Hard to say how long it will take but I would say less than an hour from fully discharged (3.7v). Charging after a race probably won't take more than half an hour. Max charge seconds is just a safety feature built into the CE charger. When you charge the battery for the first time look at how many seconds it took and add a little to it in case of problems. So say your battery took 3000 seconds to charge from a discharged state. I'd set the max charge seconds to 3200-3500 so if anything ever happens that is the LONGEST the charger will charge before shutting down.