Review on GRT8-M1 Multifunctional Time Relay with 10 Functions - Efficient Delay Time Control Solution for AC/DC 12V~240V - DIN Rail Mount by Dan Tsourvakas

I cannot say enough good things about this device. As 12V is the lowest value of its input voltage I wasn't sure how it would perform in an automotive application but as it turns out it's happy down to 10V and below. It gets a little warm during operation, so don't connect the cable. This can drain the battery, but as a shutdown timer killing its own energy, that's fine. (Program E, with some diodes to make it turn on first.) All programs are useful too, I'll leave a few of these for general purposes. The time dial is not very accurate. ; the range between 1% and 10% is much smaller than it appears. This can be difficult to test if you're taking a very long time, but the percentage applies no matter what decimal interval you set. So the workaround is to find a short interval and test it: Let's say you want a 7 day delay that you set to 70% of the 10 day interval. Set a 10 second interval instead and adjust the percentage until you get a 7 second delay. Then simply switch to a 10-day interval and that's it!