Digital Calipers That Don't Drain the Battery (2023 Update)

Think about that for a minute. If I can't expect a battery in an unused device to last a year sitting in the case, why would I expect an extra battery to be good? This is clearly bad product design. End of story.

All my projects are home! I fully retired 4 years ago. Mikek

A disconnected battery will last significantly longer than one that is being actively drained because the 'off' button was interpreted by the Chinese engineer as "turn off the display" instead of as "use as little quiescent current as possible".

How often do you make use of the calipers? Implying that they "sit in the case" for a year between uses means you seldom ever reach for the calipers. In that case, your best course of action is to invest in a nice pair of vernier calipers, invest the small amount of time needed into learning to read the vernier, and then never have to worry about "dead batteries" ever again (because vernier calipers have no batteries).

Otherwise, if you do use them often, then either invest in a supply of fresh batteries, or invest in a better quality caliper that does not drain the battery so fast while 'off'.

Yes, but you can't change the design of the ones you have, all you can do is remove the battery after each use so it is not drained by the always on electronics of the pair you have.

Yes, mitutoyo, Starrett. I own one of each. Battery life for each is many years. IIRC, the batteries last 4-5 years. I use them sporadically, so most of the time they are sitting on the shelf in their box.

Mitutoyo. I get the coolant-proof kind, so an accidental splash does not kill the caliper.

Joe Gwinn

Here is the one I got some 7-8 years ago:

Works just fine as I said before, I have the habit to switch it off (I don't even know if it times out) and the battery lasts for years of sporadic use. Obviously no matter how long it lasts one must have some spare batteries at hand, just like say for the DMM. I got the caliper at a food store, Lidl, like the rest they also sell now all sorts of things. Of course even if you see the same in a shop today it does not mean it will work the same, who knows how many levels of cheapefying it has undergone.

For batteries I discovered (perhaps after someone's post here) the right source was.... IKEA. For AA NiMH and alkaline at least.

For the DMM (a 9V battery) I have been out of events "dead battery in the middle of work" ever since I bought a few NiMH "9V" ones, I keep some charged. They lose plenty of their charge in a year etc. but still have some to let you resume work for the day until you have a freshly charged one.

They're all correct. It's fuzzy temperature.

That doesn't take a year, and I have no use for such a device. That's my point. I'm looking for a device that won't drain the battery, because it actually turns off.

Please don't offer advice when you don't know the facts.

Or buy a device that isn't made from crapolleum.

Ones? At this point I have one that I know of and I don't know where it is. I tossed it in a drawer somewhere and the next time I find it, it will go into the trash.

I guess my previous posts were not so clear on the matter.

a genuine Mitutoyo doesn't really turn off it doesn't need to, it uses so little current it doesn't matter, something like less than a 1 uA it'll last years on a battery

I don't know why you say it doesn't turn off. The oscillator stops running, I'm sure. The LCD is not being driven. The sensors are not being checked. In short, every part of the design is not functioning, and being CMOS, draws infinitely little power. Or, they may have a p-fet in series with the power, either internal to the chip, or external to the chip. None of this matters, because they have effectively stopped the power drain by actually ceasing to operate.

Do you have any info on the actual design?

A caliper with no battery never needs a battery in order to be operational.

The flaw there lies with the person who failed to provide the facts. And in case that suggestion flew over your head, the flaw there lies with you.

I.e., the very definition of what I said in: "better quality caliper". Is your reading comprehension lagging?

Therefore implying you seldom ever use it (because if you used it often it would not be 'lost in a drawer somewhere' to be 'found' at some indeterminate future time). Which means my suggestion of obtaining yourself a caliper that does not use a battery (i.e., a traditional vernier one) is the better option for you.

I know exactly where my 1960's era vernier caliper is located, and while I don't use it often, since it does not use a battery I have no concerns that it will fail to display a reading when I do reach for it.

I'm sorry that you have to troll rather than discuss. I've already ordered a new caliper, so no further need for your excellent advice. Thank you.

Mine seem to last a year or so. LCD display when done in bare metal takes so little power that muting the display is pointless.

I don't see battery life as an issue. YMMV

Apparently, once a battery is "started" it starts slowly losing charge even if you put it again in a box, disconnected. The warranty date is not valid once you start using the battery even once, the chemistry inside changes.

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That is NOT 'apparent'.

References in the literature, please.

RL

it may be "off" but it is still "on" enough to maintain the origin, if you replace the battery you have to set the origin

it may be "off" but it is still "on" enough to maintain the origin, if you replace the battery you have to set the origin

This does happen (battery manufacturers agree) in zinc-air batteries, which are shipped with a sticker blocking air entry. The warranty on a battery is only for its storage discharge rate (and is rather on the conservative side, I've actually measured useful charge in batteries aged 30 years).

Battery manufacturers' literature on actual battery amp-hour capacity has, when I've checked, been accurate.

This would be the Duracell Copper-Top batteries. The problem was that they leaked and ruined expensive items, not just flashlights, causing their sales to crater when word got around. Pretty soon they came out with a "premium" version guaranteed for ten years, now 12 yeses, while "in storage". Probably is the original design with new marketing.

In any event, the bit about the chemical reaction being started by first use is nonsense. Batteries wear out just sitting there, some faster than others.

The bit about the warrantee is a legal issue, not a technical or engineering issue. The problem is that Duracell cannot know what the actual load will be (or was) after installation in a user-provided device, so there is no way to guarantee that aside from the guaranteed capacity, to prevent warrantee abuse.

Joe Gwinn