What is Series and Parallel Connection?

Connecting two (or more) batteries together in series or parallel is done differently. For example, to connect LiPo batteries in series, the positive terminal of each must be connected to the negative terminal of the next battery. When connecting lithium batteries in parallel, all positive terminals should be joined together and all negative terminals linked. This process needs to be repeated until all batteries have been connected.

Why do You Need to Connect the Batteries in Series or Parallel?

In order to maximize the effectiveness of our solar lithium batteries, we need to use these two connection methods to achieve the best effect. So what kind of effects can we achieve with parallel and series connections? Series and parallel lithium solar batteries differ in their output voltage and capacity, which is the main difference between the two.
Connecting lithium solar batteries in series can help you to power machines that require greater voltages. For example, joining two 24V 100Ah models produces a 48V battery with the same 100 amp hours (Ah) capacity. It is important, however, that when connecting batteries in series they have the same voltage and capacity – for instance, 12V 100Ah and 24V 200Ah cannot be paired. Before linking your lithium solar batteries in series, please check that such a connection is possible for the product in question! If it is not, contact our product manager for further advice.
Lithium Solar Batteries are Connected in Series as Follows
In most cases, lithium solar batteries are connected in series so that the same current flows through all batteries, so that any number of batteries are connected in series. As a result, the total voltage is the sum of the partial voltages.
Connecting lithium batteries in a parallel configuration increases their ampere-hour capacity at the same voltage. For instance, connecting two 48V 100Ah solar batteries in parallel will yield a li ion battery with a capacity of 200Ah and the same 48V voltage. The same can be done with LiFePO4 batteries, using fewer wires as lower voltage, higher capacity batteries are employed. Parallel connections are not meant to increase output voltage but rather the duration for which the batteries can power your devices.
Instead of connecting lithium solar batteries in series, they can be combined in parallel configuration to boost the ampere-hour capacity while maintaining the same voltage. For instance, connecting two 48V 100Ah solar batteries in parallel would result in a li ion solar battery with a capacity of 200Ah, and a voltage of still 48V. Similarly when using LiFePO4 solar batteries, fewer parallel wiring is required by using lower voltage but higher capacity batteries. Although this arrangement does not increase output voltage beyond standard levels, it enhances battery performance by increasing duration time for powering devices.

This is How Lithium Solar Batteries are Connected Together in Parallel

When connecting solar lithium batteries in parallel, ensure that their positive terminals are linked and their negative terminals joined. In such cases, the total charge capacity (Ah) of all cells is added up but the voltage remains at the same level as each individual battery. As a principle, these cells should be of equal voltage and energy density with matching states of charge and have wires of the same cross-section and length.

What are the benefits of connecting solar lithium batteries in series?

A series circuit is easy to understand and build, and its basic properties make it simple to maintain and repair it. Due to this simplicity, it is also easy to predict the circuit’s behavior and calculate its expected current and voltage.
Also, series-connected batteries are often the better choice for applications requiring high voltages, such as three-phase solar systems in homes or commercial and industrial energy storage. The overall voltage of the battery pack increases when multiple batteries are connected in series, allowing it to provide the voltage required for the application. This can reduce the number of batteries needed and simplify the design of the system.
Furthermore, series-connected lithium solar batteries provide higher system voltages and lower system currents. By distributing the voltage over the batteries in a series circuit, the current flowing through each battery is reduced. With lower system currents, there is less power loss due to resistance, which results in a more efficient system.
The fourth reason why circuits in series are useful near flammable sources is that they don’t overheat as quickly. In a series circuit, the voltage is distributed amongst the batteries, resulting in lower currents for each battery than if it were applied to a single battery. Overheating is reduced as a result of less heat generated.
Lastly, higher voltages result in lower system currents, so thinner wiring can be used. Also, the voltage drop will be smaller, which means that the voltage at load will be closer to the battery’s nominal voltage. As a result, the system will be more efficient and expensive wiring will be reduced.
Lastly, in a series circuit, current must flow through all components of the circuit. This results in all components carrying the same amount of current. As a result, each battery in the series circuit receives the same amount of current, resulting in a balanced charge between them and an overall performance improvement.

What are the Disadvantages of Connecting Batteries in Series?

When it comes to a series circuit, if one point fails, the entire circuit is rendered unusable. This is because there can only be one path for the current to flow through, and any break in this will impede its progress. For those using solar power storage systems, such as lithium batteries, a battery management system (BMS) should be used to isolate any failed batteries before they have an effect on the rest of the pack.
When the amount of components in a circuit grows, the resistance of the circuit rises accordingly. In a series network, the total impedance is equal to the sum of each component’s resistance. With increasing components, this resistance will increase and can impair efficiency as well as bring about more power losses due to its presence. To lessen this, utilizing components with a lower impedance or swapping the series for a parallel configuration should be considered in order to minimize overall impedance.
Thirdly, series connection increases the voltage of the battery, and without an appropriate converter, it may not be possible to get the desired level of voltage from the battery pack. For instance, if two battery packs with 24V each are jointed in series, then the combined voltage will be 48V. Without a converter or a voltage regulator attached to this pack, it can harm any device connected to this as the voltage supplied is too high. To ensure safety, one must add a suitable converter or regulator which can adjust and provide the correct amount of power.

What are the Benefits of Connecting Batteries in Parallel?

The main advantage of connecting lithium solar battery banks in parallel is that it increases the capacity while keeping the voltage steady. This leads to an extended run time, with each additional battery connected doubling the capacity; this can be especially useful in applications that require a longer duration. For instance, two 100Ah lithium batteries will produce a capacity of 200Ah when connected in parallel, effectively doubling the amount of power available.
In a parallel connection, the failure of one lithium solar battery does not affect the current flow of the others. Thus, applications requiring a high level of dependability can still be powered as each has its own path through which to transmit electricity. This ensures that they can maintain the same voltage and capacity, regardless of any single battery malfunctioning.

What are the Disadvantages of Connecting Lithium Solar Batteries in Parallel?

If multiple batteries are connected in parallel, the total capacity of the lithium solar battery bank is increased, which increases the charging time. The charging time may also become longer and more difficult to manage if multiple batteries are connected.
Parallel connection of solar lithium batteries can result in a higher current consumption and a higher voltage drop, resulting in reduced efficiency and even overheating of the batteries.
Paralleling solar lithium batteries can be challenging when powering larger power programs or when using generators, as they may not be able to handle the high currents produced.
Using lithium solar batteries in parallel can make it harder to detect wiring or battery problems, which can result in reduced performance or even safety hazards.

Is it Possible to Connect Lithium Solar Batteries both in Series and in Parallel?

If multiple batteries are connected in parallel, the total capacity of the lithium solar battery bank is increased, which increases the charging time. The charging time may also become longer and more difficult to manage if multiple batteries are connected.
With a series-parallel connection, you group two or more batteries in parallel, and then connect multiple groups in series, increasing the capacity and voltage of your battery pack while maintaining safety and reliability.
In the case of four lithium batteries with a capacity of 50Ah and a nominal voltage of 24V, two batteries could be stacked in parallel to create a 100Ah, 24V battery pack. With the other two batteries, you can make a second 100Ah, 24V battery pack, and connect them in series to make a 100Ah, 48V battery pack.
Series and Parallel Connection of Lithium Solar Battery
With standard batteries, it is possible to achieve a certain voltage and power by combining a series connection and a parallel connection. Parallel connections provide the needed total capacity and series connections provide the higher operating voltage of the battery storage system.
Example: 4 batteries with 24 volts and 50 Ah each result in 48 volts and 100 Ah in a series-parallel connection.

Best Practices for Series and Parallel Connection of Lithium Solar Batteries

With standard batteries, it is possible to achieve a certain voltage and power by combining a series connection and a parallel connection. Parallel connections provide the needed total capacity and series connections provide the higher operating voltage of the battery storage system.
● Batteries of the same capacity and voltage should be used.
● Batteries from the same manufacturer and batch should be used.
● In the case of four lithium batteries with a capacity of 50Ah and a nominal voltage of 24V, two batteries could be stacked in parallel to create a 100Ah, 24V battery pack. With the other two batteries, you can make a second 100Ah, 24V battery pack, and connect them in series to make a 100Ah, 48V battery pack.
● A fuse or circuit breaker should be used to protect the battery pack from overcurrent or overvoltage.
● Batteries of the same capacity and voltage should be used.
● Batteries from the same manufacturer and batch should be used.