The most common form of a lead acid battery is used in cars and trucks. Golf carts and electric cars and the like also use lead acid batteries. Essentially, every lead acid battery works the same way. They are also prone to the same type of degradation of the inner battery plates called sulphation. A sulfated battery is the most common malady of a dead battery, but as long as an used lead acid battery is mechanically sound, a sulfated battery can be revived. If you have pile of “dead” lead acid batteries out in your garage and you don’t want to buy new ones for your specific project, then this article could be a good discovery that you have found because the de-sulphation methods used here are revolutionary from common methods and effective. Before going to the process of de-sulphation, the bad cells need to be identified first.
Identify the bad cells:-
- Charge your batteries beforehand for at least 12 hours. After that, disconnect batteries from chargers and allow them to rest for 10 minutes.
- Open up all battery caps. If you have sealed lead acid batteries, search in the web for guides on how to open their caps.
- Fill up each compartment to within optimum water levels. This is crucial because in later parts, sparks will be produced and the air column in the compartments which contain hydrogen and oxygen can explode and blow the acid on your face. The higher the water level, the less the explosive air column, and the less likely for explosion to occur on your occasions. Use torch to aid observing water level meniscus.
- Measure the terminal voltage of battery (12v). Fully-charged battery must be in 12v range around 11.8v to 13.0v. If you have something lower than 11.8v, there is a very high chance of cell imbalance in which one of the cells (out of 6 cells) has a problem.
- Measure the voltage of each cell and identify the cells with lower voltages. Attach multimeter probe to one of the terminals and immerse another probe into the cell solution. Continue along the cell holes. A good cell must have at least 2v. Remember the bad cells and note that they would have different colors of plate than other cell plates because of heavy thick formation of lead sulphate crystals which are non-conductive.
Below are the methods for the process of De-sulphation:-
- Attach a battery trickle charger or a computerized smart charger to your old lead acid battery, and allow charging continuously for about a week to 10 days. The extremely slow charging rates dissolve the de-sulphation that kills the battery, and revives it back to being able to hold a usable charge.
- Wire in an electronic de-sulphate device that constantly de-sulphates the battery acid solution. These are available as either ready-to-use units, or they can be built from a kit.
- Add a chemical desulphator to the filling ports on an old lead acid battery. The chemical dissolves the sulphation, and revives old and new batteries alike.
There are certain preventive measures which should be taken before performing the above steps yourself:-
- Must wear goggles and gloves while working with lead acid batteries.
- The electric cells and plates in an old battery must be sound and functional. If these vital components of a battery are damaged in any way, your old lead acid battery will never revive.