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How to Charge a 6-Volt Positive Ground Battery

by Thomas West

Although most vehicles use a 12 volt battery that negatively grounded, some vehicles that were still in use as of 2010 use a 6-volt electrical system that is positively grounded. All vehicle batteries must be grounded to a substantial metal object such as the vehicle’s frame or engine block, whether it be a negative or positive ground system, although the charging instructions are slightly different for each.

Step 1

Switch your battery charger off, or if your charger does not have a power switch, unplug the charger’s power cord.

Step 2

Connect the negative, or black, cable from the battery charger to the negative battery terminal by squeezing the alligator clip at the end of the cable so that the jaws open. Place the jaws over the terminal and slowly release the clip so that it is firmly attached to the terminal.

Step 3

Connect the jaws of the positive, or red, cable from the battery charger to a substantial metal part of the vehicle such as the frame or engine block in the same fashion as in Step 2. Choose a location as far away from the battery as the length of the cable allows.

Step 4

Move the 6v/12v voltage selector on your charger to the 6-volt position. Plug the power cord into a wall outlet as far away from the battery as the cord and cables will allow. Turn the battery charger's power switch on.

Step 5

Charge your battery anywhere from one to several hours, depending on the output of your charger, the size and cranking-amp rating of your battery and the condition of the present charge of the battery. Check the instructions with your battery charger as to how long you should charge your battery. (Note: some chargers come with a gauge or an indicator light to let you know when the battery has been fully charged. Some chargers will also shut off automatically when the battery has been fully charged.)

Turn off the charger’s power switch when the battery has been fully charged. Unplug the power cord from the wall. Remove the positive, or red, cable from the vehicle’s frame or engine block, then remove the negative, or black, cable from the negative battery terminal.


  • To determine if your vehicle is positively or negatively grounded, check your owner’s guide. In the absence of an owner’s guide, follow the battery cable that is attached directly to your vehicle’s frame or engine block to the battery. Whether this cable is attached to the positive or negative battery terminal determines your electrical system’s polarity.


  • Any battery that is not charged properly, such as from incorrectly attached cables or overcharging, may explode, possibly causing serious injury and property damage.
  • If while being charged your battery seems hot to the touch or if acid is bubbling from the vent caps, disconnect the charger from the battery immediately. The battery may not be able to take a charge and will need to be replaced.

Items you will need

  • Battery charger

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.

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