As soon as winter comes, there will be electric bicycle users who complain that the "little electric donkey" does not run as far as in summer, and always feel that there is a problem with the battery, so what is the reason for this?
Why does the range of e-bikes decrease?
# From the aspect of winter charging saturation #
In general, the best operating temperature of the battery is about 25°C. In winter, the temperature is low, the battery is in a low temperature environment, the battery cycle capacity is relatively low, the viscosity of the electrolyte increases, the chemical reaction resistance increases, the charging capacity is 60%~70%, the discharge amount is 50%~60%, and the driving mileage is reduced. Therefore, even if you buy a new electric bicycle, there will be a problem of poor battery life in winter.
The "Lithium-ion Battery for Electric Bicycles" (GB/T 36972-2018) stipulates that the cycle life of the electric bicycle battery pack should not be less than 600 times.
# Analysis from the aspect of discharging when the battery is working in winter #
When the temperature is about 25 °C, the lead-acid battery can store electricity normally and discharge to the maximum extent, and when the temperature drops below 10 °C, the power stored by the lead-acid battery will automatically decrease by about 20%. Below 0°C, the stored power decreases even more, so there is less power to be able to ride on.
Common types of e-bike batteries
"Batteries and chargers for electric bicycles - Part 1: Sealed lead-acid batteries and chargers" (QB/T 2947.1-2008) stipulates that the fully charged battery is placed in an environment of (-10±1) °C for 10h to test the low-temperature discharge capacity, and its capacity should not be less than 75% of the rated value.
# Other reasons #
Of course, there are other common factors that electric bicycles can't run far in autumn and winter, not necessarily battery problems, if you are more worried about being affected by other aspects, you can go to the repair shop for a comprehensive test.
A common factor that an e-bike can't run far
In 2023, the Shanghai Municipal Administration for Market Regulation will conduct a supervision and random inspection of the quality of electric bicycles produced and sold in the city. This time, 20 batches of products were randomly inspected. After inspection, there were 3 batches of unqualified batteries, mainly chargers and batteries (battery tamper-proof) items.
The "General Technical Specification for Electric Bicycles" (GB 17761-2018) standard mentions that the tamper-proof battery of electric bicycles should meet the following requirements:
Dealers and consumers should avoid expanding and modifying the battery of electric bicycles, as excessive battery voltage or current will cause harm to the human body or cause fire.
Precautions for use
When using an e-bike in winter, it is recommended to pay attention to the following points, which can make the e-bike run farther and safer
Select the appropriate charging environment
In autumn and winter, do not bring the battery into the home indoor charging, it is recommended to choose a professional charging place with a relatively high temperature, which can be carried out in the community public charging carport, appropriately extend the charging time, and increase the floating charge of 1~2 hours (the charging time is generally not more than 10 hours), so as to enhance the storage capacity of the battery and extend the driving distance.
Choose the appropriate charging method
In winter, the power drops rapidly, so it should be charged in time to ensure that the power is sufficient. If the battery is not optimal, riding at a loss of power may lead to over-discharge, which can cause fatal damage to the battery. If you don't use the e-bike for a long time, it is recommended to charge it once a month or so.
Develop good riding Xi
In the case of slippery road surfaces in winter, a moderate reduction in driving speed can reduce the frequency of braking and acceleration, thereby reducing the load on the battery. It is recommended to maintain a constant speed and drive smoothly as much as possible, and avoid operations such as sudden braking and sudden acceleration. Sudden braking, sudden acceleration, overload, etc. will increase the discharge current of the battery and accelerate the consumption of battery power.
Timely maintenance
In winter, due to the decrease in temperature, the tires will stiffen and the coefficient of friction will decrease, which will affect the stability and safety of riding. It is recommended to regularly check whether the air pressure of the tires is sufficient, check the sensitivity of the brakes, and perform regular maintenance on the e-bike.
Source: Shanghai Market Regulation
Editor: Cheng Qian
Editor-in-charge: Wang Bo