I have two attys (Joye 510) and two manual
batteries (Joye 510) I purchased in a kit two years ago that still work! I just got a ego-t type b kit which is way different then I am use to. I wonder if they will last like my original 510 kit. I also have a disposable 306
ecig (pv I hate calling them ecigs) that still works but that battery doesn't hold a charge nearly as long as the 510s. The disposable unit is actually a month older then the 510's it was my very first pv! I also just got some Vison clearomizers and a fluxomizer kit. Now here is the real scoop on all that, see I have had other 510
batteries and attys in the last two years that I purchased after the initial kit. I don't have any of that hardware because it died or I burnt it. I have had a battery or two that didn't last a month, same with a atty. I bought some el cheapo who knows who made it products and I have also had some name brand stuff go down or even DOA. Part of it is quality control, how you take care of the equipment, how hard you are on it and of course there is the luck of the draw.
I am sure this probably didn't add anything useful to the topic but I wanted to throw in my two pence worth.