Can I Charge Two 6V Batteries in Series?

Battery chargers can save you time and energy so you don't have to keep buying new batteries. Charging batteries in simple circuits with a charger and the batteries themselves can show you how the various properties of electricity differ throughout circuits. You can learn about charging 6 volt batteries in series with a 12 volt charger provided you follow these steps.

When dealing with the 6 volt (6V) batteries, make sure to take safety precautions. Don't mix different makes or powers of batteries with one another because the differences in their capacity can cause uneven or hazardous charging. Use rubber gloves if necessary, and avoid touching wires that aren't appropriately insulated. Pay attention to how hot circuit elements can be to prevent overheating.

Charging 6V Batteries in Series

To create an electrical circuit in series, make an electrical circuit that loops through each element one after another like they were metal chains linking together. In a series circuit, the flow of charge in the form of current remains constant throughout the circuit.

For two 6V batteries, you can connect the positive output wire (in red) of the charger that is 12 or more volts to the positive terminal of the first battery. Then, connect the negative end of the first battery to the positive end of the second one, and connect the negative end of the second battery to the negative output wire (in black) of the charger.

You can test the charge in the circuit using a multimeter or voltmeter. If you have one of these available, connect the positive terminal of the device to the positive terminal of one of the 6V batteries, and connect the device's negative terminal to the negative end of one of the batteries. Change the range of the multimeter or voltmeter to around 0 to 12 volts, and read the number it tells you. Five volts or less means you should recharge the battery.

At what voltage is a 6 volt battery dead? If the multimeter or voltmeter can't read any charge across it, it's dead. If you keep track of the voltage of your batteries, you can prevent this from happening. Otherwise it might be difficult to recharge the batteries back to how they once were.

Charging batteries in series increases the voltage across each battery. The voltages themselves should add together to equal the voltage of the battery pack source. For example, you can connect two 6V batteries in series with a 12V source to recharge them. This works because, in a series circuit, current has only one direction or path to take, and, as a result, it remains constant throughout the circuit while the voltage changes with each battery connected in series.

Charging Deep Cycle Batteries in Parallel

If you need a battery to create a power source over a long period of time, you may consider using a deep cycle battery. These types of batteries can run reliably until they're discharged at about 80% or more, and the term deep cycling refers to this method of recharging only after being discharged such a great amount.

Because they can go so long without needing to be recharged, they're very useful for applications that need to run for long periods of time without stopping. This makes them ideal for marine applications, recreational vehicles, materials handling and even renewable energy.

Connect deep cycle batteries in parallel with one another by connecting the positive end of one battery to the positive end of the other. Then, connect the negative end of one battery to the negative end of the other. Finally, pick one battery and connect its positive end to the positive output of the charger and its negative end to the negative output of the charger.


About the Author

S. Hussain Ather is a Master's student in Science Communications the University of California, Santa Cruz. After studying physics and philosophy as an undergraduate at Indiana University-Bloomington, he worked as a scientist at the National Institutes of Health for two years. He primarily performs research in and write about neuroscience and philosophy, however, his interests span ethics, policy, and other areas relevant to science.