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All You Need To Know About Batteries continuedInformationEN1 Test @ -18°C 10s to 7.5V, 10 seconds rest than 60% ofcurrent to 6V where time should be greater than 73s.EN2 Test @ -18°C 10s to 7.5V, 10 seconds rest than 60% ofcurrent to 6V where time should be greater than 133s.The rating of the battery obviously varies subject to batterydesign, but for example a battery rated at 1000A according toEN1, could only be rated at 920A according to EN2. Theinformation of which standard the battery is rated is currentlyheld within the ETN number e.g. 550 034 050550 = > 12 Volt 50Ah battery034 = > Is a specific number to thatbattery whichgives details of lid type, life, vibrationresistanceand also whether the battery conforms toEN1or EN2 high rate050 = > High rate current in this case 500AThere are currently nearly 2000 individual battery numberslisted on the ETN data base by different battery manufacturersand users. This currently makes it unclear to the customer towhat rating the battery is capable of meeting EN1 or EN2without access to the listing.In order to minimise confusion, Yuasa currently use the longerestablished American BCI SAE rating for cold cranking ampswhich is the current to deliver 30 seconds to 7.2V at atemperature of -18°C. This is seen as a fairer comparison togive a balanced view of the batteries durability and startingperformance.The evolution of the Conductance tester into the marketIn the last ten years, comparatively inexpensive conductancemeters have entered the market which are able to determinethe specific internal resistance of an automotive battery usingthe principles of the AC Wheatstone bridge (which you mayremember from school days). The clear advantage of thesedevices is that they are portable, easily operated, no sparkingrisks from carrying out traditional high rate load “drop” test anddeliver results in just a few seconds.DisadvantagesThe disadvantage of the conductance tester is that they all usea standard algorithm (program) to estimate the CCA readingfrom the measured internal resistance reading. The valuesgiven by these meters are not comparable with thosedetermined using the laboratory test equipment wherebatteries are physical discharged under real high dischargeload, at a temperature of -18°C. Due to differences in batterydesigns it is not possible to give a perfect relationship betweeninternal resistance and actual performance in the laboratory.Laboratory testing shows that the algorithm used inconductance testers penalises batteries where the batterydesign has been optimised (with heavier high density, fineporosity plates) for durability/cyclic endurance than thosedesigns optimised for high rate performance.For the evaluation of new factory fresh batteries differentreadings can be seen depending on the manufacturers platedesign and acid density. Even significantly different readingscan be obtained between different brands of tester. Expandedplates give a higher reading than a cast plate, as the cast platehas a full frame construction for improved conductivity. Thegrid size can be reduced and made thicker to access the activematerials toward the bottom of the plate. This design differencefor example has a difference on the conductance readingswhere the tester correlates to the CCA reading based on astandard formula. The testing of new batteries is more complexas testing under the EN50342 standard requires the battery tobe conditioned after a number of cycles which alter theconductance of the paste and hence causes more variation intester data produced.For this reason, Yuasa and other major battery manufacturersrecommend that the confirmation of the compliance of unusedbatteries to the EN or BCI can only be determined usinglaboratory testing and that digital conductance tester are notsuitable to evaluate the performance of new unused batteries.3. Open-Circuit Voltage and High-RateDischarge Testers.1. Measure the open-circuit voltage of the battery using a digitalvoltmeter or a multimeter. To obtain a stable voltage, thebattery should not have been used or charged for aminimum of 3 hours before checking the voltage.2. If the voltage is below 12.40V, charge the battery inaccordance with Section G.Note. This type of tester will only give an accurate result ona fully-charged battery. A common mistake is to use thistype of tester on a discharged battery, and to judge that thebattery is faulty if a cell is seen to ‘boil’. A ‘boiling’ cell on aflat battery does not mean that the battery is faulty.3. Apply a current-load equal to half the SAE CCA coldcranking Amps for 15 seconds. For example, discharge a600A battery at 300A. Observe the voltage during this timeand record the voltage after 15 seconds. You will find theCCA in the Battery Specifications section of the Catalogueor on the label. Use an approved, calibrated tester.4. If the voltage after 15 seconds is stable and above 9.60V,the battery is in a satisfactory condition with no faults.5. If the voltage is below 9.60V after 15 seconds and it isunstable, normally falling quickly, the battery should bereplaced.4. ‘Drop Testers’.1. ‘Drop testers’ have 2 spikes that are pressed into the topsof the battery terminals and a simple voltmeter to check thedischarge voltage.2. We do not recommend the use of these testers as:• They are potentially unsafe to use as most types produce aspark when the spikes are first pressed into the terminals.• The discharge rate is similar for all sizes of battery, and sothey do not give a good indication of battery-condition.• They give misleading results on discharged batteries.526