Serial VS Parallel RV Battery Wiring: What You Need To Know (2023)

Abattery bankis a group of two or more RV batteries connected by wiring in series or parallel. This allows you to store more energy than would be possible with a single battery, increasing amperage, voltage, or both.

There's always a bit of confusion around this topic, so today we're going to try to explain what you need to know about wiring RV batteries in series or parallel.

What is the difference between batteries in series and parallel?

Connecting batteries in series increases the total voltage but not the capacity (amp hours) of the batteries. For example, two 12V batteries rated at 100 amp hours connected in series equal a total output of 24V but still have a capacity of 100 amp hours.

Connecting the batteries in parallel increases the total capacity but not the voltage of the batteries. In this example, two 12V batteries rated at 100 amp hours connected in parallel still equal 12V output but increase the capacity to 200 amp hours.

Regardless of whether you connect RV batteries in series or in parallel, it is best to use batteries of the same voltage and capacity (even brand names if possible). It's also a good idea to make the cables connecting one battery pack to another as long as possible.

How to wire batteries in series

For RV applications you will generally only connect the batteries in series if you are using 6V batteries. Remember that connecting batteries in series increases the voltage. The typical RV is designed for 12V.

Pro tip:Not sure what battery voltage you need? Read our article12 volt or 6 volt RV battery - which is better?

So if you put two 6V batteries in series, just connect the positive terminal of one battery to the negative terminal of the other. This gives you the 12V power that most RVs require.

After connecting the two 6V batteries in series, connect the RV positive lead to the open positive terminal of one 6V battery and the RV negative lead to the open negative terminal of the other 6V battery.

When wiring in series, you never want to connect the RV's positive and negative leads to a single battery. Connecting the RV charging leads (positive and negative) to separate batteries keeps the setup balanced and helps the batteries last longer.

If you want to use 6V batteries to further increase your capacity, you can connect each paired series in parallel to avoid increasing the voltage to more than 12V. This is called a series-parallel circuit, which we'll get to in a minute.

How to connect batteries in parallel

To wire two 12V RV batteries in parallel, simply connect the two negative terminals together and then the two positive terminals. This keeps your voltage at 12V (which is ideal for your RV) but doubles your capacity, meaning you have longer battery power before you need to charge it.

Even if all your terminals now have wires connecting the two batteries, that's fine. You can connect more than one wire to each terminal. That's how it works.

To connect your two 12v batteries, which are now connected in parallel to your RV, simply connect the RV positive lead to the positive terminal of one 12v battery and the RV negative lead to the negative terminal of the other 12- volt battery on

Similar to connecting two batteries in series, you don't want to connect the RV charging cables to a single battery. Disconnecting two different batteries helps keep the setup balanced and extends battery life.

Differences in charging batteries

There is not much difference between charging batteries in series and charging a single battery in parallel. The basic idea is the same.

With a single battery, you would connect the positive output of the battery charger to the positive battery post. I would then connect the negative output of the battery charger to the negative terminal of the battery.

As long as you have your battery banks wired correctly, the idea is the same. With a single battery, the RV's positive charging cable is connected to the positive battery post and the negative charging cable is connected to the negative post.

Whether you loada bank of two 6V batteries or charge two 12V batteries(or more) in parallel, you would connect the positive output of the charger to the positive terminal where the RV's positive charging cable is connected. You would also connect the charger's negative output to the negative terminal where the RV's negative charging cable is connected. This ensures that the batteries in the bank are charged evenly.

Make sure your charger has the same voltage as the bank you are charging. A 12V charger can charge a 12V series bank or a 12V parallel bank. However, if you have a special case where you are putting 24V, 48V or some other voltage in series, you should make sure your charger matches the voltage.

You can also charge individual batteries within a bank using a charger that matches that battery and charge them individually. For example, if you have four 12V batteries connected in series but only one 12V charger, you can connect and charge each battery individually.

Eine andere Sache, die Sie sicherstellen sollten, ist, dass Ihr Ladegerät für die Chemie der Batterie, die Sie laden, ausgelegt ist.Most deep cycle batteriesbut have similar loading profilesLithiumbatterienYou need a slightly different voltage.

Using a serial chain

There is a possibility that you may want to connect a battery bank (string) in series to increase the voltage for specific applications. perhapsyou have a great solar systemand you want to power an inverter, which in turn can power 120V devices from battery power.

In this case you can string some 12V batteries together to get a higher voltage, say 24V. If you still have a 12V system in your RV for things like house lights, control panels, etc., you will need to do this Use a DC-DC converter.

In an emergency, you can connect the 12V RV charging cables to the positive and negative terminals of a single 12V battery in series to power your RV's 12V system. This unbalances the string, making it less efficient and possibly shortening its lifespan.

Serial and parallel port

Remember when we said you could actually connect more than two 6 volt batteries together and still remain compatible with your RV's 12V system? Well, that's how you do it.

You now know how to connect two 6V batteries in series. Simply connect the positive pole of one battery to the negative pole of the other. You now effectively have a 12V battery bank.

However, if you wish to use 6V batteries to further increase your capacity, you can do so by connecting a pair of 6V batteries in series with another pair of 6V batteries in series (or multiple pairs). connect by connecting these pairs in parallel.

Once you have your 6V pairings simply wire them in parallel by connecting the open positive terminal of one pair to the open positive terminal of another pair and do the same for the open negative terminals by connecting the open negative Connect the terminal to the open negative pole. Terminal.

Then, from one end of the battery string, connect the RV's positive charging cable to the positive battery post. At the other end of the battery string, connect the RV negative charging cable to the negative battery terminal. Remember that it is okay to connect the RV charging cables to a connector that is already connected to the connector of another battery.

Safety devices in serial and parallel connection

The most important safety device in a series or parallel circuit is the cable that connects them. This is a very important aspect not only for efficiency but also for safety. Make sure it is rated for the amount of current that will be drawn through it.

Another safety device when connecting RV batteries in series is the charger in your RV's converter. This is especially important if your RV is plugged into the mains most of the time. Some older chargers can overcharge batteries, which can damage them. You want to make sure your RV converter has a 3-stage or smart charger that allows for safer charging.

Also, perform regular battery maintenance. Keep the terminals clean, and if you have flooded lead-acid batteries you might want to play it safe and check the water level in them.LiFePO4 or Lithium batteriesThey don't have regular maintenance.