It is strictly required to check battery visually before controls made with testing equipment. For visual check, you should use a small hand lamp. First of all, external surface of battery is checked with a hand lamp. It is strictly required to check if there is any deformation or fracture in box, cap or adherence areas.
Then, you should check status of battery terminals. You should check battery terminals if there is any deformation, fusion or external intervention. Especially positive terminal of battery should be checked. If there is any pumping-up on positive terminal, it may indicate that battery remains in sulphation position for a long time, which means permanent sulphation. If sulphurized batteries are kept in this position for a long time, then they comes in permanent sulphation position, which is called corrosion. Different from enclosed-system batteries, open-system batteries should also be checked in terms of status in cells, water losses that may arise from time to time or external interventions may easily be detected in this way. Upon checking external surface of battery, it is strictly required to check bottom points. Boxes may sometimes be deformed due to quakes in the vehicle or looseness of connection points. Bottom area may be broken, which cannot be detected with visual check. Electrolyte on broken area is released from cell. In such case, this battery cannot provide desired capacity. If all visual checks are completed and everything is normal, battery may be analyzed with testing equipment.
It is required to connect positive cable of cotter voltmeter to positive battery terminal and negative cable to the negative terminal. After connections are made, press starting current button of device and wait for approximately 8 to 10 seconds. Meanwhile, monitor the needle of cotter voltmeter. Take the first voltage value and voltage values under load so that you can have an idea about failure of battery. In open-system batteries, intensity values in all cells are measured with use of hydrometer in addition to cotter voltmeter test. If intensity values in all cells are on yellow and red area, this means battery starts to be sulphurized. Rectifier charging is required to dissolve sulphate ions on plate surfaces. If our battery is an enclosed-system battery, then surface voltage of battery is measured with a digital voltmeter. If value is below 12.40 volt, it is required to take this battery under rectifier charging.
Battery failures other than sulphation are those that make batteries unusable even if rectifier charging is applied. If battery failure results from production, replacement of battery is provided within warranty coverage. If this results from use of customer, battery will be out of warranty. Failures under warranty, namely failures resulting from production are mostly short circuit and grift breaks.
If positive and negative plates contact each other due to separator breakdown in a cell of battery, short circuit happens. If there is a break in weld lots, grift break arises.
Another failure seen in field other than sulphation and corrosion, which are not covered by warranty, is overcharging and burnt-type failures. This failure results from two main reasons. First, alternator charging voltage is higher than 14,4 volt, therefore battery is overcharged with higher current than desired when vehicle is started. This can be explained with the formula as voltage=current x resistance, which is one of the fundamental principles of electricity.
According to this formula, we can interpret voltage as alternator, and resistance as battery. If alternator limit voltage is not 14,4 volt, but 15,0 volt, battery will be charged as more current than needed. Another reason for overcharging burnt is vehicle driver exposes battery to frequent deep discharge although alternator of vehicle produced charging voltage in appropriate values. To explain this case shortly, when battery is in discharge position, sulphate ions accumulate on plate surfaces. When vehicle is started, active agent spills in time causing performance loss since lower current value produced by alternator is loaded on sulphurized areas and excessive current is loaded on nonsulphurized areas. We may understand overcharging burnt failure if voltage value reduces slowly if battery is loaded with cotter voltmeter test method. If you use open-system battery, the most obvious indicator of this failure when electrolyte color darkens and intensity values are high in cells during visual controls. If you desire to use your battery for a long time, please do not forget to maintain your vehicle and battery in specified periods.