The average voltage of a lead-acid battery is 2V, and the average voltage of a single lithium battery is 3.7V. Due to different materials, the activity of lead-acid batteries is not not as high as that of lithium batteries. So the capacity of lithium batteries in the same volume is higher than that of lead-acid batteries. The battery is large (lead acid batteries are bulky). The lithium battery platform is not as stable as that of lead acid batteries.
1. Environmental protection, lithium batteries have no (non-absolute) pollution, while lead-acid batteries are polluted by heavy metal lead
2. Safety, power supply of lithium batteries (lithium manganate). , lithium iron phosphate), the safety of different materials is different. Lead-acid battery technology is quite mature and is safer than lithium batteries.
3. The specific energyue, the mass ratio and specific volume capacity of lithium batteries are approximately 40% higher than those of lead-acid batteries.
4. In terms of price, the price of a lithium battery of the same capacity is more than twice that of a lead-acid battery
5. Common lithium iron phosphate can be charged 1,500 times. There is no memory effect and the storage capacity is about 85% after 1500 times charging, while the lead-acid battery is about 500 times and the memory effect is obvious. >
6. Self-discharge rate, monthly self-discharge of lithium batteries is <3% for lead-acid batteries, the difference is obvious
7. In other words, for batteries of the same capacity, under high current discharge, lithium batteries will discharge about 30% more than lead acid batteries
8, the platform of voltage, lithium battery voltage platform is >3V, lead. -The batacid rie is 2V. If the capacity is the same, the same electrical appliances are used, the duration of use is the same. It's just that lithium batteries have a longer lifespan.
First, a correction, Ampere should be Ampere-hour, and the units of current and capacity must be distinguished. To understand how many batteries are needed to assemble a battery, you need to know the parameters of a single battery, one is the rated voltage and the other is the rated capacity. Whether it is an 18650 battery or other types of lithium batteries, they will have a nominal voltage, but the capacity will be different.
How many 18650 lithium batteries are needed to assemble a 12V20Ah battery?18650 refers to the size of the battery. It is a cylindrical lithium battery with a diameter of 18mm and a length of 65mm. the cell is generally 3.7 V and the saturation voltage ist of 4.2V, commonly used cell capacities are 2000mAh, 2200mAh, 2600mAh, etc. The current largest cell capacity can be around 3400 mAh. As the cell capacity increases, the cost will also increase. Once you know the battery cell parameters, you can perform calculations based on the required parameters. The first is the nominal voltage. Since the full charge voltage of a single cell is 4.2 V, a voltage of 12 V requires three batteries to be connected in series and the resulting nominal voltage is 12.6 V.
The next step is to calculate the capacity. Since there are many simple battery capacity specifications, based on the calculation of 2000 mAh, 20 Ah requires 10 batteries, and the required capacity can be obtained by connecting them in parallel. . So the final battery is a 10 parallel, 3 string battery, which requiresa total of 30 cells.18650 battery.
What other accessories are needed to assemble the battery?After calculating the number of cells in the battery and the connection method, you need to connect these batteries. Lithium battery connections are usually spot welded through nickel strips and cannot be connected by conventional soldering. Use a soldering iron to solder because the battery dissipates heat quickly, and when it reaches the solder melting temperature, the temperature rise of the battery will be relatively high, which is prone to problems. Additionally, if a flux is used, residuals will also be present. be corrosive to some extent. In addition, in order to ensure the stability of the battery, you can use standard battery fixing bracket to fix it and then weld it, or you can directly ask the seller to assemble the battery whenpurchasing the battery.
After completing the basic battery connection, you still need to connect the protection board. The main function of the protection board is to protect the lithium battery and cut off the output in case of overcharge, overdischarge, overcharge and short circuit. Battery protection can also protect part of the charging circuit. Since it is a 12V three-string lithium battery, you need to choose a protection board for the three strings. You should also select the protection current according to the load power, which is generally twice the rated current.
The assembled batteries are packaged in Highland barley paper and heat shrink film to obtain the final battery. When lithium batteries are assembled into battery packs, parameters such as voltage, capacity and internal resistance muststay as consistent as possible. If these parameters differ significantly, the gap will become larger and larger during use. Over time, batteries with inconsistent settings within the battery pack may become damaged prematurely.