drive wheel.
- A small drive sprocket is made of metal, which is clamped into a screwdriver.
- A screwdriver holder is made from square pipes or corners.
- The holder is attached to the frame using bolts or rivets. The holder must be attached in such a way that it is possible to adjust the chain tension.
- The bicycle chain is measured and cut to size.
- A control button is attached to the handle.
This option is good because you don’t need to place the entire device next to an outlet to charge.
The battery is simply removed from the screwdriver and placed in a standard charger. There is also no risk of fire or explosion of the battery from overcharging.
Making a connection
When connecting all the equipment, you need to make sure that the wires are not pinched anywhere and do not rub against the metal.
Here he is - our handsome man!
Conclusion
That's all! Our homemade electric scooter made from a regular scooter is ready for use! Of course, the master who built this vehicle, as they say, is on point, but this does not mean that you will not succeed in exactly the same way, and maybe even better!? Before starting the process, carefully weigh the pros and cons, and only then get down to work. Naturally, it will be very good if someone knowledgeable in such events helps you.
So, feel free to try your own execution options - it worked for others, it will work for you too! Do not worry!
Recommendations
Making an electric scooter with your own hands is not a very complicated process, it is creative and interesting. On the Internet you can watch a video on how and what you can use to realize your idea.
As a result, it is possible to make a device of an unusual design with outstanding technical characteristics. There may be mistakes and failures along the way. It is worth noting that a homemade version may not always be cheaper than a factory one.
It all depends on what materials and parts to use. However, repairing a do-it-yourself electric scooter will definitely be easier, because you will know all the parts and components.
And you yourself are responsible for their reliability. After all, if you repair a scooter purchased in a store yourself, this may void the factory warranty.
When making an electric scooter, it is important to consider such points as frame strength and engine power. Its rated voltage and current. Select the correct controller and battery based on engine parameters.
It is necessary to protect the battery pack from damage. It is also worth taking care of the moisture protection of all electrical elements and connections to avoid short circuits. You should refrain from using an electric scooter in rainy weather.
What do you want from your vehicle?
First of all, we decide what exactly we need? A bulky device equipped with inflatable wheels, offering its owner a high level of power, with the ability to cover considerable distances, while wrapping asphalt around the wheels? Or a lightweight folding design that can be carried with one hand without much strain and used for commuting to work, and for other places, such as a fitness club, bypassing stuffy and sometimes infrequent public transport?
Here is an example with a folding design. To bring our plans to life, we will need a folding scooter with a rear shock absorber. The product will need to change the rear fork to a wider one and, in addition, adapt the MK there. Naturally, you will need to purchase a controller, as well as a battery, integrate all this wealth into our homemade self-propelled gun and, of course, connect it correctly.
We choose a scooter for our transformations. You won’t have to tinker for a long time, since the choice is extremely scarce. Previously, the ubiquitous Chinese developed a scooter frame equipped with a two-suspension system and on its basis, manufacturers began to assemble various modifications of scooters and it is this “cart” that we will need.
The more expensive the structure, the better its quality, in theory. A folding frame with a suspension mechanism cannot please the user with reliability in principle, but we don’t really have a choice.
An electrified scooter will “delight” its owner with the same misunderstandings as an ordinary unit, so you need to prepare for these troubles in advance. An electric scooter's moving components will also become loose, creak, and make noise.
The more moving parts your device has, the more carefully you need to monitor them. This rule applies equally to both purchased folding scooters and those created by hand. Why then do we give preference to a gadget with a suspension? And then, first of all, the rear fork and wheel need to be replaced.
DIY photo of electric scooters
Ready electric bike
The easiest and most reliable way to buy a ready-made electric bike is to get acquainted with the 3 most popular ones at the moment:
— Eltreco FS-900 26;
— HOVERBOT CB-4 X-Rider;
— WELT Rockfall 1.0 E-drive.
WELT Rockfall 1.0 E-drive
This is a 2022 model, costing 50-55 thousand - the most affordable option of those being considered. Class: mountain, cross-country.
The battery is 13 Ah, the sizes are varied, you can buy for riders from 150 cm or more.
The stock tires are quite grippy, even when driving on rough terrain. Among the shortcomings are weak brakes.
Eltreco FS-900
Double suspension from the budget price category - only 65 thousand. Class: cross-country, launch year: 2022.
It has a fairly capacious battery that can pull the rider up to 50 km.
Charging time – up to 6 hours. The backlight is integrated, and the front light is powered by a battery, and the rear light is powered by a small solar panel. Some users complain that the rear shock absorber is stiff, but it is not difficult to replace.
Electric scooter made from a screwdriver.
There are a lot of interesting videos on the Internet, and while watching videos on YouTube once again, I came across a review of the RAZOR . I wondered how popular this type of transport is. After surfing the Internet, it turned out that this is a very common thing. Later, while relaxing on the Azov Sea in the city of Yeysk, I saw with my own eyes an industrial Chinese electric scooter with wide wheels with brake discs. Apparently those with large batteries and the charge lasts for 40 km. I was amazed by the powerful frame. A kind of small moped))))). The price of scooters is captivating. From 12,000 for a scooter with an electric motor power of 350W. But I didn’t stop there and found several articles on homemade electric scooters. I really liked the idea of a homemade electric scooter from a screwdriver and decided to create my own scooter from plywood. And I used some kind of Austrian screwdriver. It was a cordless drill/screwdriver with an impact and a 24V battery. I got it for free. Of course, it was scary at first, I had doubts whether the engine power would be enough to carry my 78 kg of live weight))), but it turned out to be so much that I couldn’t hold the scooter even when resting on the asphalt, the wheels began to slip.
I started making this miracle by assessing the size of the scooter by eye, placing my daughter’s children’s toys on the floor. Then I decided on the size of the wheels of the future scooter. As far as I remember, 140mm in diameter. I ran to the “Everything for the Garden” store and bought 2 wheels for 180 rubles each. Then I glued together several A4 sheets to mark the parts in real scale. On it I laid out the wheels, drew the base and depicted the entire scooter in profile, life-size. Then from it I transferred images of individual parts to other sheets and glued them onto plywood. And I cut out the details directly from them.
My design also includes 40x50 timber. It serves to strengthen the platform on which a person stands. Since the scooter is made of 8mm thick plywood, the platform is very long and carries a decent amount of weight. And besides, it lies flat, without reinforcement it will break even under a baby. It still sags a little at the edges to this day. There are plans to eliminate this, but at the time of writing, these are just plans. The timber was tested for strength in a barbaric way. He cut me the length I needed, placed one edge on the threshold of the bathroom, and the other on the floor. It turned out to be 2 support points on the sides. The middle was completely in the air. I took my little daughter and together we jumped as best we could in the middle of the beam. Not only did it survive, but it didn’t even crunch.
The steering wheel is made of a tube presumably of titanium origin, since aluminum and duralumin do not have such strength. At the end of the handle under the right hand there is a variable resistor responsible for the speed of the scooter.
A small board with a k561la7 microcircuit is soldered to the resistor at the back. I have a home-made shim implemented on it and it’s all located right in the steering wheel. But I used a 60A IGBT power transistor, since 3 IRFZ44Z field switches failed immediately)))). You will probably think that I forgot to install a reverse surge diode in parallel with the motor, but you would be mistaken if you think so. I can only guess that the transistors were knocked out due to direct voltage surges, since these field devices are only designed for 40 volts. It's difficult to shock them, I paralleled them. But I had a good IGBT, because it is designed for 600V. But one day, after gasping on the sand, it struck. At first I was perplexed, how did this happen? Could he really not withstand the current? But everything turned out to be more banal. My motor is not protected by anything, and a protective diode is soldered to its terminals. And then I noticed that this bastard had fallen off with one leg of the engine. I decided not only to move it to the board (for greater reliability, so that it would not fall off anymore), but also to change the control to a push-button one. After all, as practice has shown, it is not convenient to twist the gas while driving, this is not a motorcycle. Although maybe I just made an inconvenient gasulka. But the push-button one is more original and functional; I’ll attach dynamic braking to it. And in the future, create an on-board computer. After all, the MK will already be ready. Yes, yes, it is he who will be entrusted with controlling the IGBT transistor based on signals from the buttons. And also close the transistor before turning on the dynamic braking relay. I want to use a car relay; they have a fairly high switching current and are affordable.
In general, I only program PIC microcontrollers, but I have long wanted to try my hand at AVR. So the idea came to my mind to use the AT90S1200 I had lying around. Moreover, this is already an antique item. But at the time of writing, these are only plans. For now I will describe everything that is now.
I bought the batteries one-on-one with an uninterruptible power supply for 7A/H and 12V. Two pieces cost me 1400 rubles. These batteries are gel batteries. At one time, I read a lot about them before purchasing. The main selection criterion was that they can be charged at home without fear of harmful fumes. My homemade charger for a car battery turned out to be useful, because it is also automatic, and gel batteries really don’t like overcharging. I charge them with a current of 500mA. I have never ridden with fully charged batteries. But presumably they will be enough for 40 minutes of intense driving. I won’t say anything specific about the mileage either, but it is clearly less than we would like))). 10 kilometers is the limit. It’s a pity my smartphone died, at least check with GPS how fast it’s going.
