Here’s How You Can Make A New Lead Acid Battery Out Of Your Old Dead Battery


Lead Acid batteries were introduced back in 1859 and since then, there has not been much change in the composition and manufacturing technique of lead acid batteries. With all the alternative sources of energy being explored and implemented; we are seeing a rising trend in demand of Lead acid batteries. However, these batteries have a high cost and you will need to spend quite some money to replace them (average life of commercially available deep cycle batteries is 1.5-2 years) when they die out on you. This is where we come in with our guide on how to rebuild a battery from your dead battery. Read through and also pay attention to the health and hazards tips at the end.Lead Acid Battery Lead Acid Battery 3

Alright, so how do you build a battery from an existing dead battery and more importantly why does the battery die? Which component gives out on you? The answer is positive plates found in your battery. The case is more likely if they are the pasted positive plates. The anodic corrosion eventually gets to them and breaks them down. This results in a decrease in battery’s capacity and consequently failure.

Lead Acid Battery 7You can recover the oxides (covered later in the article) from the positive plates that have fallen victim to the anodic corrosion and use it to make paste for the new plates. The negative plates suffer from sulfation but that can be ignored. So; we will be using the negative plates to make a new cell with the paste that comes from oxides. This means that you’ll be building a 3 cell battery from 6 cell battery.

Lead Acid Battery 5Now to get to the job’ remove the positive plates and have them placed in a metal container, which can take some beating. Use a hammer or anything that is hard that can transfer impact to turn these plates into powder. Once you have crushed the plates, remove small pieces of lead and grid from the mixture by sieving the contents. Now you are left with black/grey powder. Mix this powder with sulfuric acid and water to form a paste which will be placed into the plate’s grid structure and cured. Curing is a crucial process and should be done carefully. Mix the fiberglass and glass fibers that have been recovered from the separators to strengthen the paste. Once the paste has been applied you will need to cure the plates, which is usually done at 30 degree Celsius in high humidity for about 48 hours. At home, just put them in a pot that is filled with water into the oven and keep an eye on the water level. After curing, let them dry for about 3-4 days. Lastly, drain the acid into a container and do not discard it; we will need it later on.

Bring out your gloves and protective clothing. First off, cut the top off the battery and leave about 5 mm of plastic around the terminals. Now you need to cut the interconnection between the cells and remove the cells from the case.

Lead Acid Battery 8Now you need to perform the process of forming in which, active materials are formed on the new plates. The idea is to pass electric current and then reverse the direction and continue the same procedure for about say 30 times. If you continue indefinitely you’ll destroy the plate.

Let’s make some electrolyte, shall we? Add acid to water (NOT the other way around) and do it slowly while stirring. The mixture will get hot so you better bring compatible equipment. Alternatively, you can buy a sulphuric acid solution with 1250 sp gravity from a battery shop to use as a battery electrolyte.

Lead Acid Battery 4 Lead Acid Battery 2Now all that is left is placing the plates back into the case, sealing the top and filling it with electrolyte. There you go; you’ve just made a battery out of your dead battery. Try this out at home and let us know how it worked for you.


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Comments 13


  1. I need to understand percentage composition of battery electrolyte (thd volume of water and concentrated sulphuric acid to mix).

  2. Thank for valueble infomation, if u upload a video in this topic it will be very helpful, and i want to know how to and materials should be used to make battery plates – & positive plates thanks

  3. Interesting article! I would not recommend building a new battery out of your old though. It is not an easy job. If you still decide to do it, make sure to work very safe as the lead-acid is very dangerous.

  4. Oh! Really? How about getting a new battery, seems easier eh? And what exactly are you suggesting the battery be used for?

  5. We will be cutting power to 50% (we will be building 3 cell battery from 6 cell battery) and too much effort is required to build this battery.

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