What are the qualities to look for in a portable charger? There are some important things to consider when looking for the best portable charger to suit your needs, including the mAh, size, and the devices you plan to charge. These days, the best portable phone chargers typically have USB-C power delivery with PD fast charging for speedy juicing. Can I take my portable charger on a plane? Yes, but with one crucial rule: portable chargers must always go in your hand luggage, never in the hold.