510 Addy's - Not Created Equal ?

[Twisted]

So I have the starter set 510 (and a second on the way), I wanted to use both Addys and bats at the same time - Kinda rotate them.
The first one has been running strong but the second one is a little strange.. it will work some what ok for the first 3-4 draws (after priming it) and then it gets a heavy draw and the vap is sometimes good and other times not there.
Could it be bad somehow. I did try cleaning it a fue times but it goes back to the heavy draw...

 

[RsL]

Unfortunately some attys work better than others, and it's not just the ones for 510s. It could also be your battery so I would try the atty that works good with both of your batteries.