How To Connect Two 12-Volt Batteries To Make 12 Volts?

Key Points:

  • To connect two 12 volt batteries to make overall 12 volts, you need to connect them in parallel.
  • Connect the positive terminals together and the negative terminals together of both the batteries. The negative terminals will be grounded and positive will be attached to the load
  • Connecting two 12-volt batteries will make 12 volts overall, while the overall capacity will be doubled. 

Sometimes we need to connect two or multiple batteries together for a single application. Batteries are either connected in series or in parallel to improve their overall voltage or capacity respectively. So, how to connect two 12 volt batteries to make 12 volts?

Well, when two batteries are connected in a parallel connection, the voltage stays the same, while the amperage of both batteries is added together. In order to achieve 12-volt from adding up two 12 volt batteries, you have no other thing to do except connect them in parallel.

This article will discuss in detail how can you connect two 12-volt batteries to make a 12 volt battery bank. So, let’s get started!

How to Wire Two 12 Volt Batteries Together?

Many appliances including cars, trucks, and RVs run 12-volt batteries for various reasons. As the batteries provide more overall voltage or capacity depending upon the type of connection they have, you may get 12 volts or 24 volts from connecting two 12-volt batteries.

If you connect the 12 volts batteries in parallel, the amp output will be the sum of the total batteries that are connected this way. For example, if two 250-amp batteries are connected in parallel, the total amperage will be equal to 500 amperes. On the other hand, the voltage will be just the same which will be 12 volts.

To connect two 12 volts batteries in parallel, you need to attach the positive terminals that are denoted as a positive (+) sign together. Then, connect the negative terminals together that are marked with the negative (-) sign. If you see the figure, the positive terminals are illustrated with the red color and the negative terminals are with black color.

Connect the terminals as shown in the figure. Then, attach the positive terminals to the charging unit, popularly known as the load. On the other side, negative terminals are attached to the ground to complete the circuit.

Things to Remember While Installing a Second Battery:

Now, there are some important things to remember every time you are going to attach two or multiple batteries together. Always use identical batteries and ensure the same make as well as AH rating if possible.

Before starting with the connection, take a little time to charge them up fully so that both of them have an identical charge level. Therefore, no charge will move from a highly charged battery to the lower charged battery to balance the connection. 

Again, use two batteries of the same date and preferably a new one. Also, take a look at the connecting cables to get the maximum from the batteries. Try to arrange cables of the same length which will stop the chance of the difference in electrical loss.

It is also important to remember not to connect both the battery’s negative terminals to the chassis of the vehicle. At first, put a link between the two terminals and then only one to the chassis or the body of the vehicle.

Sometimes, people mistakenly connect the positive and negative terminals of the same battery together. This eventually causes a short circuit and damages the battery. So, take time to plan and arrange everything in order before committing anything worse.

Frequently Asked Questions (FAQs):

Can I Connect 2 12-Volt Batteries Together?

Yes, you can certainly connect two or more 12-volt batteries together whether in a series connection or a parallel connection.

Do Batteries In Parallel Last Longer?

Batteries connected in a parallel connection seem to last longer. This occurs as the voltage remains the same. If you connect two 12 volt batteries in parallel, their amperage will be doubled but the voltage will be 12v as before. So, the batteries will last longer.

How Many 12v Batteries Can I Connect In Parallel?

Well, there is no such theoretical restriction to the number of batteries that can be connected in parallel. However, the more batteries you’re working with, the more complex the connection will be which will increase the chance of any sort of damage. So, it is better not to connect too many batteries.

Final Words

There may always lot of confusion that comes up while connecting batteries either in series or parallel connection. Having a complete understanding and planning will keep you and the batteries safe from all sorts of damage.

This article discussed the detailed process regarding two 12 volt batteries to make 12 volts while the overall capacity doubles. Hope you liked the article. In case of any queries, the comment section will be wide open. You may also be interested to read how to connect 4 12V batteries to make 48V.

Thanks for reading.

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