Comment by eitland
1 day ago
There is always the option to use battery (some modern mines use this),for example RAAMS.
The problem is of the enemy know you use only mines that work for max n hours or m days they just wait for n + 1 hours or m + 1 days.
There is a lot more to say about this, but there are probably people way more qualified than be here to explain it.
There are tons of possible options in between n hours and 3 decades