I'm not very techy, so forgive my ignorance, but...Is the Anker 20100mAh portable charger under the 100Wh required for airline travel? Amazon mentions 5V output which, if used in the calculation, would be just over 100Wh, but I think I read somewhere that it is actually rated for 3.7V, which would put it under the 100Wh limit. Does anyone know for sure? Is it actually written on the product anywhere?