Charging the Honor 8 with a 5v charger instead of the 9v quick charger included with Phone

Hi
Is it possible to charge the Honor 8 with a 5v charger safely, without possibly damaging your phone/charger/lead, instead of using the 9v quick charger included with the phone when new .(I understand the quick charger can charge at 5v or 9v, but when charging the honor 8 which supports quick charging it will, as I understand, always charge at 9v)

Thanks
Adam