1. Stay away from FS-510. It is reverse polarity. if you buy it then you have to only charge their stuff in their charger and never charge their stuff in other chargers. I won't buy 510-T either. It's charger is different enough to damage normal 510 batteries and even Ego batteries. IMO If you want a 510-T buy a 510 manual or mega xl manual + a 510-T atomizer and tanks.
2. Always check your chargers. I have had two %*^(*#)# vendors sell me 510 chargers that I later found out were Ego chargers (420mA output) and these damaged FIVE 510 batteries so they weren't holding charge well and not flashing when low on charge (damaged protection circuits). One of these cables came INSIDE a clone 510 kit. So get a magnifying glass and check all of your 510 cables. The mA output should say something in the area of 150 to 220mA. NOT 400+ mA.
3. Unless you have some big reason why you need auto batteries (like you are a paraplegic or need to vape while using both hands to work) buy MANUAL batteries. The manual 510 batteries are totally sealed on the threaded end. If
juice leaks on the end of the battery you just wipe it up. With autos,
juice leaked onto the end of the battery gets into the battery and at minimum may make the drag switch sticky and slow to turn off (wasting power) and at worst will short and kill the battery.
