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Is It Safe to Charge a Car Battery Indoors? | What to Know

Have you just made it home before your car battery decided to die? Are you having trouble turning it back on, and you have a crucial meeting in the morning? Whatever the reason, there are times when you may be deciding whether or not to charge it indoors.

The practice of charging a car battery indoors is not entirely reliable or recommended. By charging your car battery at home or in a confined space, you might get the corrosive sulfuric acids stuck to your clothes and skin. Moreover, hydrogen build-up can cause the battery to explode. 

Just realized that a trip to the mechanic is inevitable. As a last resort, and with the right precautions, you can charge your car battery indoors or at home. Read on to find out how to do it in the safest way and without causing additional damage.

How Can I Charge My Dead Car Battery at Home?

Man connects the charger terminal to the car battery

As we have mentioned, this practice can turn out extremely dangerous and cause damage to people and properties. However, in extreme scenarios, you might consider getting your car back on the road by resuscitating the battery at home. If your vehicle is having trouble starting, the lights and indicators to switch on promptly, or there is no dome light, you should know that your car’s battery is about to die.

Of course, you could opt to jump-start it as a quick, immediate fix, but this won’t solve the problem in the long run. If you are not too happy about having to take your car to a mechanic, you can find out all the steps (and precautions) you need for the job below.

What You Will Need

If you have no experience related to the electrical functioning of your car, you should allow a professional to complete this task for you. However, if you are familiar with batteries, car mechanics, and electric circuits, you could try to charge the battery at home. You will need:

  • A jump box (vehicle battery charger)- Click to see Amazon listing
  • A voltmeter
  • An extension lead or cord (AWG gauge)
  • Safety glasses or goggles
  • A fire extinguisher
  • Effective ventilation
  • A stable and sturdy surface to place the battery
  • An apron or clothes that you don’t mind ruining in the process

How to Charge Your Car’s Battery

The method of changing the battery of your car is not one of the easiest or most straightforward ones. However, here you can find step-by-step guidelines that can help you complete the task at home without the help of a professional. Remember to handle the battery with care throughout the process!

  • Step 1 – start the project by wearing your glasses or safety goggles. The sulfuric acid can inadvertently spark while you are holding the battery and cause long-lasting damage to your eyesight. If you are concerned about residual acids destroying your clothes and skin, opt for a sturdy apron and gloves as well. 
  • Step 2 – Find a flat, sturdy surface that will be able to stand the weight of the battery. Depending on your specific batter, this component can weigh between 14 and 22kg. Ideally, you should place the battery on a concrete floor, away from any item that could catch fire, such as oil, wood, or paper. Also, if you have a garage at your disposal, you should opt to do the job there, away from your home furniture.
  • Step 3 – Pick up the battery charger you have selected and set its voltmeter to 12 volts. Moreover, pick a low amp setting. The combination of those factors will ensure that your battery is charging slowly, which, in turn, will help with desulfation. Such a process can help to restore the capacity of the battery and offer you a higher amperage output.
  • Step 4 – find out what type of battery you have by examining the component. If your vehicle boasts a start/stop technology, its battery will most likely be an AGM or EFB. These kinds of batteries need a specific charger. Speak to the local store to find out what type of charger you need if you are not sure.
  • Step 5 – Select the type of battery you are dealing with among the settings of the charger. Now, using the extension cord, connect the battery outlet to the outlet in your garage or room.
  • Step 6 – Attach the red clip of your charger to the battery’s positive terminal and the black clip to the negative terminal. Now you are ready to turn on the charger. Continue to charge the battery for 6 to 8 hours, avoiding any process’ interruptions. Lastly, avoid overcharging the battery as this can damage critical internal components.
  • Step 7 – after 6 or 8 hours, check the voltage of your battery with a voltmeter. After setting the dials within the 0 to 50 range, you can proceed to disconnect the clips, starting with the red one.

The battery is full when the voltmeter shows a value similar to 12.6 to 12.8 Volt. If the display shows anything below 10Volt, you will have to keep charging your battery.

The Best Place to Charge Your Car Battery at Home

Since it is safer to bring your car to a professional, there is no ideal place to do the job at home. However, if you don’t have another choice, you should pick a room that benefits from continuous and adequate ventilation. In this case, a garage would be perfect.

Moreover, the room or area of your property should be isolated and closed off, so the charging battery cannot cause damages to people, furniture, and other items. Lastly, the room should boast a fire alarm and an extinguisher.

Can a Car Battery Catch Fire?

Melted Car Battery in Engine Compartment From a Fire

There are several potential risks associated with charging your car battery at home. First and foremost, the battery can catch fire. While it is not extremely common, cables and the extension cords you are using can cause sparks, which, in turn, can set the battery on fire. Another risk derives from the build-up of hydrogen that the battery creates during the charging time, which can also explode.

Aside from these two significant risks, charging a car battery at home has other side effects, which you should take into consideration. Of course, the threat of fire or an explosion can cause long-lasting damages. However, you should not underestimate the effects that the sulfuric acid in a lead battery fluid can have on your health. Such acid is highly corrosive and one of the most dangerous acids out there.

Indeed, if it gets in contact with your eyes, it can cause permanent or long-term blindness. If you find residual sulfuric acids in your clothes and your skin has been contaminated, proceed to wash the area multiple times to cool it down and clean it thoroughly.  

Final Thoughts

As we have seen, charging your car’s battery indoors, at home, or in a confined environment is possible. However, it does not mean that it is either safe or recommended. Such a procedure can be detrimental for the well-being of the battery and lead to its early decay. Replacing the battery of a car can be extremely pricey.

However, this project can have severe consequences if something goes wrong along the way. The battery could explode, the extension leads could cause a spark, the sulfuric acid could contaminate your skin and eyes, and you could even report damages to your eyesight. If there is no other choice aside from charging your car battery at home, make sure the room benefits from proper ventilation, and you are wearing all the necessary PPE. Otherwise, just dispose of the battery properly.

For more, check out 20 Car Emergency Kit Essentials | Detailed List.