What Happens When You Add More Batteries to a Series Circuit?

A circuit is an unbroken pathway for electric current to flow. This is what the simplest circuit looks like. It has a power source, two wires attached to both the battery terminals, and on the other end of the wires.

When you connect batteries in a series configuration, their terminals are connected in a sequence. This means that the positive terminal of the first battery is connected to the negative terminal of the second, and the positive of the second battery is connected to the negative of the third battery.

It is like a TV series where the batteries are placed one after the other. If you want to calculate the circuit’s voltage, you need to add the voltage of all the batteries that are in the circuit. Knowing all these, you might ask what would happen if you add more batteries to a series circuit? Please keep reading to find it out.

Adding More Batteries to a Series Circuit

Adding multiple batteries in a circuit increases the voltage of the batteries, but the total capacity of the circuit will be the same. Unlike batteries connected in a parallel configuration, batteries connected in a series configuration give an increased voltage output without changing the amperage of the circuit measured in amp-hours. For example, many batteries in a series circuit of electronic equipment are six volts. When you add another, say, a 6-volt battery to a circuit with two 6-volt batteries, it can produce 18 volts, but the amperage does not change.

How to Add Batteries to a Series Circuit

Here are the step-by-step process of adding batteries in series current:

Step 1: Get a set of jumper cables.

Step 2: Plug the first battery’s positive terminal into the second one’s negative terminal.

Step 3: Get another set of jumper cables.

Step 4: Attach the open terminals at either end of the batteries to the application you want to power. It means you’ll connect the free end of one wire with the negative terminal of the first battery and the free end of the second wire with the positive terminal of the second battery. 

Finally, you have a closed circuit with two batteries connected to an application with two jumper cables. You can add virtually any number of batteries, depending on the output voltage you seek.

Frequently Asked Questions

Does Adding Batteries in Series Increase Current?

No, it does not. When you connect a group of batteries in a series configuration, you increase the overall voltage of the circuit but not the current. The current’s unit is called ‘amperes,’ and it is measured using an ammeter. The current has to be the same across all batteries in a series circuit, so there is no risk of imbalances that might cause problems like a short circuit.

How Many Batteries Can You Put in Series?

There is no limit on the number of batteries you can add to a series circuit. Each battery you add counts to the overall output voltage of the circuit. This means you can virtually create an unending power system. But remember that you will need to charge these batteries at some point and will need a power system that can do the job.

You also need to put aside a solid chunk of time to charge them all to 100 percent. And when you increase the voltage of a circuit, you need to find a charger that can meet the output.

Theoretically, the only limit on the number of batteries is if you have connected so many of them that you start seeing sparks on one of the ends of the circuit.


You must remember that when connecting the circuit, the positive and negative open terminals must never cross each other. If they do, there will be a short circuit, and the batteries will get damaged. Also, you should think of ways to charge these batteries. When you get to that point, you must ensure that the battery voltage matches the voltage of the charger so there is no imbalanceresulting in the circuit not working.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.