Anyoune noticed this in their Vamo's? I'm using stacked 18350 config. When fully charged vamo reads 8.3v and drops really quickly (like 5 vape sessions) to about 7.7v, but then takes about a day and a half or 30 sessions to read 6.8v and starts to roller coaster again and craps out at 6.3v in just a few more vape sessions.