Hi, I have a project that needs to work in a remote location with battery power. I need to install the system, have it switch on 11-V power once after a 2-month wait, and preferably switch the power off after another 4 months. That’s all I need to do, but it must be very reliable and as small as possible.
What I have set up is a PICAXE 08M2 controller (on their “starter kit”), a Grove DS1307 RTC, and a Grove MOSFET. This combination works, but I can’t figure out the power consumption–so I know how long it’ll last. I am also not clear on whether the MOSFET will continue to operate as the battery voltage drops. The battery pack that powers the PICAXE is 3 alkaline AAs.
Someone has suggested that I use a latching relay to save power. I see that the Grove 2-Coil Latching Relay advertises low power consumption. But it also says that its minimum operating voltage is 4.7 V, which I think is too low for the AAs. So may this won’t work unless I figure out a separate battery for the relay. But at 5 V, the battery option doesn’t look easy.
If the MOSFET power consumption is low enough maybe I can keep that. But I don’t know what that is. If anyone can help I’ll appreciate it! Also if anyone knows how low the voltage can go for the MOSFET to operate. Thank you!