Lead-Acid Battery Troubleshooting

As one of the most prominent battery systems, you can observe lead-acid batteries everywhere, from cars to domestic inverters. The capacity is excellent, and you can use them for thousands of cycles before needing replacements or repairs. They are easily accessible, too. Unlike solid-state batteries, you don’t need to hire a team of engineers. Just walk into your nearest electricals store and get one that suits your needs.

However, it is not without faults. Recent studies have shown that thermal runoff wastes a lot of energy, and it is hard to dispose of them in an environmentally friendly manner. Their utilization also results in the owner running into various problems. If you wish to minimize all that, then you’ve found the correct link! This is a thorough guide on lead-acid battery troubleshooting for any issues you may encounter using one.

Lead-Acid Battery Not Holding Charge: How To Fix!

If your battery is not holding a charge, then it may suffer from either of the below-mentioned redundancies.

Lead-Acid Battery Not Holding Charge

1. Improper Connections

The simplest solution to getting your lead-acid batteries to charge again is to examine the connections. In case your battery is in a confined space, like the hood of a car or a small compartment close to the primary junction box. That can result in a few wires stretching too far or meshing together to get disconnected. So, you need to examine the connections and check whether any cables or screws have come undone.

2. Reduced Water Level

Most lead-acid batteries use a solution of water and sulfuric acid to function as an electrolyte. The water is essential to balance out the excess sulfate ions. Failure to do that results in lead sulfate deposits that prevent the battery from holding a substantial charge.

Thus, you should use a hydrometer to check whether the water levels in the battery are adequate. Ideally, the water-to-acid ratio should be 65:35. A decreased level calls for refilling with distilled water, as mineral or impure water can cause unwanted reactions with other chemicals like lead oxide and sulfur dioxide.

Why Is My 12 Volt Lead-Acid Battery Not Charging: How To Fix!

12-Volt lead-acid batteries have smaller cells than their higher-capacity counterparts. Therefore, it is much easier to lose electrolytes through evaporation or continuous charging/recharging cycles. That is why experts advise you to replace your car batteries every 3 to 5 years, depending on how often you drive your car.

Still, if your 12-Volt lead acid battery has charging issues early on, it is probably due to less electrolyte. You can check which cells are lacking and add a sulfuric acid solution with a 65:35 water-to-acid ratio using a syringe. In case you are unsure about dealing with a corrosive solution, visit your nearest battery repair shop to get a top-up.

Why Does a Lead-Acid Battery Heat Up After a Long Time: How To Fix!

Lead-acid batteries have more thermal runoff as compared to solid-state batteries. Thus, leaving them without use and exposed to the elements heats them up. Not all of the components within the battery are inert, as the sulfuric acid and lead electrodes can react with each other. Moreover, if exposed to heat, the terminals can get hot and react with the sulfuric acid fumes to accelerate the rusting process.

So, if you wish to prevent your lead-acid battery from heating up after a long time, it would be best to follow a few critical steps:

  • Never charge a lead-acid battery to more than 80% if you know you’re about to store it for a long time.
  • Use insulated terminal covers and don’t leave any cables attached to the terminals.
  • Keep the battery away from sunlight and excessive humidity.
  • Balance the electrolyte levels within all the cells. Use distilled water to add the cells that have less electrolyte.

Why Does a Lead-Acid Battery Lose Charge: How To Fix!

Lead-acid batteries lose charge over time, even if you’re not using them. It happens due to open-circuit chemical reactions, i.e., the components of the battery reacting with each other with no connection to a load. The lead from the terminal plates can react with the sulfate ions to form lead sulfate, which reduces the capacity to store charge. Moreover, concentrated sulfuric acid can evaporate from the terminals.

To fix it, you need to ensure that the battery terminals are secured. Check the seals of the terminals for possible leaks and swap the cover case in case of any seeps or cracks. The storage area of the battery matters as well. You should store your battery as close to room temperature as possible, with a reliable way to vent out the toxic gasses as safely as possible.

Overcharging Lead-Acid Battery: How To Prevent It!

There is no sugar-coating the fact that overcharged lead-acid batteries are potential fire hazards. Overcharging reduces the battery’s lifespan and can cause the toxic sulfur gasses to leak faster, creating health issues for everyone around. While many people have charging anxieties, it doesn’t help to overcharge the battery.

In case you wish to prevent overcharging your battery, there are a couple of precautions you can take. It is ideal to connect a multimeter to measure the open circuit voltage during charging. For a 12-Volt battery, it is best not to exceed 13.2 Volts. In addition, your neighborhood battery repair shop may have a charger with a voltage cutoff. It automatically disconnects the battery once it reaches a certain charge level. So, it is more efficient to spend a few bucks and charge your lead-acid battery from there to ensure safety during use.

See full this video: Batteries Vent & Explode, With High Current Overcharging

Revive Lead-Acid Battery: How To Fix!

Your lead acid battery can drastically reduce efficiency if they get excessive lead sulfate deposits. Often, it can result in the battery dying out. If you desire to revive such batteries, it is best to first clean the sulfate deposits before adding adequate electrolytes. You’ll need a multimeter, insulating gloves, and a hydrometer as well.

In order to revive a battery, you should add water with Epsom salts. They react with the lead sulfate deposits and let the waste dissolve in water. You can then drain the solution and add in the electrolyte with the appropriate concentration. Keep in mind that, since the amount of lead is reduced, you can only revive a battery a few times, depending on its capacity. After some time, you’ll have no choice but to get a replacement.

See full this video: 200th Video!!! Fixing / Reviving Batteries With Epsom Salt

Lead-Acid Battery Overcharge Protection: How To Do It!

Overcharged lead-acid batteries constitute a danger you don’t want to have in your home. Fortunately, you can take a few measures to prevent it. Use a multimeter to measure the charging state regularly and ensure that it doesn’t exceed the rated capacity. Furthermore, you can apply a voltage-cutoff charger that automatically disconnects once the battery reaches specific charging levels.

See full this video: 12v lead acid battery overcharge protection test

Lead-Acid Battery Failure Symptoms: How To Know!

Your lead-acid battery displays a few telltale signs that it is about to fail in the coming months. A few notable ones include:

  • A foul stench is present around the area where your store the battery
  • Bubbles or fumes exhumed from the terminals
  • Not charging to its maximum rated capacity
  • Leaks and cracks present on the protective casing
  • Excessive rusting on the terminals and cables connected to it

If you spot any such signs, it is a good idea to repair the battery yourself or visit a battery maintenance center near you.

FAQs – Frequently Asked Questions

How do you bring a Lead-Acid battery back to life?

You can bring a lead-acid battery back to life by renewing the electrolyte or using fresh electrodes. In some cases, replacing the terminals and wiring can be enough to bring new life to your lead-acid battery.

How to revive a battery that won’t charge?

Your battery is probably not charging due to excessive sulfate deposits on the electrodes. You can solve it by adding Epsom salts and cleaning the terminals with a basic cleaning solution like sodium bicarbonate.

How to maintain a Lead-Acid battery?

Lead-acid batteries require a fair bit of maintenance despite what the manufacturers claim. You can do it with a few simple steps:

  • Check the charging levels from time to time using the multimeter.
  • Clean the battery terminals every few months.
  • Swap the electrolyte if the charging/recharging cycles are not balanced anymore.

How long to charge a Lead-Acid battery?

A lead-acid battery takes about 5 to 6 hours to charge from 0% to 100%. However, it is not a good idea to drain a lead-acid battery completely. So, it is best to charge it from 50%, which only takes around 2 hours.

How do charge a new Lead-Acid battery?

You can charge a new lead-acid battery by connecting it to a suitably rated controller or an inverter. If you don’t have one at home, it is best to visit a professional battery repair shop near you.


And that’s all there is to lead-acid battery troubleshooting. Did we miss out on anything? What are your thoughts on maintaining lead-acid batteries? Let us know in the comments below.


  1. PowerTech, Lead Acid Battery Downsides 
  2. MK Powered, Why Do Lead Acid Batteries Fail? 
  3. Instructables Workshop, How To Revive Old Lead Acid Batteries 



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