The volumetric energy density is equal to the capacity of the lithium battery multiplied by a ratio of 3.6. The mass energy density is equal to the battery capacity multiplied by a ratio of 3.6 of the battery weight. According to the energy storage network query, lithium batteries commonly use lithium battery parameter calculation formulas. The capacity of lithium batteries is determined by the amount of active material in the battery, which is usually expressed in milliamp-hours.
If a 12V9000mAH lithium battery is used for 5V, is the equivalent capacity 12*9000÷5? Is this how it is calculated? Assume the conversion efficiency is 100%
Capacity C = discharged battery (constant current) I × discharge time (hours) T.
Battery capacity is one of the important performance indicators to measure performancedrums. It indicates the quantity of electricity released by the battery under certain conditions (discharge rate, temperature, termination voltage, etc.). (can be carried out with the JS-150D discharge test), that is, the battery capacity, usually in ampere-hours (abbreviated, expressed as A·H, 1A·h=3600C).
The battery capacity is divided into actual capacity, theoretical capacity and rated capacity according to different conditions. The battery capacity C is the integral of the current I from t0 to t1, and the battery is divided into positive and negative poles.
What is the specific energy and capacity of lithium-ion batteries?
According to your assumption that all capacities and efficiencies are 100%, this can be easily understood. For example, the power of a 12V battery is 12V*9Ah=108W. For example, when a 5V electrical device is used to charge a 5V lithium battery (5V power1200mAh 5V*1.2Ah=6W), the capacity is equivalent to 18 times. that of a 5V battery. But in reality, the 12V lithium battery only has an effective working voltage of 11.1V, and the power P = 11.1V * 9Ah = 99.9W. When converted to 5V, it can only be output at 4.2V, and the power is only 4.2V. 83.9W. The efficiency is only about 77.7%. When charging a 3.7V 1200mAh battery, the actual power can only be calculated as 83.9 x 3.7/4.2 = 73.9W (the power of a lithium battery 3 .7 V is 3.7 V x 1.2 Ah = 4.44 W). The efficiency is only 68.4% of the rated calculation, but using it to replace the 3.7V*1200mAh lithium battery, the capacity increases by 16.6 times with the same usage.
Specific energy refers to the battery's energy (in watts) divided by its weight. Usually above 120. The higher the specific energy, the higher the battery efficiency and moreus technology is advanced. For example, in Japan, the specific energy of batteries in the 1990s reached more than 150.
Generally, the specific energy is not printed on lithium-ion batteries, only the capacity is printed, and the maximum number of watt hours is printed!
The performance parameters of the battery mainly include electromotive force, capacity, specific energy and resistance. Using the battery as a power source, you can achieve power with stable voltage, stable current, stable power supply for a long time and little influence from the outside world. The battery structure is simple, easy to carry and charge. and the discharge operation is simple and easy. It is not affected by external climate and temperature, stable and reliable performance, developed in all aspects of modern social life.It plays a great role.
Detailed information
Battery knowledge
1. Normal charging
Different batteries have their own characteristics. Charging should be carried out in accordance with the manufacturer's instructions. In sleep mode, the phone also consumes battery. If you want to charge quickly, you must first turn off the phone or remove the battery to charge it.
2. Fast Charging
When the light signal on some automated smart fast chargers changes, it only indicates that the battery is 90% full and the charger automatically switches to slow mode. charging The battery is fully charged. It is best for users to fully charge the battery before use, otherwise the use time will be shortened.
3. Memory effect
If the battery is a nickel-cadmium battery, if it is not fully charged and discharged for a long timee, it will leave traces in the battery and reduce the battery capacity. This phenomenon is called battery memory effect.
4. Eliminate memory
The method involves completely discharging the battery and then recharging it. For discharge, you can use a charger or charger with a discharge function, or you can use the sleep mode of the mobile phone. If you want to speed up the discharge, you can turn on the lights on the phone's display screen and buttons. To ensure that the battery can be recharged, follow the instructions in the instruction manual to check the time and repeat charging and discharging two to three times.
5. Battery storage
Lithium batteries can be stored in a clean, dry, ventilated room with an ambient temperature of -5°C to 35°C and a relative humidity of no more than 75%. Avoid contact with corrosive substances and keepaway from fire and heat sources. The battery power remains between 30 and 50% of the nominal capacity. It is recommended to recharge stored batteries every 6 months.