How to connect Batteries in Series vs Parallel | 5 important Q&A

If you know anything about batteries, you must have heard of batteries in series vs parallel, and series-parallel. But what do these concepts mean?

Batteries in series vs parallel and series-parallel are the ways of connecting batteries, and what are the advantages of connecting batteries together over using them individually? If you have the demand for increasing the voltage or amp-hour capacity, or even both; Connecting the batteries in series, series-parallel, or parallel, will certainly help you. These measures are allowed for power-hungry applications or higher voltage applications.

Next, we will share with you how to take series, parallel, and series-parallel measures for batteries. As well as the different uses and advantages of each method.

Series

When the batteries are connected in series, the voltage of the battery system increase, while the capacity remain the same. For instance, if we connect 2 batteries of 12V100Ah in series, we will get a battery system of 24V100Ah.

To connect batteries in series, you need to connect the positive terminal of one battery to the negative terminal of another battery. Measure the system’s total output voltage between the negative terminal of the first battery and the positive terminal of the last battery in series.

When charging batteries in series, a charger that matches the battery system voltage is needed. To avoid battery imbalance, charging each battery individually can also be a safer approach.

Please pay special attention that when configuring lithium batteries in series, the Battery Management System (BMS) or Protection Circuit Module (PCM) should be taken into account.

Parallel

When the batteries are connected in Parallel, the capacity of the battery system increase, while the voltage remains the same. For instance, if we connect 2 batteries of 12V100Ah in series, we will get a battery system of 12V200Ah.

To connect batteries in Parallel, you need to connect the positive terminals of all batteries together and all of the negative terminals together. Measure the system’s output voltage across any two positive and negative battery terminals in parallel.

Batteries that are configurated in parallel help increase the duration in which batteries can power equipment, but at the same time, the parallel battery system needs more time than series-connected batteries to be fully charged because of the increased capacity.

Series-Parallel

Except for the above, there is also another way to combine these two methods: Series-parallel. This kind of connection helps increase both the voltage and capacity of the battery system by connecting a string of batteries.

For instance, six 6V 100Ah batteries can be connected together to output a voltage of 12V and a capacity of 300Ah, this is achieved by configuring three strings of two batteries.

Batteries in Series vs Parallel Q&A

The batteries that are wiring in series or parallel should have the same voltage and rated capacity. Because wiring batteries in different voltages and capacities can cause problems that may damage the batteries. Please noted following batteries in series vs parallel Q&A.

How to Charge Batteries in Series or Parallel?

No matter whether the batteries are wired in series or parallel, batteries in series vs parallel, the first step of charging the batteries is to choose the correct voltage charger. Besides this, batteries in series vs parallel charge the same way: connect the positive charger cable to the positive terminal on the first battery and the negative charger cable to the negative terminal on the last battery.

How Many Batteries Can You Wire In Series?

For this question, you should always check with the manufacturer to ensure that their limit of batteries in series doesn’t be exceeded. In other words, how many batteries can be wired in series depends on the battery and manufacturer.

How Many Batteries Can You Wire In Parallel?

There is no limit to the battery quantity that you wire in parallel. The more batteries in the parallel circuit, the more capacity and longer runtime will be obtained. However, please remember that the more batteries are in the parallel system, the longer it will take to charge.

Using very large parallel battery packs also results in higher current availability. This means that the correct system fuses are critical to prevent accidental short circuits, it can be catastrophic with such a large amount of current available.

Can You Wire Batteries in Series and Parallel at one time?

The same batteries cannot be wired in series and parallel at one time because the system will be shorted, but you can wire battery sets in series and parallel to create a larger battery bank at a higher voltage.

Do Batteries Last Longer In Series Or Parallel?

Batteries in series vs parallel both provide almost the same amount of runtime.