I use this at my truck yard where I don't have internet or power but it has a long lasting battery.

I use a pre paid sim card from T-Mobile and you can get alerts as well

https://www.amazon.com/dp/B098DY1FHH/ref=cm_sw_r_apan_i_QKSF3YCYB8GRK5JQB37B?_encoding=UTF8&psc=1