Why do cheap digital calipers deplete batteries even when off?

[Jeroen3]

The analog caliper has never let me down yet. I would only consider a digital one if I was to measure things a lot.
Basically, when measuring is all you do for hours.

What other advantages does the digital caliper offer that you must have a digital one?

[glarsson]

What other advantages does the digital caliper offer that you must have a digital one?

You can set your own 0. Either to measure relative distances or as a target (set 0 on some template or standard). On the traditional analog your 0 is always the closed position.

[CJay]

What other advantages does the digital caliper offer that you must have a digital one?

You can set your own 0. Either to measure relative distances or as a target (set 0 on some template or standard). On the traditional analog your 0 is always the closed position.

Serial capture as well which could be useful (though I've never used it)

[KL27x]

Fewer moving parts? I feel like a digital caliper can be made pretty crappy and take a lot of abuse and still work fine. Dropping them on concrete, the glass doesn't stick out as much? Although I have cracked the glass on a digital. It's easy to do, if you use calipers in conjunction with power tools or whatnot that vibrate, and you get lost in the project. When the earplugs are in and you're doing w/e, things vibrate off the edge of the bench all the time. When you're done not cutting your finger off, you look over, and sometimes it was your caliper.

Some of the low cost digital calipers eat batteries because of the plastic case that comes with them. The foam in the lid presses on the on/off button and can turn the caliper on when you close the lid.

It doesn't matter the on/off button, specifically. If it pressed any of the buttons, this would greatly increase the drain due to the current through the pullup resistor.

For me, the cases go in the trash. The tool is so much better when it's easy to access and is disposably cheap, anyway. For me, calipers are tools that are quite often used in conjunction with other tools; measuring things accurately is rarely the end goal. My garage shop calipers are stored in custom mounts right where they are used. Instead of carrying a pair of calipers back and forth, and having to retrieve them when they're "over there," I have one at both benches. My electronic bench calipers have no mount, but they also have first order accessibility. If I ever needed a proper case for say travel, I will buy another one for $10.00, and maybe keep the case. The existing calipers will stay where they are.

 

[Electro Detective]

Some of the low cost digital calipers eat batteries because of the plastic case that comes with them.
The foam in the lid presses on the on/off button and can turn the caliper on when you close the lid.

I removed the foam in the lid in the area of the on/off button. That took care of the problem.

I tried that too, on two different branded ones purchased years aoart,
removed only the plastic case foam section around the display and buttons = made no difference, cheap or expensive battery still goes flat 

Even when left out of the case, switched OFF and undisturbed, battery goes flat

There must be a standby/memory/zero function type constant drain somewhere 

 ... easily 'hacked' by removing the battery, lol   

[coppercone2]

My Mitutoyo calipers last a VERY long time. The entry level Fowlers seem to eat batteries like candy. The higher end Fowler devices are considerably better. My Fowler digital 1/10000 dial indicator goes many years.

It does take some engineering effort to keep standby current extremely low. If the product is cheap, the engineering and premium parts are not in the budget.

Short and misplld from my mobile......

I got old slyvacks and the battery is like 1 year 

[Bassman59]

Some of the low cost digital calipers eat batteries because of the plastic case that comes with them. The foam in the lid presses on the on/off button and can turn the caliper on when you close the lid.

I removed the foam in the lid in the area of the on/off button. That took care of the problem.

Huh, I should try that. X-acto knife to the rescue. Also, I should cut some holes in the foam for spare batteries.

[MacMeter]

If one had the time, make it really turn OFF:

https://youtu.be/GcoUdIjZozY

[Erwin Ried]

I added a small switch (those on/off clicky switches)




Already 1 year with the same LR44

[JohanH]

Necrobump, but I also had enough with one of my old calipers that I never use, because battery is always drained.

Added a small switch. Fast and no modification to the caliper itself.

Details:
https://baldpenguin.blogspot.com/2023/05/diy-caliper-on-off-switch.html

[RoGeorge]

They usually don't deplete the battery.  I have had one that depletes a new battery in a couple of months, while sitting unused.  Bought from Bricostore, IIRC.  Bad design, or bad lot of calipers, IDK.

The one I have now (from LIDL) doesn't discharge much the battery.  Has the same battery from 3+ years ago and still working OK (rarely used).

[MacMeter]

I eventually bought a real Mitutoyo, problem solved.

[shapirus]

I had no idea I needed a new digital calipers before I opened this thread .

[RoGeorge]

I kept my first faulty one for a couple of years.  After changing the battery a few times I've ended up removing the battery after each use, but it was used so rare that it doesn't bother me much.

Maybe add a mechanical micro switch to disconnect the battery.

[amyk]

If they can make "solar powered" calculators, why can't the make "solar powered" digital calipers?

Almost 5 years later, but they do exist and there's even the cheap Chinese versions at the usual sites --- although I don't know if they're real or just have a fake solar cell and a battery. Personally I prefer mechanical dial calipers.

[Electro Fan]

Somewhat off topic but....
iGaging IP54 Electronic Digital Caliper 0-6" Display Inch/Metric/Fractions Stainless Steel Body
Claimed Specs:  Accuracy: 0.001" Repeatability: 0.0005" Resolution: 0.0005"/0.01mm/1/128"

I leave the batteries installed until the batteries run low, use the tool occasionally (~monthly for several hours?), might need to change the batteries ~yearly or less often

- Search on Amazon.  $29.95
- One of my most favorite tools (also makes a great gift).  If you need a Mitutoyo you need a Mitutoyo, but the iGaging IP54 is plenty accurate for anything I've ever needed.  I'm pretty sure I could buy batteries for the rest of my life and have saved $ vs a Mitutoyo.

Edit:  almost forgot the most relevant info for the OP - it has Auto Off

[thm_w]

Somewhat off topic but....
iGaging IP54 Electronic Digital Caliper 0-6" Display Inch/Metric/Fractions Stainless Steel Body
Claimed Specs:  Accuracy: 0.001" Repeatability: 0.0005" Resolution: 0.0005"/0.01mm/1/128"

I leave the batteries installed until the batteries run low, use the tool occasionally (~monthly for several hours?), might need to change the batteries ~yearly or less often

- Search on Amazon.  $29.95
- One of my most favorite tools (also makes a great gift).  If you need a Mitutoyo you need a Mitutoyo, but the iGaging IP54 is plenty accurate for anything I've ever needed.  I'm pretty sure I could buy batteries for the rest of my life and have saved $ vs a Mitutoyo.

Edit:  almost forgot the most relevant info for the OP - it has Auto Off

Yeah I recommend igaging in the related thread: https://www.eevblog.com/forum/mechanical-engineering/how-to-spot-fake-mitutoyo-calipers/
CR2032 > SR44. CR2032 is everywhere and easy to get quality cells for a low price.

[G7PSK]

Either get the ones which take lithium coin cells, which do not cost that much more than the ones taking LR4 cells. Or even better get proper Vernier callipers that require no batteries at all, I always use Vernier's with the lathe as suds always get into digital ones even the most expensive, not hard to learn how to use them.