How to Connect Two Dry Cell Batteries Together

Batteries have a wide variety of uses. Batteries can be doubled, tripled, quadrupled, ad-infinitum. Most dry cell batteries are 1.5 volt, we know them as D cell, C cell, etc. Some rechargeable batteries are only 1.25 volt. Wet cell batteries are two volt and we find them in our cars. Here is how to connect two deep cell batteries together.


  1. Image titled Connect Two Deep Cell Batteries Together Step 1
    Attach flashlight batteries. If you have a two cell flashlight you put the batteries in the tube of the flashlight with the little bump in facing the bulb, this is the positive terminal and the flat end is the negative. Then put the second battery in the bump first. This places the positive of one battery in contact with the center bump on the back of the bulb and the positive of the second battery in contact with the negative of the first battery, or Positive to negative also know as series. Once you screw the end cap onto the flashlight, completing the circuit and turn on the switch you have completed the circuit. The batteries being in series also means the voltages add together. You are now powering a three volt bulb with two 1.5 volt batteries. If your flashlight takes three batteries in the tube you have a 4.5 or 5 volt bulb. A five cell flashlight will have a 7.5 or so volt bulb.
  2. Image titled Connect Two Deep Cell Batteries Together Step 2
    If you take those same dry cell batteries and hook them up parallel, i.e., positive to positive and negative to negative instead of adding the voltage you will add the amperage, generally measured in milliamps, you would have a 1.5 volts at double the milliamp of one single battery. Maybe you have noticed some AAA batteries are slightly bigger around than others. If a device needs 3 volts, more amperage just means the batteries will last longer, as long as the bigger batteries will fit.
  3. Image titled Connect Two Deep Cell Batteries Together Step 3
    Fix a car battery. Your car battery has six 2 volt batteries hooked plus to minus. If your car battery has the little caps where you put water in (they all have them but some are hidden) each one of those is a 2 volt battery. If you have a test meter put the negative lead on the negative post of the car battery and the positive lead into the acid of the nearest cell, you will get 2 volts. If you put the positive lead into the acid on the next cell you get 4 volt, and so on. If you place the lead into a cell and the voltage does not go up you have a dead cell. Hooking the positive terminal of one car battery to the negative post of another car battery will give you twelve 2 volt batteries in series which gives you 24 volts, be careful. If you hook up 10 car batteries in series you will get 120 volts, DC, be very careful. 120 volts DC will burn out a 120 volt light bulb because the bulb is designed for AC current and running it on DC will over heat it. That is another discussion.
  4. Image titled Connect Two Deep Cell Batteries Together Step 4
    If you hook up 2,3,4,10 car batteries in parallel, positive to positive to positive etc., and negative to negative to negative etc. you will get 12 volts with a lot of available amps.


  • Unless your hands are wet, touching the positive and negative posts of up to a twelve volt battery at the same time won't shock you.


  • The acid in a car battery is Sulfuric acid it is best to wash it off if you get some on your hand. If you get it on your hand it will burn you eventually. If you get it on your hand and wipe your eye you may go blind! Don't do anything stupid. Common baking soda will neutralize acid, might have some on hand just in case. Common baking soda will also neutralize the acid in the car battery and kill the battery.

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Categories: Electrical Maintenance