Occasionally, I received battery for warranty claims and they are suspected to be good but merely discharged. I'd used smart charger (between ctek and xtreme) to charge until they are 100% according to the charger and sent them back. I check CCA is also good. But sometimes I get the same complains again. Recently, I decided to check the electrolyte after the smart charging and realized that some were still in the poor range, even though it's supposed to "fully charged". Then I continued with the charging using a dumb charger at boost voltage (15.0V) until the current absorption drops to almost zero. After which I measured the electrolyte is now good. It seems to be me, the smart charger are not so smart after all and stopped charging too soon. I'd like the electrolyte to be in the good range, before sending them out, but also I'm afraid that I was overcharging the battery. Any thoughts?