If you want to purchase batteries, you have probably already done some research. While doing so, you have probably encountered terms like series or parallel. While these are simple words, their meaning is complex.
Summary
The biggest difference between wiring batteries in series and parallel is the output voltage of your setup. To minimize the potential danger of wiring batteries in parallel, you want to make sure voltage is distributed evenly across the batteries. To wire in series, each battery is connected to the next, whereas parallel battery wiring isn’t.
In this article, we’ll go more in-depth with the following:
- How to do it right
- How are amps affected?
Continue reading
Some people ask about the difference between series and parallel. Although they know what these words mean, they don’t know how they apply to the wiring.
These terms can confuse you if you are new to lithium batteries or even batteries in general. We are here to help you and teach you about the dangers of wiring batteries in series vs. parallel, and also show you how to do it.
Your battery bank is one of the most important aspects. When two or more are connected for a single application, it results in a battery bank.
If you increase it with more batteries, the voltage capacity also increases and allows you to generate more power. This connection is made through wiring, which is done in a parallel or series connection.
When you have multiple battery systems, it is essential to understand the difference between parallel wiring and series wiring. The performance and output of these will be determined by how you connect them.
See below the differences between series wiring and parallel wiring in batteries. We will explain both of them, and you will be able to see how they perform and how efficient they are.
Table of Contents
Dangers of connecting batteries in parallel
Connecting batteries in parallel are not dangerous, and the risks are minimal. However, you should ensure that the voltage is distributed equally by both of your batteries. Both of them have the same life expectancy.
It also depends on the way you use them. When you connect them in a parallel circuit, the voltage is equal, but the current increases. For some devices, this can be beneficial. For those that are sensitive without a protection circuit, it can be very dangerous for them.
There are 3 different dangers in connecting batteries in parallel:
- Risk of explosion if the battery voltages are different
- Primary batteries may leak or bulge
- The lower voltage battery is more likely to overheat
For the health of your batteries, it is important to consider some aspects. Find information about their chemical construction and voltage, and capacity.
When you connect them in parallel, all of these specifications must be the same to provide the circuit with power efficiently.
If you ignore these factors, working with such a system can be dangerous. You are exposed to the risk of injury and damaging your batteries and electronic devices. That is why the voltage and capacity of your batteries have to be the same.
In the system, the better battery will charge the bad one. They will significantly affect their lifespan with this infinite loop of constantly charging and discharging themselves. In some extreme cases, this can generate a lot of heat and even start a fire.
Series connections
These connections involve two or more connected batteries to increase the system’s voltage. While the voltage is increased, the amp-hour rating is stable and unchanged.
In the case of series connections, having all your batteries feature the same voltage and capacity rating is critical. If they are different from each other, you risk damaging them.
To connect your batteries in series, a positive terminal of one must be connected to the negative one. This way, the desired voltage can be achieved. Remember that you have to use chargers that match the system’s voltage.
We also recommend using a multi-bank charger. It will allow you to charge each battery individually and also avoid an imbalance between them. Explore the advantages and disadvantages of a series connection below.
| Advantages | Disadvantages |
| Provides a higher system voltage | You can’t get lower voltages without a converter |
| Simple to understand and build | The entire circuit will fall if one point in a series fails |
| All components carry the same current | The circuit’s resistance grows as the number of components increases |
Connecting batteries in series is ideal for larger applications that require high voltage output. Because the voltage is higher, you can use thinner wiring for a lower system current. Voltage drops will also be reduced significantly.
A disadvantage of series connection is the lack of flexibility. All of your applications are required to work at a higher voltage.
If you connect two 12V batteries, you will get a system that produces 24V. Your 12V appliances cannot be supplied with power until you use a specific converter.
Parallel
In a parallel connection system, two or more batteries are connected. It’s done to increase the amp-hour capacity. It’s done while keeping the voltage at the same level. Positive terminals are connected through a cable. The same is done with negative terminals.
You cannot power up anything above the standard voltage output with such a system. However, you can increase the time your equipment can be powered.
When connecting your batteries in a parallel connection, an increased amp-hour capacity might require a longer charging time. Take a look at the advantages and disadvantages of a parallel connection.
| Advantages | Disadvantages |
| If one of the batteries fail, the other ones can still sustain the power | It needs a large number of wires |
| Extended runtime with constant voltage | The voltage level will be lower and the current draw will increase |
The main advantage of this connection is the increased capacity and longer applications of your system. If one malfunction, it won’t affect the others as they will continue to power up your appliances.
The only inconvenience of a parallel system is a longer charge time. Voltage drops can also occur as the lower voltage means a higher current draw. Thick cables are also needed. Sometimes it can be difficult to power large applications.
