Afterwards, lead terminals must be controlled whether they have any deformation, melting or external intervention. Especially, positive magnetic pole of the battery should be controlled. If there is a swelling at the positive magnetic pole of the battery, this may be an indication of battery’s long-term position in sulfation or being passed to the position of permanent sulfation. F sulfated batteries are kept in this position for a long time; they pass to a permanent condition of sulfation which is called corrosion. Unlike closed system batteries, inside condition of open system battery cells should also be controlled. Any water loss or any external intervention can be clearly seen in this control. Lower points of battery must be controlled after controlling outer surface. Sometimes it may occur some deformations on the box arising from shocks in the vehicle or looseness of connections. It may happen some cracks - which cannot be identified by visual inspections - in lower area. Electrolyte is not in the cell anymore in the area where crack occurs. Therefore, this battery is not able to provide desired capacity. Battery can be analyzed with test equipments when all visual controls are appropriate.
The positive cable of voltmeter with holder should be connected with positive magnetic pole of battery while negative cable is connected to negative magnetic pole. It is pressed to starter button after making necessary connection and it must be expected 8 to 10 seconds. Pointer of voltmeter with holder is followed in this procedure. It is obtained information about battery failure by taking first voltage value and loaded voltage value. In open system batteries, in addition to voltmeter with holder test, it is also measured density values of all cells with the assistance of hydrometer. If density values of all cells are in yellow and red area, this means that battery sulfation begun. In order to solve sulfate ions on the surface of the plate, it should be performed rectifier charging process. If the battery is a closed system battery, battery’s surface voltage is measured with assistance of a digital voltmeter. If the value is lower than 12.40 volt, it must be performed rectifier charging for this battery.
Other battery failures except sulfation are the failures that battery cannot be used again although it is performed rectifier charging. If battery has a failure arising from manufacturing, it is changed under warranty; if there is a failure arising from vehicle or user, then it is subject to out of warranty operations. Most common failures arising from manufacturing - therefore under warranty - are short-circuit and grift breakage failures.
· In-grift failure notification
· Grift breakage
Short-circuit failures occur if positive and negative plates contact to each other due to any puncture in any cell of battery. Grift breakage occurs in case of any breakage on welding connections.
· Out of warranty notification
· Corrosion (Permanent Sufation)
Other failures encountered except sulfation ad corrosion –which are out of warranty - are failures like overcharging, burn etc. These failures have two main reasons: first, when alternator charging voltage is over 14,4 volt, the vehicle is charged with more current than it needs when it the vehicle is started. This situation can be explained with basic principles of electricity: voltage= current x resistance formula.
According to this formula, we can consider voltage as alternator and resistance as battery. If alternator limit voltage is 15,0 Volt instead of 14,4 Volt; then battery will be charged more than it actually needs. Another reason of overcharge burn failure arises when driver often exposes vehicle to deep discharge although alternator of the vehicle produces appropriate charge voltage. This situation can be explained briefly as the following: When battery passes to discharge position, sulfate ions are gathered on the plate surface. When vehicle is started, the current produced by alternator loads less current to sulfated areas while it loads excessive current to non-sulfated areas. Over the time, this situation causes active ingredient spillage on the plate resulting performance loss. We can detect overcharge burn failure if voltage value drops slowly when loading is made with voltmeter with holder test. If the battery is an open system battery, blackening of electrolyte, having high density value are indicators that can be identified during visual controls. If you want to use your battery for a long time, do not forget to make both your vehicle and your battery maintained in specified periods.
Battery must be visually controlled before being tested with test equipment. It will be absolutely helpful if a small flashlight is used during visual inspection. First outer surface of battery is controlled with the help of a flashlight. Is there any deformation on the box, cover or seal areas? Is there any cracks? These controls must be performed.