Most important protection against EMP’s is to keep your unit disconnected from grid.
Second is to keep them disconnected from solar panels with long cables as these will act as antenna’s.
If you’re still afraid of EMP’s with these two points secured: You will need to store your unit in a faraday cage. Any metal box will do the job. For example inside an old (all metal) fridge that is not in use.
North Korean state media have repeatedly gave warnings of a potential high-altitude electromagnetic pulse, or EMP, attack against the United States. A lot depends on the level of the EMP that happens. From communication disruptions to it frying the electrical grid and most electronics completely. I used to be a prepper. I takes too much time and money to do the survival thing right. I just have to hope for the best if SHTF.
If anyones interested here is a PDF of a Unclassified Gov. EMP-Protection-Resilience-Guidelines to protect infrastructure and essential equipment against electromagnetic pulse (EMP) threats Guidelines.
This is a possiblity now. High solar activity expected at the end of 2023.
If you want to see a SHTF solar EMP scenario check out this video.
Not all concrete reinforcing bars can become a Faraday cage. They must be welded together and have good conductivity to ground. Here in Puerto Rico only special buildings require this type of grounding. All concrete homes have reinforcing bars just tied together. I know because I helped to build a roof extention on my parent’s home around 1968 to increase the carport size, and we tied many rebars together with pieces of steel wire.