My 510s have been dying a lot quicker than they should. I didn't exactly know what to do, so I just cleaned the threads of the battery and all of my atomizers with juuust a hint of rubbing alcohol (the solution recommended here). I thought all was well and they started acting up a bit.
I put a batt in my PCC and the light starting flickering and going crazy! It was laying completely still and just flickering. My PCC will be a solid red light, then it'll start to blink slowly until it just shuts off, so this whole flickering thing when I just put in the battery was new.
I took out the battery and looked in my PCC. Whoa! I never cleaned it, but I didn't think I had to, for some reason. I took a dry cotton swab and cleaned out the charging port for the battery and I was shocked as to what came out. Dark, brownish-black crud was stuck to the charger! Yuck! I put the battery back in and VOILA! Stable red light! Once it was done charging, I was happy! It didn't take three clicks to get the LED light on ( don't ask, this all relates to the PCC
). My batteries are now lasting as long as they did when they were brand new! 
Lesson learned: Clean your battery and atty threads, but DON'T forget about cleaning the PCC!
I put a batt in my PCC and the light starting flickering and going crazy! It was laying completely still and just flickering. My PCC will be a solid red light, then it'll start to blink slowly until it just shuts off, so this whole flickering thing when I just put in the battery was new.
I took out the battery and looked in my PCC. Whoa! I never cleaned it, but I didn't think I had to, for some reason. I took a dry cotton swab and cleaned out the charging port for the battery and I was shocked as to what came out. Dark, brownish-black crud was stuck to the charger! Yuck! I put the battery back in and VOILA! Stable red light! Once it was done charging, I was happy! It didn't take three clicks to get the LED light on ( don't ask, this all relates to the PCC


Lesson learned: Clean your battery and atty threads, but DON'T forget about cleaning the PCC!