These days everybody have so many different gadgets in their bags and of course you need the same amount of different power chargers to keep these gadgets alive during travel. Awhile ago on my trip to Europe I bought step-down voltage converter as most of my cameras and other gadgets were made for American market, i.e. 110/120 voltage and in Europe it is 220/240V. So I packed that bulky and heavy voltage convert into my backpack. In the middle of my trip I looked to the back of one of my battery chargers and what I found?
It can work without any voltage converts. Only thing I needed was power plug adapter. Maybe not all devices are so universal even these days, but most of digital camera battery, phone, iPad and laptop chargers don’t need any voltage converts. So before buying any additional stuff check the back of devices you own. Such things as voltage converts are very heavy. It can weight about 1kg(~2.5 pounds) and with so much weight restrictions on current flights it can be real problem to take such heavy things with you.