# What Should I Do If The Lead-acid Battery Is Not Used For A Long Time? How To Repair Lead-acid Batteries?

- Dec 21, 2019-

The purpose of paralleling lithium batteries is to increase capacity. Therefore, parallel charging of lithium batteries also has different design characteristics compared to single-cell lithium batteries, which is mainly reflected in the consistency of the charging current design and parallel batteries.

The characteristics of parallel lithium batteries are: constant voltage, battery capacity added, internal resistance reduced, and power supply time extended. The core content of parallel charging is the magnitude of the parallel current and its role. According to the parallel theory, the main current is equal to the sum of the currents of the branches. Therefore, n parallel lithium batteries that have been combined into a battery pack must achieve the same charging efficiency as a single battery. The charging current should be the sum of the currents of n lithium batteries. Under the formula of Ohm's Law: I = U / R, this design is reasonable. However, the internal resistance of the battery after the parallel connection will also change. According to the parallel internal resistance formula, the total internal resistance of two parallel lithium batteries is equal to the ratio of the product of the internal resistance of the two batteries and the sum of their internal resistances. The number of parallel batteries increases and decreases. Therefore, the efficiency of parallel charging of lithium batteries can be achieved on the basis that the current is less than the sum of the currents of n parallel lithium batteries.

Lithium batteries connected in parallel should pay attention to the consistency of the battery, because the parallel lithium batteries with poor consistency will not be charged or overcharged during the charging process, which will damage the battery structure and affect the life of the entire battery. Therefore, when using parallel batteries, lithium batteries of different brands, different capacities, and different levels of old and new should be avoided. The inherent requirements for battery consistency are: lithium battery cell voltage difference ≤10mV, internal resistance difference ≤5mΩ, capacity difference ≤20mA.

In fact, after the lithium batteries are connected in parallel, there will be a charge protection chip to protect the lithium batteries. Lithium battery manufacturers have fully considered the characteristics of the changes after the lithium batteries are connected in parallel when making the lithium batteries in parallel. The battery cell is selected, so the user needs to charge the battery step by step according to the instructions of the parallel lithium battery to avoid possible damage to the battery caused by incorrect charging.

The battery series voltage is equal to the sum of the battery voltages in the string. Increase the voltage. The bulbs are connected in series. One switch can control all the bulbs connected in series on one line.

Using the cells in series can increase the output voltage. What are the characteristics of the bulbs in series: the sum of the voltage of each bulb is the total voltage of the circuit

After the batteries are connected in series, the voltages are added and the currents are equal, which increases the voltage; the batteries are connected in parallel and the voltage is unchanged (provided that the batteries with the same voltage can be connected in parallel, otherwise the high voltage will charge the voltage too low, if the difference is too large There is also danger), the current is equal to the sum of the batteries, which can often be considered as increasing the battery capacity and providing a larger current.

As the voltage increases, the capacity does not change.

The difference between batteries in series and parallel:

Battery in series:

The battery is connected end to end. That is, the anode of the first battery is connected to the anode of the second battery, the anode of the second battery is connected to the anode of the third battery, and so on;

The series voltage is equal to the sum of the battery voltages, and the current is equal to the current flowing through each battery;

Damage to one of the battery packs will cause the entire battery pack to become unusable or the voltage dropped;

Series connection can boost the total voltage.

Battery in parallel:

Refers to the battery head-to-tail connection. That is, the positive poles of all batteries are connected, and the negative poles of all batteries are connected.

The parallel voltage is equal to the single battery voltage, and the current is equal to the sum of the battery currents.

Although the battery life is enhanced, the damage caused by short-circuit current is more serious;

Paralleling can increase the total current.

1. When the batteries are connected in parallel, the voltage is equal everywhere, that is, Ua = Ub = Uc = Uo; the current is the sum of the currents of the various batteries, that is, Io = Ia + Ib + Ic. (See Figure 1 Battery Parallel Circuit)

Battery parallel connection is suitable for the situation where the voltage is constant and the current needs to be increased.

2. When the batteries are connected in series, the current is equal everywhere, that is, Io = Ia = Ib = Ic; the voltage is the sum of the voltage of each battery, that is, Uo = Ua + Ub + Uc. (See Figure 2 series circuit of the battery)

The use of batteries in series is suitable for situations where the current is constant and the voltage needs to be increased.

Whether in series or in parallel, the output power of the battery pack increases.

Parallel: Several batteries, positive and positive, negative and negative are connected side by side, the voltage is unchanged, the capacity is increased, and the corresponding current is also increased. Series: Several batteries are connected in series, that is, positive and negative, the negative of the first section is connected to the positive of the second section, and so on. As the voltage increases, the capacity does not change. In other words, if connected in series, the electromotive force is the sum of the electromotive forces of the two batteries. If they are connected in parallel, the voltage they provide to the consumer is as large as the electromotive force of one battery. Hope my answer can help you! I am also learning this part, it is difficult,

When connected in series, the voltage is the sum of the two battery voltages. When connected in parallel, the voltage is equal to the voltage of the two batteries

Increase the voltage in series and increase the capacity in parallel. For example, if you have two 1.5 volt, 2000 mAh batteries, you will get a 3 volt, 2,000 mAh battery in series, and a 1.5 volt, 4,000 mAh battery in parallel.

1. When the batteries are connected in parallel, the voltage is equal everywhere, that is, Ua = Ub = Uc = Uo; the current is the sum of the currents of the various batteries, that is, Io = Ia + Ib + Ic. (See Figure 1 Battery Parallel Circuit)

Battery parallel connection is suitable for the situation where the voltage is constant and the current needs to be increased.

2. When the batteries are connected in series, the current is equal everywhere, that is, Io = Ia = Ib = Ic; the voltage is the sum of the voltage of each battery, that is, Uo = Ua + Ub + Uc. (See Figure 2 series circuit of the battery)

The use of batteries in series is suitable for situations where the current is constant and the voltage needs to be increased.

Whether in series or in parallel, the output power of the battery pack increases.

1. In series, the current is constant and the voltage is added; in parallel, the voltage is constant and the current is added

2. Although the voltage has not changed, two 12v batteries are connected in series to obtain a higher voltage to adapt to electrical appliances. A current of 10A above 100w is required, such as an inverter with a design value of 12v input. This is important for switches and wires. The requirements are extremely high, so reducing the current is the main reason. Two parallels are required, but the normal discharge current allowed is doubled. If 24v is used, the current is only 5A. Therefore, many places use high-voltage electrical appliances (such as electric vehicles) is the reason. But some appliances are 12v. When their power (current) is large, in order to increase the working time of the battery or the current of a single battery is not enough to drive, the battery is only 12v, and some consumers have a larger power.