I was asked about my favorite and or most useful battery powered devices I own. The selection is more difficult than I initially thought. Removing the more mundane devices (cell phones, computers etc); I ended up with a massive number of devices!
I needed to further trim down the list, or this post would go on forever....
The ones listed in the post needed to be process critical, or just fun. So the Geiger counters and dosimeter are to be left out. This also eliminated my battery powered hand tools, even though I use them a lot; but let me arrive at a few special ones.
First, the device that can save a life. I have an inductively couples hand held unit used to check for dangerous voltages.
Anyone that even considers doing any electrical power work should start with one of these! When placed close to an active (hot) circuit, and the test button is pressed, the unit warbles and lights up. It is also a non contact unit, so insulation (your best friend) remains intact!
I can't even tell you how many times I've been told that the breaker feeding what I'm working on is turned off, only to verify it is still on with this sniffer! It is also Very simple to use, making it a tester you can hand to a neophyte; and expect good results. I have used it to safely troubleshoot control circuits and Christmas lights. This one sees a lot of use, and is critical safety equipment!
The next one is in the fun category. I always wear a watch, because I hate being late! This is my latest choice;
I pick watches that are watertight, and this one's Good to 3 atmospheres. It caught my eye because it is also a skeleton watch, that is see through; and that amused me. It has kept good time, and I've received a lot of comments on my watch...definitely fun, LOL!
The last one is part of my SHTF inventory. When the system crashes, as current spending guarantees; cell phones will not continue to work very long.
So, since my prepping includes transferring excess supplies between four family homesteads by waterway; we need to be able to communicate. I also have enough of these to use them tactically, to coordinate homestead defense.
This is a UHF ham radio with a 5 watt output setting.
These are inexpensive now, but will become critical after SHTF occurs. We will have a private network with a range of about 50 miles, due to the lake surface helping propagation. There are over a thousand channels in this specific radio, so we will simply disappear. A regular network time will ensure good communications, allowing for mutual support.
I highly recommend prioritizing communications in a grid down situation. It will increase your survival percentages, and give you someone to talk to!
And please stock in batteries for ALL of your critical devices (opting for rechargeables as much as possible); or they will become a paperweight when you need them most! Out think them, and you will do just fine on your prepping.