[HELP]Smok Alien - Passive battery drain or dead batteries?

Hi all. Does anyone who still uses a Smok Alien 220w notice that their batteries are completely flat. I put fresh batteries in an hour or so before I went to bed and woke up to flat batteries. Is this a common thing? Ive upgraded the firmware to V1.3.2 but it hasnt helped. Any suggestions or time for a new mod?