# Connecting Batteries in Parallel to Extend Runtime!

If you need an extended period as a backup from a battery, you definitely have to connect multiple batteries in parallel. Connecting the batteries in a parallel connection increases the amp-hour. However, the voltage of each battery remains the same.

This article will share tips on connecting multiple batteries to get the highest operation time.

## How To Safely Connect Batteries in Parrel

As previously mentioned, connecting batteries in parallel improves their run time. But how do you connect the batteries?

It’s simple. The first thing you need to do is ensure you have batteries of the same voltage. For instance, if you choose 12v batteries, connect 12v batteries only. Don’t have any 6v or other voltage in the battery. If you connect batteries with different voltages, they won’t work.

For connecting two or multiple batteries, you need to connect them in parallel properly. This includes connecting the batteries in the right order. The thumb rule of a parallel connection is connecting the positive terminal with the positive and the negative with the negative terminal. You must connect the first positive terminal to the next positive terminal of the other battery. And connect the first battery’s negative terminal to the second one’s negative terminal.

If you are about to connect two or more batteries in parallel, their capacity or amp/hour will be improved while the voltage remains the same. If the batteries have the same voltage and amp/hour, the combined battery’s capacity will be doubled. For instance, if you combine two 6-volt batteries with a 10AH capacity in parallel, the combined one will give you the same 6-volt voltage with a doubled capacity which is 20AH in this case.

The battery with a higher voltage will try to charge the low-voltage battery to balance the circuit. But the disposable batteries are designed not to be recharged.

If the batteries are rechargeable, on the other hand, the battery with a low voltage will charge from the high-voltage battery to balance the circuit. If the batteries create a charge limit within the circuit, it may leak, swell, or overheat the battery bank.

Overheating can cause a rapid charge drain of the higher-voltage battery. Plus, overheating can easily lead to an explosion.

Also, if you connect two different-aged batteries in parallel, they will develop some issues. The older battery will have a lower voltage capacity as it decreases with time. It also takes more time to charge at the same speed as the new one.

That’s why it is important to use same-age batteries with the same capacity. Try to charge them fully before connecting in parallel. Otherwise, one will charge the other one providing you no benefit.

## Simplified Steps to Connect Batteries In Parallel

Once you collect your suitable batteries, now is time to connect them in parallel. Apart from the rechargeable batteries, you also need pairs of battery cables. Here’re the steps to follow to connect batteries in parallel to extend runtime.

### Step 1: Place the Batteries

Place the batteries closely side by side. The batteries shouldn’t have a long distance between them as it will require long cables.

Step 2: Connect the Positive Terminals

The red terminal indicates the positive terminal. Take the red battery cable to connect the positive (red) terminal of the first battery to the positive of the other battery.

### Step 3: Connect the Negative Terminals

Take the black negative battery cable and connect the first battery’s negative (black) terminal to the negative of another battery. You must never connect positive terminals to negative terminals, as that’ll short-circuit the overall connection.

### Step 4: Check the Connections

Once you are done with the connection, it is time to check whether you have put a connection through the same polarity or not. The first battery’s positive must be connected to the positive of the second one. It is applied to the negative terminals as well.

Correct any mistake you might have made by now.

Do Batteries Connected In Parallel Last Longer?

Batteries of the same voltage and amperage if connected, they seem to last longer with the same voltage. For example, if two 6v 12AH batteries are connected, the resultant would have 6v and 24AH capacity which will back you up longer.

How To Connect Two 12 Volt Batteries In Parallel?

The connection of all batteries in parallel is the same. You have to connect the positive terminal of a 12v battery to the positive and negative terminal to the negative of the other 12v battery to connect them in parallel.

Does Connecting Batteries In Parallel To Charge Increase Amp Hours?

Connecting two or multiple batteries in parallel leads to an increase in the amp-hour capacity in general. However, the voltage will remain the same.

What Happens If You Connect Two Non Identical Batteries In Parallel?

It is recommended to connect two identical batteries in parallel. This is because, when you connect two non-identical batteries, the higher charged battery will charge the lower-charged battery to balance which will not serve your purpose.

## Final Thoughts

Connecting batteries in parallel improves the total run time. However, to get the best out of the batteries, you must connect them correctly. You should never connect old, or batteries with different voltages together. That would either damage all the batteries or fail to power your car.

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