Battery longevity I have no idea as of 9/31/19. Very please with this find. I use the small like on other ones and they feel like it slid out to the opening of my ear canal. This plays music directly to a USB Headphone DAC/Amplifier (I bought an AUNE X1s, made in China by a specialist manufacturer. Es un producto archiconocido y de calidad a un precio increíble, 25?. I love every part of these headphones and they would be the best headphones that I?ve ever owned before except for the fact that you cannot use the headphones to actually activate your phone like you would most headphones. I ordered 5 pairs of possible wedding shoes off of Amazon and kept these (chose them over 2 pairs from Badgeley Mischka). Does what it says, bought it for cousin. Well within budget but not cheap crap. Thankfully, someone was home to yank the flaming charger of doom out of the wall, but if wed left the house it easily could have caused a major fire.