Car Batteries

Which Battery Cable To Connect First?

Mike Cross
Updated Dec 25, 2022

In short: Connect the new battery -> positive then negative; and reverse order when disconnecting the cables from the old battery -> disconnect the negative first, then the positive

Their are a variety of reasons why you might remove your battery from your car, boat, mower, or other equipment with a battery. It could be to charge it or to replace it.

Well, no matter why you removed the battery it brings up a common question when you go to put the battery back in and that is why wire to connect first.

Their is a debate amongst people on if you should connect the positive wire or the negative wire first. Well, after reading this article you will have an answer and reasoning to this question.

Which Battery Cable To Connect First?

Which to connect first?

So, which terminal should be connected first when reinstalling a battery. Some people say it doesn’t matter because no circuit is being made when only one wire is connected.

While that is true that not circuit is being made thru the battery, it is still possible to complete the circuit. That is why the answer to which wire to connect first is the positive wire.

Why connect positive first?

The reason you connect the positive first is that the negative is the ground wire. You don’t want the ground wire to be connected first because then the circuit will be completed as you try to connect the positive which could lead to sparks.

These sparks could shock you or worse short out the battery or other components. That is why it is important to make sure that the positive is connected first.

With the positive connected, then when you go to connect the ground sparks will not occur because it will go into the ground wire. This will keep you safe as you connect the wires and also keep the components in your vehicle or equipment safe.

Other times

This same question also doesn’t always come about when reconnecting a battery, but instead when jumping a battery. When jumping a battery also want to make sure that you connect the positive clamp first and then the negative clamp.

This is for the same reasoning as when reconnecting the battery. It keeps sparks from happening and shorts from happening. This applies to the good battery as well as the dead battery.

Connect the positive clamp first and then the negative clamp
Connect the positive clamp first and then the negative clamp when jump a battery


When disconnecting the battery or jumper cables it is the opposite. You disconnect the negative first and then the positive.


There are a variety of times when you need to connect a battery into your car or other piece of equipment such as a mower or boat. When you need to connect the battery it is important to connect the positive first and then the negative.

This keeps you safe as well as the equipment safe. You might have heard that it doesn’t matter, but after reading this you can not see that it does.

A circuit can be made when connecting the battery be it the wires touching something or the tools that you are using. If it is already grounded and the positive wire touches something than a spark will occur. This won’t happen if it is the other way around though.

Reconnecting your battery isn’t the only time that you will be connecting wires to your battery however. It is important when jumping a battery and connecting jumper cables to also remember to connect the positive terminal first.

This applies to the good battery and the dead one. It is a good habit to always connect the positive first and then the negative and when disconnecting to disconnect the negative first and then the positive.

After reading this you now know the answer to which battery cable to connect first.

Mike Cross
Life is too short to drive with stock audio

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2 comments on “Which Battery Cable To Connect First?”

  1. Thank u i do not know that you connect the positive first when putting on a new battery awesome thank you

  2. Without an on off switch can I leave the positive wire in charge controller and use the negative wire to turn sola shower on and off

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