Xiaoniao Electric Vehicle Battery Usage and Maintenance: 
　　
Electric vehicles widely use maintenance-free lead-acid batteries as power sources. Batteries are easily damaged components and are expensive. Therefore, correct usage and maintenance of the battery to extend its lifespan is very practical. This article discusses the use and maintenance of lead-acid batteries, based on their characteristics, for your reference. 
 

I. Battery Capacity and Lifespan 
Capacity and lifespan are the main indicators for measuring a battery. Capacity is the battery's ability to store energy, generally expressed in ampere-hours (Ah). For example, a new 36V battery pack nominally rated at 12AH must, according to industry constraints, discharge at 6A to a termination voltage of 31.5V for no less than 2 hours. When using this battery in an electric vehicle with a 75kg load, riding on flat roads, the operating current is approximately 4A, the discharge time should be greater than 3 hours, at a speed of 20 km/h, with a theoretical range of 60 km. 
Lifespan indicates the decline in battery capacity. According to the newly formulated standard for electric vehicle batteries, the battery lifespan is expressed as the number of charge-discharge cycles at 70% of the rated capacity, with a minimum acceptable value of 350 cycles. Provided the motor, controller, and charger are all in good condition and the usage method is appropriate, a high-quality battery pack should last no less than one year, generally up to one and a half years, and with proper maintenance, up to two years. 
 

II. Factors Affecting Battery Lifespan 
Generally, the factors affecting battery lifespan can be divided into: the battery's own performance and quality, factors related to its use in the electric vehicle, and the user's usage habits. In the electric vehicle system, the two main factors affecting battery lifespan are the motor's efficiency and the charger's design. If the motor's efficiency range is narrow, power consumption increases, frequently operating in a low-efficiency range, and the motor's internal temperature can easily rise. When temperatures are high, the magnetic materials will undergo irreversible demagnetization. Over time, the efficiency will further decrease, resulting in a vicious cycle where the electric vehicle's power consumption increases significantly, and replacing the battery doesn't help. The wear of components such as brushes, planar converters, and the reduction system will also lead to reduced motor efficiency. 
Therefore, a better performing motor should be chosen, and attention should be paid to maintaining worn parts. The charger is also very important for the battery. A good charger ensures better charging effects and electrical safety. Currently, the chargers used in electric vehicles are dedicated chargers that match the rechargeable batteries. Charger circuits all use special integrated circuits, with features such as integrated switching circuits, constant voltage constant current charging, pulse charging, and automatic power-off protection. 
 

III. Precautions When Using the Battery 
1. Correct use of the charger: 
(1) Ensure the AC mains voltage matches the charger's input voltage. 
(2) Ensure the charger's output voltage matches the battery's rated voltage. 
(3) First plug the charger into the battery box, then plug in the AC power plug. After charging is complete, unplug the AC power plug first. 
(4) A red indicator light indicates normal charging. When charging is complete, the indicator light changes from red to green. 
(5) The charger should be used indoors and should be kept dry. Avoid dropping or bumping it. It is recommended not to place the charger in the electric vehicle's trunk to prevent vibration and jolting. During charging, do not cover it. Place it in a well-ventilated and heat-dissipating place, otherwise, it may affect the charger's lifespan and charging state, and damage the battery. 
 

2. Charge as needed. Storage batteries are most afraid of being depleted. Regularly keeping the battery fully charged can extend its lifespan. It is recommended to fully charge the battery every night after use to ensure a full charge for the next day's use. Lead-acid batteries do not have a memory effect, but frequently discharging them before charging significantly impacts their lifespan. When charging, the charger's indicator light generally turns from red to green. After the light turns green, float charging for 2 hours is recommended, which helps inhibit battery sulfation. 
 

3. Prevent overcharging. Overcharging a battery is very harmful. It produces a large amount of gas that erodes the plates, accelerating the loss of active material on the plates and shortening the battery lifespan. It also causes water evaporation, drying of the battery, and increased temperature, leading to thermal runaway, plate expansion, and deformation of the housing. It also causes sulfation of the plates, reducing battery capacity and even causing failure. 
 

4. Prevent over-discharging. Using the electric vehicle skillfully can also extend the battery lifespan. First, prevent high-current discharge. When starting, going uphill, or riding against the wind, try to use pedal assistance. Second, prevent prolonged discharge. For example, if the theoretical range of a new battery is about 50 kilometers, it is best not to travel long distances during use, and the discharge amount should not exceed half of the total battery capacity. Long-term deep discharge will inevitably affect the battery's lifespan. 
 

5. Prevent depletion. For batteries that are left unused for a long time, charge them once a month. Generally, it is best to continue float charging for 5 hours after the charger's light turns from red to green. 
 

6. Maintenance. Although electric vehicle batteries are maintenance-free, after half a year of use, as water is constantly consumed, the capacity begins to decrease. If distilled water is added for maintenance, the battery's lifespan can be significantly extended. The specific method is as follows: Open the battery box lid, remove the battery, unscrew the valve cover, and inject battery-grade distilled water into each hole. The amount of water added to each cell should be strictly consistent, generally just enough to submerge the separators. Then charge without covering the valve for 6 hours, screw on the valve cover, and place the battery back into the box for continued use. 
 

When you notice a significant reduction in battery capacity, you should have it inspected and maintained by a technical service department. When replacing the battery, you should have a professional technician diagnose the motor's wear. If necessary, replace the brushes or other worn parts and the lubricant. During daily use, pay attention to whether the brakes are working properly to avoid excessive power consumption. If you follow the above points, your electric vehicle battery lifespan will be greatly extended. 
 
Electric Vehicle Component Knowledge 
 
Controller 
The controller is the component that controls the motor speed. It is also the core of the electric vehicle's electrical system and has undervoltage, current limiting, or overcurrent protection functions. Intelligent controllers also have multiple riding modes and whole-vehicle electrical component self-test functions. The controller is the core component for energy management and various control signal processing in the electric vehicle. 

Usage Tips: The controller's main control board is part of the electric vehicle circuit, has a large operating current, and generates considerable heat. Therefore, the electric vehicle should not be parked in direct sunlight, nor should it be left out in the rain for extended periods, to prevent controller malfunction. 

Usage Tips: The electric wheel hub usually requires no special maintenance. Professional maintenance is only needed after the electric vehicle has accumulated 2000 hours of operation. This includes checking the wear condition of the motor carbon brushes, the wear condition of the deceleration mechanism, and replacing the mechanical system lubricant, etc. 

Battery 
Avoid overloading and overweight driving (such as carrying passengers or loading heavy objects): If the meter shows insufficient power during driving, use manual cycling, because deep discharge greatly reduces battery life. 

Avoid emergency braking: Frequent emergency braking will affect braking flexibility and consume battery capacity. In addition, the speed should not be too fast, because the faster the speed, the greater the battery consumption. 

Many electric vehicle owners have found that the distance traveled after a single charge has become shorter, but the battery is fine after inspection. Experts explain that this is all caused by low temperatures. 

Electric vehicles generally use valve-regulated lead-acid batteries. 25 degrees Celsius is its optimal discharge temperature. When the temperature drops, the discharge time will be shortened. 
Some users have found that after the battery is undervoltage, after 10 minutes, the battery is not undervoltage again, so they use it again. This is more damaging to the battery, and most vehicle manuals do not warn users. 

Charger 
When charging, be careful not to use chargers from other Brands. Each Brand's charger and battery performance are matched. Only a dedicated charger can achieve the best charging effect. 
Motor 

Currently, electric vehicles mainly use three types of motors: 
(1) Brushed high-speed motor. The motor has high efficiency, strong overload climbing ability, large starting torque, and outputs power after deceleration through a speed-changing gear device. It has noise. 
(2) Brushless low-speed motor. Without a speed-reducing gear device, it has the advantages of maintenance-free and no noise. However, the controller is complex, the starting current is large, and the overload climbing ability is poor. 
(3) Brushed low-speed motor, without a speed reducer gear device, simple structure, low cost, poor starting uphill overload capacity, and high power consumption.