How to Set Up a Dual Battery System

PDF download Download Article
The best way to add another battery to your car
PDF download Download Article

It makes sense if you think about it: more batteries means more power! Running dual batteries can give you more capacity or more volts, depending on how you hook it up. Fortunately, it’s actually really simple to connect 2 batteries together. You just need to do it correctly and safely. To make it easier, we’ve answered some of the most common questions that people have about what it takes to run dual batteries.

How to Install a Second Car Battery

The best way to install or set up a second car battery is to connect the negative of the first batter to the negative of the second battery with a battery cable. Then, use another cable to connect the 2 positives.

Question 1 of 5:

Can I run 2 batteries in my car?

PDF download Download Article
  1. Most cars use a 12-volt system and you can give your electrical system a boost by running 2 batteries at once. You’ll have literally twice the battery capacity if you wire them for 12 volts or twice the output if you wire them for 24 volts. [1]
    2. Advertisement
Question 2 of 5:

How do you hook up dual batteries?

PDF download Download Article
  1. Use a battery cable to connect the negative of one battery to the negative of the other battery. Then, use another cable to connect the 2 positives together. This will double your total battery capacity without increasing your amps or volts. [2]
  2. To connect 2 batteries in a series, connect the 2 negatives of each battery to the positive of the other batteries with a battery cable. This will double your volts from 12 to 24. [3]
    • Alternatively, if you want to jump start your car battery, look at the owner's manual.
    • Touch the positive cable on your car and the positive point on the car providing the jump. [4]
    • Then touch the ground on the terminal of your car and the car providing the jump. Find a separate ground that is not on the battery. The top of the strut tower nut is a good spot and works well. [5]
    3. Advertisement
Question 3 of 5:

Can you run two batteries one alternator?

PDF download Download Article
  1. Your alternator actually recharges your batteries while your engine is running. If you have 2 batteries connected, and they’re the exact same type, then your alternator will charge both of them. [6]
Question 4 of 5:

What is a dual battery isolator?

PDF download Download Article
  1. A dual battery isolator is a device that you can use to connect 2 batteries together without causing 1 battery to drain the power of the other battery. It essentially keeps the batteries isolated from each other. [7] To install one, connect the positive terminals of each battery to the isolator and connect a ground wire to a safe grounding location such as the frame of the car. [8]
    2. Advertisement
Question 5 of 5:

Is a dual battery system worth it?

PDF download Download Article
  1. If you have a bunch of extra devices hooked up to your vehicle, such as lights and a sound system, they’re likely a major drain on your battery. By having 2 batteries hooked up to your vehicle, you have double the capacity to handle all of your devices. [9]

Expert Q&A

Ask a Question
200 characters left
Include your email address to get a message when this question is answered.
Submit
      Advertisement

      Video

      Tips

      Submit a Tip
      All tip submissions are carefully reviewed before being published
      Name
      Please provide your name and last initial
      Submit
      Thanks for submitting a tip for review!

      Warning

      • Always use caution when handling batteries so you don’t shock yourself.

      You Might Also Like

      How to
      Test Your Batteries
      How to
      Make a Homemade Battery
      How to
      Charge a Power Bank
      7 Easy Ways to Stop Your Roku Remote from Blinking
      How to
      Clean Battery Terminals
      How to
      Create a Potato Battery
      How to
      Recharge Batteries
      How to
      Charge NiMH Batteries
      How to
      Store Batteries
      How to
      Use AAA Batteries As AA Batteries
      How to
      Check Lead Acid Battery Health
      How to
      Create a Battery from a Lemon
      How to
      Clean Battery Corrosion and Build Up
      How to
      Safely Neutralize and Clean up Battery Acid
      Advertisement

      References

      1. ↑ https://www.hotrod.com/articles/wire-2-12-volt-batteries-to-make-12-volts-or-24-volts/
      2. ↑ https://youtu.be/dZzinsfI2Y0?t=31
      3. ↑ https://www.hotrod.com/articles/wire-2-12-volt-batteries-to-make-12-volts-or-24-volts/
      4. ↑ https://www.theaa.com/breakdown-cover/advice/using-jump-leads
      5. ↑ https://www.theaa.com/breakdown-cover/advice/using-jump-leads
      6. ↑ https://youtu.be/dZzinsfI2Y0?t=58
      7. ↑ https://nerdtechy.com/best-12v-dc-dual-battery-isolator
      8. ↑ https://youtu.be/0GmpbJ9-xt8?t=42
      9. ↑ https://nerdtechy.com/best-12v-dc-dual-battery-isolator

      About This Article

      Thanks to all authors for creating a page that has been read 110,669 times.

      Did this article help you?

      Advertisement