I'm not too car-savvy but I want to start working on my car on my own. My first challenge has arisen: replace battery.

Do I need to concern myself with being shocked while trying to change the battery? Do I need gloves or will it be safe to replace the battery without them if the car is off?

4 Answers 4


Gloves are not essential, but highly recommended

When replacing a car battery there are three potential hazards that relate to safety:

  • electrical hazard - the battery is capable of generating 100's of amps' worth of current. You want to avoid shorting the two terminals with something like a wrench, cable or hand jewellery. In this regard, gloves can help reduce the risk of shorting the battery with hand jewellery, but the prudent thing to do is not do anything to short the battery terminals.

  • chemical hazard - battery acid is highly acidic and not to to be messed with. In case the battery water overflows or develops a leak gloves would be essential here, though I don't expect this to be too much of an issue while changing maintenance-free batteries.

  • falling hazard - batteries are heavy and can cause considerable damage if one were to fall on your toes. Gloves won't do much good here (unless they provide better grip).

In all situations, the onus is on you to be careful while replacing the battery. Wearing gloves will not guarantee you your safety.

  • 2
    It is important to realize you need to take rings and jewelry off while working on or around batteries. If they were to arc on the battery, it will literally fry you. You can easily lose a finger if it was to arc. Commented Sep 15, 2015 at 20:58
  • @Paulster2 My socket wrench is pure metal (including handle). When I'm taking off the battery clamps this wont spark me will it?
    – Jaken
    Commented Sep 15, 2015 at 21:24
  • 4
    @JakenHerman - Effects like this are what I'm talking about. If your jewelry should create a circuit between the positive and ground. You could do the same with a wrench, which would become superheated if kept in the circuit long enough, but you cannot let go of a ring as it is attached to your finger. Commented Sep 15, 2015 at 21:40
  • 3
    @Paulster2 thanks for sharing that. I have changed many batteries in my time, and never taken off my wedding ring. Gold is an excellent conductor of electricity, but I never thought about that. From now on, I am taking off my wedding ring.
    – user4896
    Commented Sep 16, 2015 at 1:31
  • @Snowman - No doubt! When I went through mech school in the Army, they showed us worse than that. I never work with my rings on, no matter what. Look at what happened to Jimmy Kimmell and that was just an accident in his kitchen! Commented Sep 16, 2015 at 1:34

Do I need to concern myself with being shocked while trying to change the battery?

12V is too low to present any significant electric shock hazard.

The biggest hazard when working on batteries is shorting the thing out. This leads to a massive release of energy which can lead to severe burns. Some precautions that can be taken to reduce the risk.

  • If you have any metal rings (or other jewlery) either remove them or cover them with something insulating.
  • Disconnect the terminal that connects to the cars chassis (usually the negative) first and reconnect it last.
  • Think about what tools you use. Try to avoid using any tool that could short the batter terminals if dropped in the wrong place. If all your tools are bare metal preffer a short tool over a long one.

When disconnecting a battery always remove the negative terminal first. This breaks the circuit and neutralizes the possibility of a short circuit. When reconnecting the battery always connect positive terminal first. Never underestimate 12 volts : Under normal conditions the outer skin resistance is high enough not be an issue. However if you have open cuts the resistance of the exposed flesh underneath is highly conductive and could result in serious injury even with 12 volts. Gloves and safety glasses are a good idea when exposed to sulfuric acid and lead exposure from the battery terminals. FYI:The car body is connected to the negative terminal.

  • Provided you aren't working with a Positive Earth vehicle. Commented Apr 27, 2016 at 9:29
  • Most modern vehicles are negative ground or earth. Old models vehicles are Positive earth usually from U.K. If yours is positive earth then reverse the process.
    – Old_Fossil
    Commented Apr 27, 2016 at 14:54

In addition to the other answers:

  • if the tools you use are exposed metal, wrap some tape around the handle to insulate it.
  • After you've removed one battery cable, cover the exposed terminal. This prevents the cable end from contacting the terminal again.

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