Batteries are manufactured, in most cases to correspond with or exceed the vehicle manufacturer’s requirements and specifications.
Nevertheless, it should be clearly understood that wet (filled) lead acid battery is “a live” product. Whether it is in storage or in service, it has a finite life. All batteries once filled will slowly self discharge. The higher the storage temperature and humidity of the storage area, the greater the rate of self discharge.
To ensure the batteries are not allowed to discharge to the point where they are damaged (sulphated) or so incapable of giving designed service life, regular checks of the recharge date label on the back of the battery, and voltage checks of batteries with less than 4 month remaining should be made. It is important to ensure good turn around of stock, first in, first out, especially with slow running stock of low volume lines. Batteries with a voltage of 12.35V or below should be recharged immediately. Recharging must not be effected by means of a rapid charger due to the inefficiencies when attempting to recharge a partially sulphated battery which leads to excessive gassing and damage to the active material grid bonds within the battery, which are critical to ensure battery life.
Ideally use a recharge rate as stated in “recommended recharge rate and period” according to battery type and catalogue instructions. At the end of discharge, all cells should be gassing freely. It is clearly recommended that batteries are left to stand for a minimum of 3 hours after charging to ensure any gases trapped in the upper battery casings are allowed to diffuse into the atmosphere. If a battery has been recharged, the recharge date on the back label should be updated by 6 months after second recharge date by physically notching the label. (Note a maximum of two recharges are allowed prior to sale, and product should not be sold a maximum of 9months after the expiry of first recommended recharge date).