Looking for SIM card recommendations

[Dean Pichon]

Last year, I started using a GSM Controller to control the heat in my hanger. As cold weather approaches, I need to reactivate the SIM card. The AT&T sim card I used last year will cost at least $25 (a lifetime of turning on and off the heat) but the account expires after only 90 days. Has anyone found an inexpensive source of minutes/msg units that have a relatively long "shelf life"? (Ideally, I would like something that lasts 6 months or so, so I don't have to spend time messing with sim cards...)

Thanks,

[Mopar591]

I dont have any experience with that system. But what about using a go-phone (disposable cell) sim card. I know you can purchase minutes and text messages. It seems like it would work, don't know if the card expires.
Just an idea