Portable charger fan not working

My Ather was taking too long time to charge, I have reported the issue in through mobile app and got response from ather team saying that the bike was yesterday charged in two parts. In case the bike is connected to the charger immediately post riding then the charging time would be more as the battery would be HOT or WARM. So I tried the next charging the bike in the mid night 2am and it took 8hrs to charge from 8% to 100%. Then I had doubt on the portable charger and I checked my colleague who has the 450X and found his charger fan is running and my charger fan is not. Does any one of you had the issue in the first three months as like this ?