Can a Car Battery be Repaired? The Fixing Procedure

While not the most expensive component in a car, buying a new battery will undoubtedly take a toll on your wallet. Because of this, many ensure they properly maintain and use it. Even if it doesn’t stay the whole car’s life, a battery should at least get to its life span before wearing out. But it may wear out no matter how well you use or maintain your battery.

Most times, the first thing that comes to mind is replacing it with a new battery ASAP, as your car won’t start with a faulty battery. But car owners are always looking for ways to minimize cost, one of which is opting for repairs. And truly, repairing car components is much cheaper than a complete replacement. Hence, prompting the question, can a car battery be repaired?

repair battery

Can a car battery be repaired?

Whether a car’s battery can be repaired depends on the type of battery and its condition. If, you’re using the old unsealed flooded batteries, they can be repaired. These low-maintenance batteries allow you to open the battery and work on it. Repairing or reconditioning batteries involves removing the bad battery cell (battery acid) and replacing them with new ones. This way, the battery can hold a charge and function well.

If, however, you’re using today’s battery which comes sealed and air-tight, repairing it will be impossible. These batteries are maintenance-free and not built to be fixed—a reason they are sealed. So they cannot be taken apart to work on. Here, buying a new battery is your only option.

The only issue with reconditioned or repaired batteries is, they are less powerful than new ones. Fixed batteries usually have only 70% of the strength of a new battery. But that’s a good score, as they can last up to 2 years.

Lastly, while unsealed batteries permit reconditioning, if the battery is broken or cracked, too much damage may have occurred inside, and it may not be able to hold a charge. While AC is on in car, battery will drain out quickly due to poor condition. Repairing it will do no good.

How to recondition a car battery?

Reconditioned batteries can last up to 2 years, giving you enough time to save money for a new one. But be sure that the battery is truly the issue, especially if the battery is still new. Because sometimes, the issue may be a faulty alternator not charging the battery properly or other things possibly draining the battery.

Repairing or changing your battery here won’t help. Instead, you should focus on things draining your battery or what’s faulty. But if you’re sure the battery is bad, you can repair it. It is worth noting that the process of reconditioning batteries is dangerous and could result in burns and explosions if done wrongly.

And therefore best left to the hands of experts since it involves dealing with powerful acids. However, anyone can now repair battery so long they take safety precautions and follow the right steps. If you can’t repair the battery yourself, type car battery repair near me to get experts to fix your battery.

Items needed

  • Protective gear — safety eye google, apron, chemical resistant gloves
  • Distilled water (one gallon)
  • Baking soda (one pound)
  • Battery cleaner (if you have one)
  • Epsom salt (one pound)
  • Big plastic buckets (two)
  • Toothbrush
  • Steel wool
  • Flat screwdriver
  • Funnel
  • Voltmeter
  • Battery charger
Repairing Battery YouTube


  • Ensure your working space is well ventilated.
  • Put on your protective gears.
  • Create a cleaning solution to serve as a battery cleaner. To do this, mix two teaspoons of baking soda and one teaspoon of water. If you have a battery cleaner, there is no need to create another cleaning solution.
  •  Clean corroded battery terminals by applying the battery cleaner to the terminals; scrub off the build-up with the toothbrush. For tough corrosion, use steel wool. Ensure you wipe the cleaned terminals dry before proceeding.
  • Check the battery’s voltage using your voltmeter. If between 10-12.6 volts, proceed. If below 10 volts, you can’t recondition such batteries.
  • Remove the car battery dead cell. To do this, remove the battery lids, then use the flat-headed screwdriver to remove the cell lids; there should be about 2-6 caps. With the cell caps out, carefully pour the cell solution (battery acid) into a bucket. While pouring out the acid, add the baking soda to neutralize the battery cell solution for safe discarding.
  • Next is to clean the battery cells. To do this, use a funnel to pour your battery cleaner into every cell. Replace the battery and cell lid and shake forcibly for 60 seconds. Unseal and pour out the mixture into the trash bucket.
  • Recondition the battery by replacing the battery acid. The cell solution, an electrolyte, is a mixture of distilled water and Epsom salt.  To do this, mix four cups of Epsom salt with distilled water, and mix until it’s clear, after which you pour it into your battery cells with your funnel. Shake for 60 seconds.
  • Now recharge the battery. Set the battery up in a safe space and remove the cell lids, as there might be an overflow of electrolytes when charging. Plug the charger into the battery and set it at a charging rate of 12V or 2 amps. This may take up to 36 hours to completely charge.
  • Examine the battery.  First, remove the charger from the battery and check with your voltmeter. If it reads between 12.4 – 12.6 volts, it’s well charged; if below, recharge for another 12 hours. If it charges up to 12.4, you’re good to go; install the battery. Next is to perform a load test. To do this, turn on your headlights and test with your voltmeter again. If it reads at least 9.6 volts, your battery is appropriately reconditioned.

Can a dead battery come back to life on its own?

A dead car battery cannot revive independently; it needs an external power source to recharge. When a battery dies, it becomes impossible for the alternator to charge it. In this situation, you may need to explore other ways to revive dead car battery.

These include jump starting, charging with special battery chargers, reconditioning, hard cranking, distilled water or Epsom salt solution for low electrolyte, hard cranking, hot harsh method, etc.  If none of these restore the car battery, you may need to opt for replacement.

However, some people claim their dead batteries hours later, allowed them to start their cars. Hence, thinking the battery restored on its own. That’s not self-recharge; see what happens.

Your battery died initially because after using up the battery’s power at its full capacity, a chemical reaction happens internally, creating enough hydrogen gas to block electricity flow among the plates. So when left for a while, the gas disperses a little, opening more conductive plates and allowing you to start your car.

Sometimes, the slightest current left in the battery can be released at sufficiently high currents to start the engine. So it’s not free power; it’s just latent energy or the last charge left in the battery that starts the car.

Can you refill car battery acid?

If the electrolytes are low or dead, you can refill them. For low electrolyte levels, add electrolytes until the plates are covered; this prevents the battery from drying out. If the battery cell is dead, you would need to discard it entirely and replace it with a fresh one.


People often ask: can a car battery be repaired? Yes, car batteries can be repaired if the battery comes unsealed; such batteries can be opened and worked. Reconditioning batteries is an excellent way of reducing costs and saving money, and such batteries can last at least two years.

If you’re using a sealed battery, you can’t repair it. They are maintenance-free batteries and cannot be taken apart. Unsealed batteries that are broken, cracked, bulged, or appear to be in bad shape cannot be repaired as well. In these conditions, you must replace it with a new battery.


Mr. Shafiqule Islam is a graduated Mechanical Engineer and has more than 15 years experience of repairing and maintenance of different brand vehicles like Toyota, Mitsubishi, Ford, Mercedes, BMW etc. He is also giving training to Mechanics. He has started writing to share his practical knowledge to Vehicle Owners, Drivers and Mechanics to keep their cars at best fit.

Recent Posts