That dead battery found in your car, motorcycle, tractor, boat, golf cart or EV is called a Lead Acid Battery. Lead Acid batteries are the most economical battery. Their construction is simple compared to the construction of say a Lithium Ion battery. The down side of lead acid batteries is the weight and the fact that they go dead when they are left discharged for even short periods of time. The maintenance of a lead acid battery is just the opposite of a cordless drill battery because the technology is different. Lead acids do best when left with a full charge.
When you go out to start your riding lawn mower or motorcycle in the spring you quickly find out that these types of batteries don’t hold a charge well when left unattended for several months. You also find that even after you jump start your mower or motorcycle that the battery just isn’t the same as it once was if it even charges at all. The reason for this is because the lead in the battery is exposed to uncharged raw acid when the battery slowly discharges over time. The lead in the battery simply rusts, thus blocking the flow of electricity and ability to charge properly. Luckily there is an affordable, readily available household compound that will reverse this.
To breathe new life into your lead acid battery you will need to first purchase the chemical Magnesium Sulfate. You probably just asked yourself “where in the WORLD do I get THAT!” This is actually a very easily found substance. However you won’t find it on the shelf of a store if you are looking for magnesium sulfate but you will find it on the shelf of almost every department store and pharmacy if you are looking for EPSOM SALT. I recently purchased 2 gallons of distilled water for $1.46 along with 4 lbs of Epsom salt for $2.39 at Wal-Mart. That’s enough to treat all eight batteries in a comuta-car for less than 50 cents each!
To recondition your lead acid battery you will need Epsom Salt and a quart of distilled or rain water. Do not use tap or well water! Warm up the distilled water to about 150 degrees (very hot but not boiling). The temperature doesn’t need to be exact and will still work even if the water is at room temperature, it just won’t work as well. Mix 10 heaping table spoons full of Epsom Salt into the quart of water and stir until most or all is dissolved. Then simply pour this warm solution into the individual cells of your dead battery just as you would normally put water to maintain the acid levels. Then charge your battery over night. Do not attempt to put Epsom Salt directly into your battery because it will not dissolve properly into the battery acid, only water will dissolve Epsom Salt. Most dead batteries will be low enough on fluid that adding this solution will not over flow the battery. It is only recommended to add ½ quart of solution to an average size battery or one quart for a golf cart size battery. If your battery is already full of fluid then you will need to drain some of the acid to allow for the Epsom Salt solution. After adding the solution put the caps back on and shake the battery a bit to mix all the chemicals. Then charge battery overnight. If battery does not appear to have good capacity after the overnight charge, don’t give up. Sometimes it takes a week to 10 days for the Epsom Salt solution to “work” on the battery plates. Agitation is important. It is difficult to get the Epsom Salt solution to thoroughly mix with the acid in your battery because of the battery plates and baffles. One of the best mixing methods is to simply drive the vehicle (if the battery works at all) Some batteries have caps that come off the top to maintain the acid levels easily but low maintenance batteries require a bit more work to recondition. A low maintenance battery has its top sealed shut to prevent evaporation but it also prevents easy reconditioning. These batteries can still be reconditioned but you will have to look for the “shadow” marks on the top plastic that shows the holes into the cells. Simply drill holes in the plastic to get access to the cells then pour in your warm solution. You will then want to plug these holes with plastic plugs that can be found at most hardware stores. When purchasing a new battery it is recommended to look for the batteries that you can easily repair in the future should the need arise. It is also recommended to purchase a small solar or battery maintenance charger to keep your unused batteries charged over the winter to prevent this problem from happening in the future. This method works most of the time but not all the time. It depends on how bad the cells are decayed. This process can also only be done 3 to 5 times before the cells are worn out, prevent battery damage with a maintenance or solar charger!
So how does this work, and what is the success rate? When a battery loses its state of charge it has become more of a base than an acid, so the electrical power it generates through the chemical reaction of the magnesium sulfate and the lead plates inside the battery has been reduced. By adding water instead of the proper chemical solution you are accomplishing nothing. So, unless the lead plates inside your battery have broken off, which is rare, this procedure almost always works. The success rate is about 98% (on batteries that have never had this treatment). I have done this to many batteries (mainly golf carts) and only a few have failed. However, I’ve found this can only be done 2 to 3 times before the battery is no longer able to be resurrected. Considering the cost of materials is only a few dollars, I think this is well worth trying.
ALWAYS WEAR SAFETY GOGGLES AND GLOVES WHEN WORKING WITH ACIDS!