I use the rechargeable 1's from Amazon. Forget the name of them. Unfortunately these suck. My safes are in my garage as well but I dont have the luxury of using a plug in dehumidifier. There is no holes punched through in my safe. Stupid question but would it wise to punch a hole in each safe so I can plug in a unit? I'm charging these ones about every 5 days in the fall, winter, spring depending on weather. Thanks for any info