The main difference between battery parallel connection and series connection is the difference in voltage and capacity. Take a 3.7V lithium battery with a capacity of 3000mAh, which is also two batteries. If it is two series, the model of the battery pack is 7.4V/3000mAh, and if it is two parallel, the model becomes 3.7V/6000mAh. When connected in series, the voltage will increase, but the capacity will remain unchanged, and when connected in parallel, the capacity will increase, but the voltage will remain unchanged. However, the batteries we often use are in parallel, series, such as three series and four parallel. I hope it can help you.
The parallel voltage of the battery remains unchanged, and the power supply current can be increased
The battery series connection can increase the power supply voltage, and the current will not
1. Dry batteries are widely used in life, and series and parallel are common connection methods.
2. Series connection: Connect the positive pole of the dry battery to the negative pole of the next battery, and then this is the series connection.
The advantage of series connection is that the voltage (V) of the power supply is doubled, which is generally used to drive electrical appliances with higher rated voltages.
3. Parallel connection: Generally, the voltage of the battery is the rated voltage of the relevant electrical appliances. The parallel connection of the battery is used for energy supply, which can increase the current at the rated voltage and better drive the electrical appliances while keeping the voltage unchanged.
4. Summary: According to the different needs of different electrical appliances, the use of parallel battery strings can achieve unexpected results
Under the same voltage, the use of parallel batteries will increase the use time, while the series connection of batteries will increase the battery voltage to match the voltage of the electrical appliance. If the voltage is low, the electrical appliance cannot start
Differences between series connection and parallel connection of dry batteries
1. When dry batteries are connected in series, since each dry battery has an electromotive force and internal resistance, the advantage of the dry battery after series connection is that it can provide a higher voltage; the disadvantage is that its internal resistance is large, which affects the power and current it provides.
2. After the dry battery, it is parallel connection, because parallel connection can reduce the internal resistance of the battery pack, it can provide greater current and power; the disadvantage is that the voltage it provides is only equivalent to the voltage of the dry battery.
3. Mixed connection of dry batteries: A battery group in which some dry batteries are connected in series and some batteries are connected in parallel is called mixed connection. This can solve the problem that cannot be solved by using only series connection and parallel connection. Several batteries, positive and positive, negative and negative, are connected in parallel, with a constant voltage, increased capacity and corresponding current. Series connection: Several batteries are connected together, that is, positive and negative, the negative pole of the first section is connected to the positive pole of the second section, and so on. When the voltage increases, the capacitance remains unchanged. That is, if connected in series, the electromotive force is the sum of the electromotive forces of the two batteries. If the parallel connection rises, the voltage they provide to the appliance is only as large as the electromotive force of one battery. I hope my answer can help you!
Considering the internal resistance of the battery, the output voltage is between the two.
For simplicity, let’s discuss two batteries first. The voltage output by the electromotive force E1 is U=E2-Ir2=(E1r2-E2r1)/(r1 r2) The main difference between parallel and series connection of batteries is the difference in voltage and capacity. Take a 3.7V lithium battery with a capacity of 3000mAh, also two batteries. If it is two series, the model of the battery pack is 7.4V/3000mAh, and if it is two in parallel, the model becomes 3.7V/6000mAh. When connected in series, the voltage will increase, but the capacity will remain unchanged, and when connected in parallel, the capacity will increase, but the voltage will remain unchanged. However, the batteries we often use are in parallel, series, such as three series and four parallel. I hope it can help you.
Precautions for lithium battery packs in parallel
Do not use batteries of different brands, voltages, capacities and materials together.
When the battery is low, please replace all batteries.
Use a lithium battery protection board with corresponding parameters.
Choose batteries with consistent performance. Generally, lithium battery series and parallel use require lithium battery pairing. Matching standard: voltage difference 10mV, internal resistance difference 5m, capacity difference 20mA
1. Series connection of lithium batteries with different voltages
Due to consistency issues, lithium batteries should be grouped in parallel under the same system (such as ternary or lithium iron), and the same voltage, internal resistance and capacity should be selected when grouping. The series use of batteries with different voltage platforms and internal resistances will cause one battery to be fully charged and discharged first in each cycle. If there is a protection board and no fault occurs, the capacity of the entire group will be reduced. Without a protection board, the battery will be damaged by overcharging or putting it in.
2. Parallel connection of lithium batteries with different capacities
If lithium batteries of different capacities or new and old ones are used together, leakage and zero voltage may occur. This is due to the difference in capacity during the charging process, which causes some batteries to be overcharged while others are not fully charged. When discharging, some batteries with large capacity are not fully discharged, while batteries with small capacity are over-discharged. In this vicious cycle, the battery is damaged and leaks or has a low voltage (zero).
