The unit of battery capacity is Ah (ampere-hour), which is the product of current and time. A 100AH battery, after being fully charged, can be discharged completely in one hour at a current of 100A. A 50A current would discharge it completely in 2 hours! 20A would discharge it completely in 5 hours! Of course, these are theoretical values; in reality, it's impossible to discharge at a constant current indefinitely. This is because the battery's internal resistance increases as the battery capacity decreases, the terminal voltage gradually decreases, the discharge current decreases, and eventually the terminal voltage becomes 0 (at which point it has become over-discharged). Over-discharge is lifelong harmful to the battery. If a fully discharged battery is not recharged in time, the strong acid adhering to the plates will corrode the plates within a few hours, ultimately rendering the battery unusable. Therefore, most circuits have battery protection circuits that automatically cut off power once the battery voltage drops below 10.8V to prevent damage from over-discharge. (A nominal 12V battery has six internal cells.) Using the battery's discharge current multiplied by the discharge time to express how much energy a battery can store is a very intuitive method of measurement. A higher ampere-hour rating indicates that the battery can store more energy. However, this does not mean that the battery can discharge with such a large current.
The amount of electricity a battery can discharge or the duration of discharge under specified conditions (including discharge intensity, discharge current, and discharge termination voltage) is called battery capacity, measured in Ah or Amin. A car battery is a reversible DC power source that can convert chemical energy into electrical energy and vice versa; it is connected in parallel with the alternator.
During engine startup, it supplies power to the starting and ignition systems.
It supplies power to the car's electrical equipment when the engine is stopped or idling at low speed.
When the demand for electricity exceeds the output of the charging system, it will provide the current for a limited period of time.
The battery also absorbs transient overvoltages in the circuit to maintain the stability of the vehicle's electrical system voltage and protect electronic components.
If a car battery is left unused for a long time, it will slowly self-discharge until it is unusable. Therefore, the car should be started periodically to charge the battery. Another method is to disconnect the two terminals of the battery. Note that when disconnecting the positive and negative terminals, the negative terminal should be disconnected first, or the negative terminal should be disconnected from the car chassis. Then disconnect the other terminal marked with the positive (+) mark. Car batteries have a limited lifespan and need to be replaced after a certain period. When replacing the battery, the same order should be followed, but when reconnecting the terminals, the order is reversed: connect the positive terminal first, then the negative terminal.
When the ammeter indicates insufficient battery power, charge the battery promptly. The battery's charge level can be displayed on the dashboard. Sometimes, if you find the battery is low while driving and the engine stalls and won't start, as a temporary measure, you can ask other vehicles for help and use their batteries to start your car. Connect the negative terminals of the two batteries together and the positive terminals together.
The density of the electrolyte should be adjusted according to the standard based on different regions and seasons.
When the electrolyte level is low, add distilled water or a special electrolyte solution and a nano-carbon sol battery activator. Never use purified drinking water, as it contains various trace elements that can negatively impact the battery.
Continuously using the starter motor while starting a car can damage the battery due to over-discharge. The correct procedure is to limit each starting attempt to no more than 5 seconds, with at least a 15-second interval between attempts. If the car still fails to start after multiple attempts, the cause should be checked in the electrical system, ignition coil, or fuel system.
During daily driving, you should regularly check whether the vent holes on the battery cover are clear. If the vent holes are blocked, the generated hydrogen and oxygen cannot escape. When the electrolyte expands, it can rupture the battery casing and affect the battery's lifespan.
Check the positive and negative terminals of the battery for signs of oxidation. You can also frequently pour hot water over the battery cable connections.
Check all parts of the circuit for signs of aging or short circuits to prevent the battery from prematurely malfunctioning due to over-discharge.
1. Over-discharge
2. The battery has been stored for an extended period of time (without being charged during storage).
3. Cannot be charged via car engine.
4. No electrolyte
5. Electrolyte specific gravity is too high
6. Charging under high temperature conditions
7. Contaminated by pollutants (e.g., hydrochloric acid, seawater, organic acids, etc.)
8. Applying excessive current while charging the battery.
9. Deformation of the electrode plates causes the positive electrode plate to come into contact with the cladding plate, resulting in a short circuit.
10. Deposits deposited on the upper and lower parts of the electrode plates can cause short circuits.
11. By avoiding the above points, the lifespan of your battery will be extended accordingly.
Battery capacity is one of the important performance indicators for measuring battery performance. It represents the amount of electricity that the battery can release under certain conditions (discharge rate, temperature, termination voltage, etc.) (discharge test can be performed using JS-150D), which is the battery capacity. It is usually measured in ampere-hours (abbreviated as A·H, 1A·h=3600C).
Battery capacity is classified into actual capacity, theoretical capacity and rated capacity according to different conditions. The formula for calculating battery capacity C is C=∫t0It1dt (integrating the current I over the time interval from t0 to t1). Batteries have positive and negative terminals.
Battery capacity is classified into actual capacity, theoretical capacity, and rated capacity according to different conditions.
The minimum capacity that a battery can withstand when discharged to the termination voltage at a certain discharge rate and 25°C is the capacity specified during the design and production of the battery. This is called the rated capacity at a certain discharge rate RH.
Square lithium-ion batteries
Battery capacity is generally calculated in Ah (ampere-hours), or in watts (W) per cell (unit of plate). (W/CELL)
1. Ah (ampere-hour) calculation: Discharge current (constant current) I × Discharge time (hours) T. For example, a 7AH battery can continuously discharge for 20 hours if the discharge current is 0.35A.
2. The standard charging time is 15 hours, and the charging current is 1/10 of the battery capacity. Fast charging will reduce battery life.
Battery capacity refers to the amount of electrical energy a battery can store. The unit of battery capacity is "mAh," which stands for milliampere-hour (in terms of large-capacity batteries such as lead-acid batteries, "Ah" is commonly used for convenience; 1Ah = 1000mAh). If a battery's rated capacity is 1300mAh, meaning it's discharged at a current of 130mA, then the battery can operate continuously for 10 hours (1300mAh/130mA = 10h). If the discharge current is 1300mA, then the power supply time will only be about 1 hour (actual operating time varies depending on the battery's actual capacity). This is an analysis under ideal conditions. The current of digital devices during actual operation cannot always remain constant at a certain value (for example, in a digital camera, the operating current will vary significantly due to the on/off state of components such as the LCD screen and flash). Therefore, the time a battery can power a device is only an approximate value, and this value can only be estimated through practical operating experience.
