How to distinguish the power of the battery

A battery that reaches twelve volts but less than 20 ah may not be able to drive.

20ah is the capacity of the battery, not the power. When the current is constant, the larger the capacity, the longer the power can be used.

20ah means that when the battery output current is 20 amps, it can be used for 1 hour. It can also be understood that when the battery output current is 2 amps, 10 hours can be used. That is, the product of current and time is 20.

When the device requires a 20ah high-power battery to drive, the device has a large operating current, and a small-capacity battery may not be able to withstand this large current. If the small capacity battery can withstand the device drive current, it can be driven. Just as you have a dozen batteries connected in series to drive an electric bicycle, it can't be driven.

First of all, the shape of the 18650 battery is cylindrical, and there is liquid inside. Because of the design of the battery and the characteristics of the raw materials, the power type 18650 battery is suitable for large current discharge, so almost all high-power products on the market use 18650 lithium batteries, but ultra-thin notebooks, especially It is a tablet computer, etc., because it requires a thinner appearance, so instead of using a 18650 battery, it uses a polymer lithium battery , but a high-power digital camera is different, because the charge and discharge of the flash requires a large voltage and a large current, so it can only With the 18650 power lithium battery or other models of power batteries, but the volume is slightly smaller, such as 18500 power lithium battery is commonly used in digital camera products; and with the 18650 power lithium battery high energy density and high current discharge advantages, so just now

Electric cars are designed with 18650 lithium battery.

The advantages of polymer lithium battery, small size, large capacity, the shortcoming is that the life is shorter than 18650, because different designs and materials are used, some have liquid inside, some are dry or colloidal, and the performance is not as good as 18650 when discharging at high current. Cylindrical batteries, so the need for large-capacity and small-volume electrical equipment, usually using polymer lithium batteries, the most typical performance is mobile phones, tablets and other equipment.

The rechargeable battery is a rechargeable battery with a limited number of times of charging, and is used with a charger. The market generally sells No. 5 and No. 7, but also has No. 1. The advantages of rechargeable batteries are economical, environmentally friendly, and sufficient power, suitable for high-power, long-term use of electrical appliances (such as Walkman, electric toys, etc.). The voltage of the rechargeable battery is lower than that of the same type of disposable battery. The AA battery (charge No. 5) is 1.2 volts, and the 9V rechargeable battery is actually 8.4 volts. Now the average number of times of charging can be around 1000 times. As of February 2012, there are only five types: nickel cadmium, nickel hydride, lithium ion, lead storage, and iron lithium.

The active material on the positive electrode of lead-acid battery is lead dioxide, the active material on the plate is spongy pure lead, the electrolyte is a certain concentration of sulfuric acid solution, and the electromotive force between the plates is about 2V.

The active material on the positive electrode plate of the nickel-cadmium battery is nickel oxide powder, and the active material on the negative electrode plate is cadmium oxide powder. The active materials are respectively wrapped in the perforated steel strip, and become the positive and negative plates of the battery after press molding. The electrolyte is usually treated with potassium hydroxide solution. The open circuit voltage of the battery is 1.2V.

The material of the positive electrode plate of the nickel metal hydrogen battery is nickel oxide powder, the material of the negative electrode plate is a hydrogen absorbing alloy, and the electrolyte solution is potassium hydroxide solution. The open circuit voltage of the battery is 1.2V. The lithium ion battery uses LiCoO2 composite metal oxide to form an anode on the aluminum plate, the lithium carbon compound forms a cathode on the copper plate, and the submicron microporous polyolefin film separator between the plates. The electrolysis liquid is an organic solvent. The open circuit voltage is 3.6V.

Lithium polymer battery is an improved type of lithium ion battery. There is no battery liquid. Instead of polymer electrolyte, it is more stable than ion battery. The open circuit voltage is 3.6V.

The battery capacity represents how much battery the battery can store. The numbers we see on the battery pack generally refer to the battery capacity indicator. It is expressed in units of ampere-hours or milliamps. It is a composite unit consisting of the current unit and the time unit product, representing the ability of the battery to sustain discharge at a constant current. A fully charged battery can be discharged with a current of 200mA for 10 hours. By multiplying the current by time, we can get the capacity of this battery is 2000mA.H. If it is discharged at 400mA, the available time is 5 hours.

Energy density: The amount of electrical energy contained in a unit volume or unit weight. For the same power requirements, a battery with a high energy density can be smaller in size and lighter in weight.

C current: refers to the amount of current that is filled in a fully charged battery or filled with a used battery in one hour. In fact, it is the value of the capacity of the hour. Battery with 1800mA capacity, C current is 1800mA. The battery of 2000mA capacity, the C current is 2000mA.

Open circuit voltage: refers to the potential difference between the two poles of the battery.

Memory effect: The new battery, whose electrode material has fine crystal grains, can obtain the largest electrode surface area. Because of the use, the battery content is crystallized. After crystallization, the crystal grains increase, also called (passivation), which reduces the available electrode area, and the grown crystal grains cause self-discharge to increase, so that the battery reduced capacity and impaired performance. This is the memory effect. The reason for the memory effect is due to incomplete partial charging and discharging of the battery.

Self-discharge rate: The battery after charging will gradually lose its power even when it is not used. Generally, the higher the temperature, the more significant the self-discharge is.

Nickel cadmium (Ni-Cd)

Voltage: 1.2V service life: 500 times

The discharge temperature is: -20 degrees to 60 degrees

Charging temperature is: 0 degrees to 45 degrees

Nickel hydrogen (Ni-MH)

Rechargeable Battery

Voltage: 1.2V

Service life: 1000 times

The discharge temperature is: -10 degrees to 45 degrees

Charging temperature: 10 degrees to 45 degrees

Remarks: At present, the maximum capacity of domestic No. 5 battery is about 3000mAh.

Lithium-ion (Li-ion)

Rechargeable Battery

Voltage: 3.6V

Service life: 500 times

The discharge temperature is: -20 degrees to 60 degrees

Charging temperature is: 0 degrees to 45 degrees

Remarks: The weight is 30% to 40% lighter than that of NiMH batteries, and the capacity is higher than that of NiMH batteries by more than 60%. However, it is not resistant to overcharging. If overcharged, the temperature will be too high and the structure will be destroyed.

Lithium polymer

Voltage: 3.7V

Service life: 500 discharge temperatures: -20 degrees to 60 degrees

Charging temperature is: 0 degrees to 45 degrees

Remarks: The improved version of lithium battery, without battery liquid, can be made into various shapes instead of polymer electrolyte, which is more stable than lithium battery.

Lead-acid batteries

Voltage: 12V

Service life: 200 to 300 times

The discharge temperature is: 0 degrees to 45 degrees

Charging temperature is: 0 degrees to 45 degrees

Remarks: It is a general car battery (it is 6V in series with 12V). The battery life of the water-free battery is up to 10 years, but the volume and capacity are the largest.

Feature editing

Nickel-cadmium: small memory effect capacity

Nickel hydrogen: memory effect, small capacity

Lithium ion: no memory effect, thin body and large capacity, due to different electrode materials, the electromotive force is 3.6v, 3.7v two. The performance of lithium battery is one of the best existing battery, small size, light weight, large capacity. Widely used in digital cameras, laptops, mobile phones and other electronic products.

Lead storage: The electromotive force is about 12V. The lead storage battery can be used repeatedly. The electrolyte is a sulfuric acid solution with a small internal resistance and is widely used in automobiles and motorcycles.

Iron Lithium: The power is more sufficient, safer and lighter, and the main development direction of electric vehicles in the future.

Generally, the same type of rechargeable battery has a larger capacity, a larger volume and a larger weight.

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