AcuRite 02020 Portable Lightning Detector Black, 2½L x 1W x 2¾H

Great unit, only feature missing is a 'Direct Hit' notification, but by then I guess it's too late.: [

We use this at our off-grid shack in conjunction with a NOAA weather radio. It's a fine replacement for leaving the AM band of the radio on with the sound turned down in that we can see how far away the lightening is and if/when the storm is moving towards or away from us. Makes it safer to work in the field and timber.

Used once so far, hiking outdoors at a mountain lake in NJ. Questionable weather was relatively nearby, and might or might not turn into something. All it got was a little cloudy, no storm formed, however the unit went off during our six hours out there, claiming lightning at various distances, sometimes less than a mile. None of that happened. The unit was in the outside web side pocket of my backpack the whole time, and not near any metal or electronic like a cell or other battery carrying device. While this false positive kept happening, I didn't mind it, because there was atmospheric instability in the general area. Storms have to start somewhere, and often do at very high altitudes first, then make their way down to the ground. I figure the first actual strike and heard thunder is always a little surprising - tipping you that ok, something is beginning or happening within earshot, and maybe eyeshot soon. It gets you to consider where you are outdoors and your options for cover, continuing on, turning back, etc.The other thing about this unit is to add to the already stated comment that it often goes into a stuck mode, wanting you to move to another position. I have no idea why this happens, but I thought it would not be bothersome to us on our hike because we were almost always on the move. (The manufacturer claims it often happens when the unit is left sitting still for a long time.) But, like other users, I decided the easiest way to deal quickly and most conveniently was to simply power the unit off and after a couple-three seconds, power it back on again. Sure, you'll lose its count of lightning strikes, but do we really care about that number?So, all in all, the unit is compact, has a display that tells you what you need to know, runs a long time on the pair of AAA batteries, has a good audible alarm, and is half the cost of the more precise unit. I had one of these for about five years until it went batty and wouldn't work right. It was the one that looks like an old-style pager, with little LEDs that also tell you the lightning is getting closer or moving farther away. It was and still is around $75, and has much less false positives, and never wants you to relocate, but it was harder to interpret and turn on and off. So, for the money and the important features, I recommend the AcuRite 02020. I have no idea how long this little guy will perform for me, but next week I go on a total wilderness boat and camp trip, and will use this detector on any chance there's instability and even the slightest chance of bad weather up there. Anyone spending time away from shelter really ought to carry one of these things!-------------------------------------------------------------------------------Additional feedback after a full season of use, and with potential for t-storms in the surrounding area....... The unit does lock up as some have noted. Just shut it down and restart it and it's fine. I wish it didn't do this, because the effect is that if you went entirely on what this unit is telling you, and not observing the skies, you'd think the situation was worse than it actually is. I take this as not such a bad thing however..... Think about this for a minute. Wouldn't you want your attention drawn to the weather instead of getting focused on something on the ground, and then not noticing a developing issue that you might have needed to act on 30 minutes earlier? A perfect example is hiking uphill in rocky terrain, or being out on a lake fishing. It's easy to simply relax and enjoy, but experience has shown us time and again that vigilance is needed all the time, as much as you wish you could simply fully relax about being outdoors.So, I've decided that I like the unit, and will continue to use it, and deal with it's quirkiness. I know that it will always keep me observant of the skies. After all, isn't that all we want it to do? And I should add that once it does lock onto an approaching storm, it does a very good job of letting you know about it, and what you need to know. the rest is up to you, and generally falls easily under the category of "Do the right thing."

After about a year it keeps telling me to relocate it outside and I can hear thunder.

after reading the reviews months ago i decided this unit wasnt worth a 60 dollar risk. too many complaints about non working units, doa etc.imagine my suprise seeing these for just over 20 bucks on some type of Amazon sale discount. ill take 2 figuring even if one was doa/defective i could just return the other.ive had them for several days now, both with standard AAA batteries. they have been on the entire time and stationed about 20 feet apart.we havent had any major storms BUT we have had heat lightning almost every night. Checking the aviation METARS has noted some TS within 50 miles.both have shown cloud to cloud and cloud to ground lightning within 20 or less miles with whatni consider reasonable accuracy for a handheld unit (about 80% of strikes noted showed up on the units) consider this is a small unit that depends on proper placement and no RFI or EFI nearby.the one pictured is mere inches from a 32 inch pc monitor and another 3 within 2 feet. they do not interfere at all. and it actually registered more than the other unit which was on a south facing windowsill.1) use good batteries. dollar store junk wont provide stable power. you dont need alkaline, but name brand quality cells or rechargeable NiMh ones will provide days of use.2) put the unit where you want it prior to activating. ive found that activating it in my hand and then setting it down will reault in the dreaded "change location" but if i set it down, even right in front of a pc monitor and turn it on itll work fine.Ive found these units to be far more accurate than the android/ios apps or any website, even the lightning strike website wont show the strikes for up to a couple hours after. these are instantaneous.for camping ham or broadcast radio antenna farms, linesmen etc these are good units to possibly save your life or equipment.The alerts are loud enough to be heard 20 feet away. the beep is loud but not intrusively so. youll know it when you hear it. the display will light, youll hear some beeps and the strike distance and quantity will pop on the screen... this unit cumulatively counts strikes so if you leave it on for a day or more it will keep counting non stop possibly thru dozens of storms. so if you want per storm data you should turn it off and back on to reset it prior to new data acquisition.5 stars for what they are and what they do at this price @ 24 dollars.

This the perfect tool for any one who likes outdoor activities. If you are out riding your bike and hear thunder, this tool will help you decide whether to turn around and sprint for home.