I second the ego-t 18650 mod. Been a while since I looked at prices--maybe $20. I too wanted a backup that would use the 18650s I have in my Lava Tube. Add an eGo charger, and I have a backup charging system for the 18650s too. After trying them out for a few days, I found the batteries lasted longer on a charge than my in LT. I also use RBAs, wind them somewhere around 2 ohms, and find that's the setup I'm using these most of the time now.
They have 2 'voltage' modes--unregulated (starts high and drops as your battery discharges) and regulated (I think they claim 3.2v until battery is spent.) I use the latter mode, and get a consistent vape up until the last 10-20 puffs. Then the lighted button will flash, telling me to charge. Only complaint I have is that the button is flush--you can't really find it by feel, so I use a different battery when I need that feature (in my case, a smaller battery, with a button I can find without looking, on a lanyard, while driving)
They have 2 'voltage' modes--unregulated (starts high and drops as your battery discharges) and regulated (I think they claim 3.2v until battery is spent.) I use the latter mode, and get a consistent vape up until the last 10-20 puffs. Then the lighted button will flash, telling me to charge. Only complaint I have is that the button is flush--you can't really find it by feel, so I use a different battery when I need that feature (in my case, a smaller battery, with a button I can find without looking, on a lanyard, while driving)
