Proper Way To Recharge Lead Acid Batteries


It is important to know the proper way to recharge lead acid batteries.  Over time, water loss leads to the reduction of the electrolytes.  These electrolytes move across flat lead plates in order to create energy.  As the water, and thus the electrolytes, diminish, it is important to recharge the battery in order to maintain proper working order.

Types of Chargers

There are two main types of chargers that are generally used.  One type of charger gives off a single voltage for the output of generated energy.  This means that the voltage cannot be changed.  The other main type of charger is an intelligent type of charging system and can change the amount of voltage sent out based on the usage and state of charge in the battery.  Using the single voltage charger is not recommended.  The use of the intelligent charging system can reduce maintenance because it can determine whether or not to send an extra pulse of voltage to help reduce the amount of lead sulfate on the plates which can minimize voltage output of the battery.  When the battery is recharged, the lead sulfate turns back into lead and sulfuric acid, making it once again optimal conditions for the battery to work properly. 

How Charging Works

When electricity is conducted through the water, it is broken back down into hydrogen and oxygen.  Because these two elements are flammable, batteries must be vented outside.  It is important to make sure to add water to the battery occasionally because the gassing that occurs during battery use as well as recharging causes water loss.  Sometimes, it is possible to overcharge a battery, which can cause the relief caps to open and vent, which also leads to water loss.  One point that needs to be made is to remember that the temperature can affect the charging cycle of a battery.  The cooler the temperature is around the battery, the more of a charge the battery will absorb.  The ideal charging temperature is between fifty nine and seventy seven degrees Fahrenheit, or fifteen to twenty five degrees Centigrade.

How to Properly Recharge a Lead Acid Battery?

If the battery being recharged is not deemed maintenance free, the first step to recharging a lead acid battery is to clean around the caps on the top of the battery.  This prevents dirt and corrosion from falling into the battery cavities when the caps are removed.  Once the caps are removed, making sure to be wearing safety glasses, look inside the battery itself.  The water level should be equal in all the battery cells.  The plates should be completely covered by water by at least three quarters of an inch.  Make sure the water levels are not too high, however, because of the creation of gasses as the battery is used and/or recharged.  Most batteries will have a distinct fill to line for the purpose of not overfilling the battery with water.  When refilling, make sure to use only distilled water.  Do not use tap water because the chemicals that tap water is treated with can interfere with the breakdown of hydrogen and oxygen which helps create the energy used to run the motor.  It can also, at times, cause combustion.  Replace the caps before attaching the clamps to the battery.  The red clamp of the charger is attached to the positive battery post terminal, and the black clamp is attached to the negative battery post terminal.  Always connect the negative first to reduce risk of shock.  If there is enough time, set the battery charger to the lowest amperage level to avoid damage to the plates and to minimize the heat that causes the water to evaporate.  This will help lengthen the battery life, even though it takes longer for the battery to fully recharge. 

Using the Correct Charge

It is possible to use either too little of a charge or too much of a charge from the supply source.  To use too little of a charge could result in using an undercharged battery.  Using a battery that is not fully charged can lead to sulfation, which is the build up of sulfuric acid on the plates.  This build up can lead to the reduced movement of current within the electrolytes.  This reduced movement, in turn, leads to a reduced charge.  If the charge is too violent or unsupervised, it is possible for the current to become great enough to damage the plates physically.  It is also possible for the heat to build up and escape, which could lead to an explosion.  It is recommended to start charging with a low voltage and slowly increase it, watching the maximum level of voltage to ensure that the battery does not overheat, which can destroy the battery by causing the plates to buckle. 

Most battery chargers are set to the appropriate voltage.  It is important to periodically check the battery's charge with a voltmeter in order to make sure the battery is getting a charge, without overcharging it.  As with the initial phase of the charging, the final phase of charging should be gradual, with a lower level of voltage applied to the battery from the charging source.  The length of time to recharge lead acid batteries can very depending on the beginning charge.    Most batteries require between four to eighteen hours to charge, depending on beginning charge and the voltage that is supplied by the power source. 

If this is too much detail, there are intelligent charging systems that will read the beginning voltage of a battery, determine the settings of the voltage throughout the charging cycle, and determine when the battery is fully charged.  These charging systems tend to be expensive, but require less technical knowledge of the battery.

Once the battery is fully charged according to the voltage meter, turn off the power to the charging power source.  Remove the clamps from the battery terminal posts, being careful not to touch both posts at the same time to avoid accidental shock.