please read my comments below which are posts on the subject
Copied from here - http://www.vaportalk.com/forum/topic/16958-single-18650-vs-stacked-18350-batteries/
While the quoted post says they tried an aw 3800 mah. I ran the same test with a red efest imr 2000mah. With similar results.
Copied from here - http://www.vaportalk.com/forum/topic/16958-single-18650-vs-stacked-18350-batteries/
While the quoted post says they tried an aw 3800 mah. I ran the same test with a red efest imr 2000mah. With similar results.
I have 2 Vamos. I set them at 7 watts. I have tested the single 18650 against the stacked 18350 a couple of different ways. My batteries are AW IMR LiMin. The 18650's are 3800 mah and the 18350's are 800 mah. The first way I tested was to put an 18650 in one Vamo and stacked 18350's in the other. Both have a chi forged drip atty and both at 2.2 ohms resistance. I put a #1 on one and a #2 on the other. Placed them side by side and all day went 1,2,1,2,1,2,1,2 etc. Once in a while I would forget which one was next but not often. When it came time to go to bed I checked my notes and found out that I was on my 3rd 18650 and still had the same set of 18350's. All day without changing them. Then I test the 18650 one day and the 18350's for one day. I had changed the 18650 four times for all day. With the 18350's they still had 6.4v(6.2v is low voltage). I am getting well over 60%more vaping time with the stacked setup. Then I wanted to know a little about how this works. It seems that the overhead on a vv/vw is high managing the RMS controller and the voltage booster. With the stacked setup the you have more than enough power to take care of this overhead. With the single 18650 once a great while it would turn off before low volts and I would have to turn it on again and it would change RMS to AV mode. For 2 weeks now, now problems and only have to change batts once a day. In other forums I have read that some people are afraid about melt down and exploding conditions. First: With the Vamo if it were to explode the end cap is designed to blow out away from you and as far as a melt down that gets down to atty's with less than 1.5 ohms resistance. A lot of people don't seem to realise that if you put dual coils of 1.5 ohms your total resistance is .75 ohms, getting real close to a dead short circuit. If you want 1.5 ohms in a dual atty each coil has to be 3 ohms. resistance in parellel devides. Below 1.5 ohms you are doing serious damage to the life span of the battery.......All that said I love stacked batteries.