When it comes to the purchase of automobile batteries, we have to mention CCA, which is the cold start current value. Refers to the amount of current released by the battery at a specified low temperature (usually-18℃) 30 seconds before the voltage drops to the limit power-off voltage. This is an important index to measure the cold start ability of automobile battery. It is necessary to ensure that the CCA value of the purchased battery is not lower than that of the original automobile battery.
The "nominal CCA value" is marked on the outer packaging of the automobile battery, which is the CCA value that the battery can reach when it is designed.
In actual operation, technicians will also use hand-held detector to measure CCA value of vehicle battery, so as to help judge the health status of battery and determine whether it is necessary to replace the battery. However, it should be noted that the CCA value measured by the hand-held detector does not represent the actual CCA value of the battery, but is an estimated value. It measures the voltage and internal resistance of the battery, and then calculates the CCA value of the battery according to the metal specific gravity of the conventional battery technology.
Therefore, there is a certain deviation in the hand-held detector, which can not be used for CCA detection of new batteries, but can only be used to assist in judging the health status of batteries. However, the accurate CCA value of automobile battery can only be measured by discharging the battery with large current at the constant temperature of-18℃ in the laboratory.
In addition, due to the technical differences between different brands, the internal structure of the battery will directly affect the accuracy of the measurement, so the CCA value measured by the hand-held detector can not be used as a lateral comparison between different brands of batteries. According to the data, the results of measuring different brands of batteries by hand-held detector are some on the low side, some on the high side, and some are even hundreds of amperes higher than the real value. Take valta, a world-famous automobile battery brand, as an example, the CCA value measured by its hand-held detector is low. The reason is that valta battery adopts advanced lightweight technology.
The specific gravity of internal metal is different from other brands of batteries, and the handheld detector is calculated according to the conventional battery specific gravity algorithm, which leads to the low display value when detecting CCA of valta battery. However, the true CCA value of the new valta battery is actually much higher than the nominal value.
Because the CCA measured by hand-held detector is inaccurate and limited by conditions, we can't measure it in the laboratory. So, which car battery has better CCA performance? At present, the outstanding cold start performance in the market is valta AGM automobile battery.
Enhanced PowerFRame dual-volt sharp grid technology, such as highway current path design, is adopted to strengthen the thickening current concentration area and achieve excellent conductivity. The patented lead paste formula increases the contact area with sulfuric acid, and can still maintain strong current output in cold state.
Therefore, we must not blindly take the hand-held detector as evidence of the CCA level of the new battery. CCA performance of automobile battery depends on brand and technology.