Almost all buyers ask questions about the service life and operation of CityCoco electric scooters. In this regard, starting from 2018, each of our electric scooters will be accompanied by an instruction manual with detailed recommendations for extending its service life. For those who bought an electric scooter from us earlier, or for those who bought/will buy it elsewhere, we specially wrote this blog to answer the most frequently asked questions:
- How long does the battery last? How to extend its service life?
- How to properly charge the battery? Should it be completely discharged before charging it?
- How to properly store the electric scooter / battery in winter?
- Where is the electric motor, how long does it serve?
- What can damage an electric motor, how to use it correctly?
CityCoco electric scooters use li-ion rechargeable batteries having at least 80% of the original capacity after 500 cycles (full charges and discharges). After that, the battery will continue to work, just its capacity will gradually decrease. That is, with proper operation, for example, if an electric scooter travels 100 km on a single charge, your battery will last at least 50,000 km of total mileage. And even after that, it will serve for some time, but the power reserve will gradually decrease.
These calculations are relevant only for high-quality li-ion batteries. Now there are many cases on the market when the seller or his supplier save money and install a poor quality battery. If you have not bought an electric scooter yet, we strongly recommend reading this article to avoid a bad purchase.
Battery life (number of cycles) can be either reduced or increased under certain operating conditions.
Li-ion batteries do not have a memory effect, so there is no need to specially discharge the battery to the end before putting it on charge.
It should be remembered that a full charge and discharge will wear out the battery faster, while incomplete cycles, on the contrary, prolong its life (see table 1).
Table 1. Service life (number of cycles) depending on the depth of discharge
|Discharge depth||Number of discharge cycles|
Therefore, whenever possible, charge the battery while it is still running.
When the battery is completely discharged (the electric scooter has turned off and does not turn on), put it on charge as soon as possible.
Also, do not leave the electric scooter on charge for more than a day.
Despite the fact that incomplete cycles prolong the life of the battery, it is still recommended to fully charge the battery at least one of 5-10 times and then leave it connected to the charger for several hours. A battery consists of a large number of small batteries, the voltage of which must always be the same. When the battery is discharged, there is a slight difference in voltage on each of the cells, but for this there is a balancing board, which, at the end of the charge, equalises the voltage on all cells. If you never charge the battery to the end and do not let it equalise the voltage, then its resource will decrease!
Keep in mind that using a very long or poor-quality extension cord can reduce the mains voltage, and therefore the voltage at the charger output, which can lead to an incomplete battery charge and the impossibility of starting the balancing process.
High charging current at temperatures below 0 ° C may reduce battery life. If you have a need to charge your electric scooter in subzero temperatures, contact our store and we will sell you a charger with a small charge current.
The electric scooter can be operated at temperatures from -20 to +45 ° C. At temperatures below 10 ° C, the power reserve can be reduced by up to 40%, this is normal. It is also possible to completely turn off the electric scooter on the move under a heavy load, while the charge indicator at rest can show another 40-60% of the charge, therefore, in the cold time of the day, be guided by the battery charge indication in motion, under load.
If you are not going to use the electric scooter in the cold season, (3-5 months) charge the battery to 60-80% of its capacity, and if possible, turn it off. When connecting the battery to the power circuit, a spark will occur, this is normal. There is no need to recharge the battery during this period of time. If the electric scooter is more than 5 months old, the battery needs to be recharged to maintain the battery charge within 60-80%.
If you are going to store the electric scooter for a long time in a cold place, but want to save its battery with a minimum loss of resource, know that lithium-ion batteries are best stored at a temperature of about +5 ° C. The higher it is and the closer the state of charge is to 100%, the faster the battery ages and loses capacity (see table 2). If it is removable, it is best to charge it to 60–80%, remove it from the apparatus, pack it in a sealed plastic bag, put it in the refrigerator (but not in the freezer!) And recharge it periodically. If the battery is not removable, in any case do not take it out, it is glued, and you can tear its sealed cover, which will quickly damage the battery due to moisture ingress. Batteries can be stored at temperatures down to -20 ° C, but charged at temperatures above 0 ° C, so make sure that the temperature is not disturbed before charging.
In both cases, after long storage, before use, be sure to charge the battery to the end, without disconnecting the charger from the mains for at least 2 hours, or better - up to 10 hours. This is necessary for the battery balancing process.
Table 2. Degradation of the characteristics of lithium-ion batteries due to storage temperature and state of charge
|Temperature, °C||40% charge level||100% charge level|
|0°C||98% after 1 year||94% after 1 year|
|25°C||96% after 1 year||80% after 1 year|
|40°C||85% after 1 year||65% after 1 year|
|60°C||75% after 1 year||60% after 1 year|
But there is another factor that can greatly affect the battery life and the BMS control board. This is your riding style and can cause your battery to heat up constantly. Especially if you have one. There is nothing wrong with hitting full throttle if you need to drive up a steep hill, overtake, etc. For 5 minutes of continuous maximum load, the battery will not have time to heat up. But if you intentionally, without any need, constantly accelerate / slow down the entire discharge cycle, bury the electric scooter in sand, etc., then the battery may heat up above critical temperatures and its service life will decrease
By following the above guidelines, you can extend the battery life of your electric scooter.
The electric motor in CityCoco is installed in the rear wheel. It is brushless and does not have any rubbing elements, with the exception of bearings. Thus, the wheel motor is a reliable, durable design. It consists of:
- a stator with windings, which is an electromagnet;
- a rotor with magnets, which is part of the wheel itself and rotates around the stator;
- Hall sensors (transistors), which allow you to determine the position of the wheel relative to the axis;
Bearings, like Hall sensors, have a fairly long service life, but even in the event of a failure, they are quite inexpensive and are relatively easy to change. Neodymium magnets are the most powerful magnets ever developed. The grip strength of neodymium allows them to hold 50-100 times their own weight. Such magnets lose no more than 1% of their magnetisation over 10 years, which indicates their high stability, while they lose their properties at high temperatures. Therefore, the motor-wheel will only serve for a very long time if it is used correctly.
Why does the electric motor heat up?
If you are the owner of CityCoco purchased from us since 2019, then you have a thermal sensor installed by us in the engine/controller, which will stop the scooter in time and prevent you from damaging these parts.
The continuation of the blog was written for those who do not have overload protection, namely, all other CityCoco owners, since no Chinese factory puts temperature sensors in the engine / controller on these scooters.
The electric motor has a parameter such as rated power. This is the power at which it works for an unlimited amount of time and does not heat up. Since CityCoco electric scooters are mostly unbranded, the Chinese are silent about the real power rating of the motors used. In order to save money, they put a weaker motor than it should be with the installed controller, and make it work at its limit. And on the cover of the electric motor they write long-term power, or even peak power.
Long-term power is the power at which the engine heats up, but not enough to burn out, and can work in this mode for a sufficiently long time, for example an hour.
As a rule, this is the power consumed by the electric scooter when driving at maximum speed, provided that one passenger is traveling and there are no other loads in the form of additional. weight, flat tires, etc. Otherwise, in the presence of such factors, energy consumption will increase and the electric motor will begin to work for a long time already at peak power, which is unacceptable
The peak power can be several times higher than the nominal, but at the same time, the electric motor can work under such a load without destruction for tens of seconds.
For a CityCoco electric motor with 1000W long-term power, this is usually 1800W. Reaching peak power is needed so that at the right moment you can go up a steep mountain, accelerate sharply in an emergency, etc.
If you abuse the excess of the permissible load on the electric scooter, namely, create such conditions that the peak power will be supplied to the motor for minutes or even tens of minutes in a row, this can lead to a loss of properties of neodymium magnets, a drop in the efficiency of the electric motor and to burn out the stator windings.
Therefore, pay attention to the temperature of the electric motor after extreme driving, overcoming steep climbs, with a second or third passenger, and other factors that cause increased load. Engine temperature can be controlled by touching the wheel rim with your hand. It should be warm. If the engine is so hot that it is uncomfortable for you to hold your hand, you need to allow it to cool down and then operate it in a more gentle mode. If the engine is constantly heated above 100 degrees, its service life can be significantly reduced.
If the efficiency of an electric motor, for example, is 80%, this means that the remaining 20% of the power supplied to it is spent on heating. Accordingly, 200W out of 1000W will heat up the iron core, which is not much for such a volume of iron. But the efficiency of the electric motor changes depending on the speed of rotation, while the manufacturers indicate the maximum efficiency at certain speeds. The table below shows the dependence of the efficiency on the speed and type of load of electric motors of one of the best Chinese brands QSMOTORS.
Table 3. Dependence of efficiency on the type of load and speed of the QSMOTORS electric motor
Based on the data in the table, you can see that the efficiency has the lowest value at idle. But this is not important for us, it should be noted that the efficiency decreases significantly at the start at low rpm. In this case, a motor with a long-term power of 1000W (and the nominal power can be 1.5-2 times less) consumes a peak power of 1800W, of which 70% (1260W) is spent on heating it. This happens when starting from a standstill to a speed of 10-15 km/h, climbing a steep hill, when driving in deep sand, etc. It's okay if the engine experiences such loads for a short time.
Our tests have shown that once a typical engine starts to reach critical temperature, it takes 10-15 minutes of continuous engine load to warm up. During normal driving, the electric scooter does not experience such loads, but fans of extreme riding should be careful. Also, be sure to control the tire pressure. Driving with flat tires significantly increases the load on the engine, which can lead to overheating. The recommended tire pressure is at least 1 atmosphere for a passenger weighing 70 kg, 1.6 atmospheres for a weight of 100 kg, and 2.3 atmospheres for a weight of 150+ kg.
For the most efficient use of energy, it is recommended to drive at a speed higher than 50% of the maximum speed. With a decrease in the number of revolutions, the efficiency of the electric motor drops, which can be seen in the technical characteristics of the electric motor::
Table 4. Full technical characteristics of the QSMOTORS engine
The values we need are highlighted in red. The maximum engine speed is 508.9 rpm, and the range in which the efficiency does not fall below 80% is from 267 to 501.7 rpm. At rpm below 267 rpm, the efficiency begins to decline.
Therefore, the probability of engine overheating is highest not when driving at high/maximum speed, but when driving at low speed, if at the same time it is experiencing a large load.