Stud Finders and Batteries (9-volt vs AA)

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roamingzebra
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Stud Finders and Batteries (9-volt vs AA)

Post by roamingzebra »

I'm using an old Zircon StudSensor which is unreliable. The LED lights either go crazy or they don't light up at all. Only rarely can I get the unit to work. After some research, it appears a new 9-volt battery must be used practically every time in order to ensure the unit works correctly.

As a result, I plan to start using magnetic stud finders instead.

However, I notice in earlier Boglehead reviews, there is a recommended stud finder by Franklin that uses AA batteries. I'm wondering if units that use AA batteries are more reliable than the ones that use 9-volt batteries.

In particular, to use one of the Franklin units, is it necessary to install new AA batteries every time the unit is used, especially if the unit has been in storage for a while?

Thanks.
prd1982
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by prd1982 »

It sounds like your current device isn’t turning (or turned) off when not being used. My finder requires you to hold in the sides to activate it.
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MP123
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by MP123 »

I have one of those 9v yellow ones about 10 years old still with the original battery. Very seldom used but it still works fine.

If yours is draining a 9 volt battery regularly it must be staying on somehow or maybe defective. In my experience there is no need to replace batteries before each use, certainly not if it's only been a year or two since last used.
123
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by 123 »

roamingzebra wrote: Sun May 22, 2022 3:52 pm ... After some research, it appears a new 9-volt battery must be used practically every time in order to ensure the unit works correctly...
Maybe you need to remove the battery when not in use. I agree that is not very convenient.
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runninginvestor
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by runninginvestor »

I have a magnet on a string. I'm a cheap millennial.

Although I did try downloading an app on my phone, I figured if there's a magnometer in there I should be able to use it. It was decently accurate, but I can't remember what the app was and I deleted it fairly quickly because I don't like having rogue apps on my phone. In case you wanted an alternate solution.

Edit: I can confirm that you can still point the phone with the stud finder to yourself and make it beep and then say "looks like it works". Ultimate dad joke.
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roamingzebra
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by roamingzebra »

prd1982 wrote: Sun May 22, 2022 4:23 pm It sounds like your current device isn’t turning (or turned) off when not being used. My finder requires you to hold in the sides to activate it.
Mine requires holding in the sides as well. I assume that when I stop, the unit is off, but there's no way of verifying.
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roamingzebra
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by roamingzebra »

MP123 wrote: Sun May 22, 2022 4:40 pm I have one of those 9v yellow ones about 10 years old still with the original battery. Very seldom used but it still works fine.

If yours is draining a 9 volt battery regularly it must be staying on somehow or maybe defective. In my experience there is no need to replace batteries before each use, certainly not if it's only been a year or two since last used.
Mine is a cheap black one. Actually it's not mine, it's borrowed, but...

I found out about the battery problems thru trial and error, later confirmed by some Amazon reviews. I guess the company got tired of the complaints so on at least one model they added a warning:
A new, fully charged 9V battery is required to steadily power the integrated LCD screen in Zircon tools. Please note that, like a cell phone or any personal electronic device, the 9V batteries needed to power Zircon tools can lose power even when sitting idle. The installation of a fresh battery, with an extended expiration date, typically resolves 99% of problems seen by Zircon
Not the same as saying install a new battery before each and every use, but it does hint at the problems some of us are having.

Anyway, since I rarely use 9V batteries, any that I keep on hand as spares will likely have drained by the time I get around to using them, so not really convenient.

And the battery compartment on this model is hell to open. Really bad ergonomics!
bradinsky
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by bradinsky »

Bought this on Amazon a few months back to replace an old, erratic one. I’m not a contractor, but it works fine for home use.
CRAFTSMAN Stud Finder, 3/4-Inch Depth (CMHT77633)
barnaclebob
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by barnaclebob »

Use your knuckle, no batteries needed.
OnceARunner
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by OnceARunner »

I just use a regular old magnet and find the nails in the stud with it.
bob60014
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by bob60014 »

I have a older Zircon that's 10 yo +/- and found that at times, when releasing the side button the indicator would turn off but the button would remain in a locked position, draining the battery. Once I figured it out Ive had no issues with the battery draining.
Mr. Rumples
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by Mr. Rumples »

My house has "plasterboard" where I still have the original walls. This is not gypsum drywall, but plaster 1" thick between the paper. Stud finders don't work well with them.
"History is the memory of time, the life of the dead and the happiness of the living." Captain John Smith 1580-1631
5280Tim
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by 5280Tim »

roamingzebra wrote: Sun May 22, 2022 3:52 pm I'm using an old Zircon StudSensor which is unreliable. The LED lights either go crazy or they don't light up at all. Only rarely can I get the unit to work. After some research, it appears a new 9-volt battery must be used practically every time in order to ensure the unit works correctly.

As a result, I plan to start using magnetic stud finders instead.

However, I notice in earlier Boglehead reviews, there is a recommended stud finder by Franklin that uses AA batteries. I'm wondering if units that use AA batteries are more reliable than the ones that use 9-volt batteries.

In particular, to use one of the Franklin units, is it necessary to install new AA batteries every time the unit is used, especially if the unit has been in storage for a while?

Thanks.
Get the Franklin. No battery issues and it is so much more reliable than any other stud finder I’ve ever used.
fulltilt
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by fulltilt »

runninginvestor wrote: Sun May 22, 2022 4:46 pm I have a magnet on a string. I'm a cheap millennial.

Although I did try downloading an app on my phone, I figured if there's a magnometer in there I should be able to use it. It was decently accurate, but I can't remember what the app was and I deleted it fairly quickly because I don't like having rogue apps on my phone. In case you wanted an alternate solution.

Edit: I can confirm that you can still point the phone with the stud finder to yourself and make it beep and then say "looks like it works". Ultimate dad joke.
A neodymium magnet from a hard drive works great.

I can confirm you can rub it on your body shouting, "BEEP BEEP BEEP BEEP BEEP!!!!!"
Walk a single path, becoming neither cocky with victory nor broken with defeat, without forgetting caution when all is quiet or becoming frightened when danger threatens. -- Jigoro Kano
iamlucky13
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by iamlucky13 »

roamingzebra wrote: Sun May 22, 2022 3:52 pmAfter some research, it appears a new 9-volt battery must be used practically every time in order to ensure the unit works correctly.
....
In particular, to use one of the Franklin units, is it necessary to install new AA batteries every time the unit is used, especially if the unit has been in storage for a while?
This is not inherently a characteristic of the type of stud finder. It sounds like something is wrong with your Zircon unit.

You could try cleaning the the battery holder with rubbing alcohol, just in case there is some contamination on there that is allowing some current leakage.

Alternatively, if you're using a zinc-carbon / zinc-chloride or "heavy duty" battery, that could also be the problem. The "heavy duty" labeling has been outdated ever since alkaline batteries became easily available ~50 years ago. Their shelf life is significantly shorter than alkalines, and their ability to maintain their voltage under load is far worse. While under low load, a zinc-chloride battery might have a useful capacity around half that of an alkaline battery, under even moderate loads, it can easily be less than 10% of the useful capacity.

So check what battery you have in it. If it is labeled heavy duty, zinc, or LeClanche, try replacing it with an alkaline. If you're feeling rich, you could go with one of the Energizer Ultimate or Ultralife brand disposable lithium batteries. These will outperform even alkalines, although the main benefit for this kind of use is they are far, far less likely to leak and damage your device.

I'm pretty sure the stud finder I have is a Zircon. It is at least a decade old, and I don't think I have ever replaced the battery...maybe once at most. I use it a couple times a year, and was using it very regularly when I was installing new trim, but most of the use time has actually been my kids playing with it because they like the flashing lights and beeping.

Regarding magnetic stud finders - I assume the functionality is based on locating fasteners. I've done this with neodymium magnets before, but I usually stick with the density type electronic stud-finder because I'm not dependent on the nail spacing and I can usually find the edges to have a better idea of the limits.

As far as dad jokes...
https://xkcd.com/952/
whomever
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by whomever »

1)You can get rechargeable 9V batteries. Search amazon for '9V low self discharge'.

2)I have a stable of stud finders I rarely use. Instead I have a one inch diameter disk magnet and several 1/4 diameter ones. You 'scan' with the one inch one. When you have localized a screw, put a 1/4 magnet on it (the 1 inch one, oddly, doesn't always seem to center on the screw). Repeat for several screws in the stud. Having multiple screws marked lets you eyeball the center of the stud. Way faster and more accurate, IMHE.
Topic Author
roamingzebra
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by roamingzebra »

fulltilt wrote: Mon May 23, 2022 9:21 am A neodymium magnet from a hard drive works great.
I recently trashed an old PC and only later found a YouTube video saying that the harvesting of magnets was a thing. It showed how to do it. Wish I'd known that earlier, but there are dedicated stud finders with magnets that are cheap enough.

I'm beginning to think the unit I've been using is defective, and in addition to the magnetic one, I might buy try one of the yellow Zircons. If only to establish the edges of the studs since the magnetic ones only find the center (assuming the fasteners were placed in the center). Depending on price, I'll have a look at rechargeable 9V batteries as well. A Franklin unit sounds great but is a little pricey for the limited use I would give it.
iamlucky13
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by iamlucky13 »

This thread made me curious, so I did some quick measurements on my stud finder, a Zircon e50.

I wrote on the battery that I installed it in April of 2017. It's a Radio Shack alkaline, currently at 8.95V, which means it is mostly full (~90%). It has been used multiple times per year in the 5 years since that battery was installed, plus the kids like to play with it periodically, and run around the house making it beep at everything they can until they get bored.

- When on and not over a stud, it was drawing about 10mA steadily, except a brief turn-on spike to maybe 20 mA (too brief to be certain).
- When on and signalling it had found a stud (beeping and light -up indicator), it was drawing 22mA.
- I did not test the deep scan feature or live wire detection.

Since a 9V alkaline battery has 500-600 mAh of capacity, it could theoretically last 2 days of continuous on time while searching.

Also, I retract what I said above - even a "heavy duty" battery would be able to power this stud finder without issue except the shorter shelf life. I was expecting something like 100mA, not 10mA.
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roamingzebra
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by roamingzebra »

Update: Some DIY projects are easy. Some are perplexing. This is one of them.

All I'm trying to do is find a couple of studs so as to install a grab bar in a parent's bathroom. I started by ordering the magnetic stud finders and found that guess what?... there are no studs in the wall. :)

However, the stud finder revealed that there are full-length magnetic metal strips/structural members at corners where walls intersect. Just no isolated spots that would indicate studs.

Trying to find what the problem is, I discovered the following:

Some fasteners are not magnetic. I tested various nails and screws I had on hand and while all the nails were magnetic, not all of the screws were.

Exhibit A: there is an existing grab bar in another bathroom and none of the screws used to fasten it to the wall are magnetic. As for the wall itself, the magnetic stud finder indicated no fasteners behind the wall anywhere near the grab bar let alone on the entire wall. Yet I know this grab bar was installed by a reputable handyman (years ago) who would know to install grab bars on studs.

I guess the question that immediately jumps out is: Are most stud fasteners screws? If they are, and the homebuilder used non-magnetic screws, that would explain what I was seeing.

Otherwise, I'll just chalk this up to a mystery and move on to the other type of stud finder.
Chuckles960
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by Chuckles960 »

fulltilt wrote: Mon May 23, 2022 9:21 am
runninginvestor wrote: Sun May 22, 2022 4:46 pm I have a magnet on a string. I'm a cheap millennial...
A neodymium magnet from a hard drive works great.

I can confirm you can rub it on your body shouting, "BEEP BEEP BEEP BEEP BEEP!!!!!"
I tried the Nd magnet, and it sticks to my upper arm where I had the Covid shot. Especially in hot and humid weather. Should I investigate this? Could there be a stud hiding in there? (My wife says no, but what does she know.)
PGR
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by PGR »

roamingzebra wrote: Sun May 22, 2022 3:52 pm I'm using an old Zircon StudSensor which is unreliable. ...
I had 2 different Zircons many years ago - neither could find the broad side of a barn - frustrating junk!

I switched to a powerful magnet sensor and never looked back - it finds drywall screws or nails and from that I can quickly tell where the studs are. And no batteries.

Once in a while if I need to know a precise edge(s) of a stud I will push a thin clothes pin thru the drywall and see if I hit air or stud - it's so small it won't leave a hole I have to worry about.
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by crefwatch »

A better grab bar screw for a wet environment could be stainless steel or aluminum. I don't build houses, but at best, bathroom wallboard would be secured with galvanized steel, not stainless screws.

Did you notice in the thread that some people have a stable of stud finders? You need to try another one. I have at least four. Have you seen the sheet steel drywall "corner" strips at Home Depot?

Last resort, make an inspection hole and then patch it.
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roamingzebra
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Re: Stud Finders and Batteries (9-volt vs AA)

Post by roamingzebra »

crefwatch wrote: Fri May 27, 2022 6:10 am Have you seen the sheet steel drywall "corner" strips at Home Depot?
Thanks. The drywall corner strips seem to be what I'm picking up with the magnetic stud sensors.

I did some more reading about Zircon and it appears (besides a lot of bad reviews) that rechargeable 9-volt batteries are not an option.

I also saw a video which describes why so many people have trouble with stud finders. For example, if you calibrate it on the wall, then move your hand position ever so slightly, that can totally negate the calibration. I ran into all the "mistakes" documented, but that was not the ultimate problem. The problem seems to be a defective unit, possibly with the culprit being that once the on/off button is pressed, it can't be reversed and so stays on and drains the battery.

In my limited research, so far it seems the expensive Franklin unit has the least reported problems. The lower-end Franklins do have some complaints of unreliability and I always feel better when an entire product line is known for reliability, but whatever.

I think I'm going to pause a little and try to go through my mother's healthcare to get the grab bar installed. If that doesn't work, I'll consider the high-end Franklin unit and maybe use that as an excuse to mount a TV screen on the wall. :)
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