Digital Calipers That Don't Drain the Battery

On 11/12/2022 5:58, Ricky wrote:
> On Friday, November 11, 2022 at 7:21:45 PM UTC-4, Dimiter Popoff wrote:
>> On 11/11/2022 23:42, Ricky wrote:
>>> On Friday, November 11, 2022 at 1:03:14 PM UTC-4, Martin Brown wrote:
>>>> On 11/11/2022 15:40, Ricky wrote:
>>>>> I, like many others, have digital calipers that drain the battery while sitting, and have no on/off switch, so the battery must be removed when not being used. I recall a conversation here some time ago about this and some had found different brands that worked better than others, in this regard.
>>>>>
>>>>> Anyone recall the names of the brands that don't drain the battery?
>>>> The ones with an on/off switch!
>>>> Actually mine just has an on switch and times out after a few minutes.
>>>
>>> I suppose I was not clear as to my meaning by "on/off" switch. They typically have a push button to turn on. I've never seen one with a mechanical switch to directly disconnect the battery. Turning them off by the push button seems to only mute the display.
>>>
>> It does turn off the display and likely puts the MCU into deeper sleep.
>> I have one of these, needs a new battery every 3-4 years, cost me
>> something like $10 or $20, don't remember. Is quite accurate, I also
>> have a micrometer (I do have a mechanical workshop, lathe etc. and I
>> am quite experienced doing that sort of thing, too) and they match
>> really well, if you know how to use it you can rely on it all the
>> way down to its 0.01mm resolution.
>> Keeping a blister of cr2032-s has you covered for at least a decade.
>>
>> How long do you expect your battery to work?
> 
> To work?  A few weeks at least.  When off?  Years, or as long as the
> batteries last sitting on the shelf.  I don't know how long they
> actually last.  Every time I put it away without removing the battery
> it is dead the next time I use it.  I don't have a battery at the
> moment, so it's useless.  It uses the smaller battery.  I might have
> a pack of those somewhere, but I don't care.  If I can't find a
> digital caliper that will not run down the battery, I'll just get a
> pair of head mounted lenses and use the dial caliper.

Here is the one I got some 7-8 years ago:
http://tgi-sci.com/misc/caliper.jpg

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.

> 
> I do know better than to ever use a Kirkland (Costco) battery again.
> I had a batch of AAs that ruined a half dozen pieces of equipment.
> Costco wouldn't even refund the purchase price.
> 

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.

On 11/12/2022 4:48 AM, Sylvia Else wrote:
> On 12/11/2022 10:10 am, Ricky wrote:
>> On Friday, November 11, 2022 at 6:27:40 PM UTC-4, Sylvia Else wrote:
>>> On 12/11/2022 9:00 am, Ricky wrote:
>>>> I just thought by now, there might be lower cost units that don't 
>>>> drain the battery. It's a damn simple circuit to implement that. I 
>>>> don't even think it requires a separate part. It's just a p-channel 
>>>> pass transistor with the switch as a bypass. Can't they put that on 
>>>> the chip and bring out a pin for the push button switch to bypass 
>>>> the pfet?
>>>>
>>>> I guess it's a matter of them selling a bazillion of the ones they 
>>>> are making now. Why would they change?
>>>>
>>>> But once one of the low cost devices starts bragging about not 
>>>> draining the battery, they will all have to switch. It doesn't take 
>>>> much sales pressure when you are only making a few cents per device.
>>>>
>>> Yes. The actual circuitry required is really simple. I think it's not
>>> included because if the thing is powered down, it loses its zero
>>> position (there are more advanced designs that have absolute
>>> positioning, but they probably cost more to make).
>>>
>>> So it may come down to that. People would notice the loss of zero and
>>> complain before they realise that the batteries run down quickly.
>>>
>>> For me, I'd probably zero it out of habit when I turn it on and not even
>>> notice the loss, but perhaps people differ.
>>
>> Like you, I always auto zero calipers, including the dial variety if 
>> I'm trying to make a good measurement.  It's hard to think anyone 
>> would expect zero to not drift, but many people don't understand 
>> electronics and seem to think digital is supposed
> to be as accurate as the display can indicate.   That is seldom true.
>>
> You mean like
> 
> https://www.dropbox.com/s/ofdf2ekw1104awn/T_temperature1.jpg?dl=0
> 
> Sylvia.


They're all correct. It's fuzzy temperature.
-- 
Dogs make me happy. Humans make my head hurt.

On Saturday, November 12, 2022 at 3:22:03 PM UTC-4, Bertrand Sindri wrote:
> Ricky <gnuarm.del...@gmail.com> wrote: 
> > On Saturday, November 12, 2022 at 1:02:46 PM UTC-4, legg wrote: 
> >> On Fri, 11 Nov 2022 07:40:06 -0800 (PST), Ricky 
> >> <gnuarm.del...@gmail.com> wrote: 
> >> > I, like many others, have digital calipers that drain the battery 
> >> > while sitting, and have no on/off switch, so the battery must be 
> >> > removed when not being used. I recall a conversation here some 
> >> > time ago about this and some had found different brands that 
> >> > worked better than others, in this regard. 
> >> > 
> >> >Anyone recall the names of the brands that don't drain the battery? 
> 
> >> Two sets here in two tool boxes. I keep a spare battery in their 
> >> cases - expect to have to change at least annually. If you only 
> >> pick them up once, every year or two, then dead batteries will be 
> >> no surprise. 
> > 
> > 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?
> 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". 

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.  


> 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). 

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


> 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'.

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


> > This is clearly bad product design.
> 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.

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. 

-- 

Rick C.

-++ Get 1,000 miles of free Supercharging
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søndag den 13. november 2022 kl. 00.37.37 UTC+1 skrev Ricky:
> On Saturday, November 12, 2022 at 3:22:03 PM UTC-4, Bertrand Sindri wrote: 
> > Ricky <gnuarm.del...@gmail.com> wrote: 
> > > On Saturday, November 12, 2022 at 1:02:46 PM UTC-4, legg wrote: 
> > >> On Fri, 11 Nov 2022 07:40:06 -0800 (PST), Ricky 
> > >> <gnuarm.del...@gmail.com> wrote: 
> > >> > I, like many others, have digital calipers that drain the battery 
> > >> > while sitting, and have no on/off switch, so the battery must be 
> > >> > removed when not being used. I recall a conversation here some 
> > >> > time ago about this and some had found different brands that 
> > >> > worked better than others, in this regard. 
> > >> > 
> > >> >Anyone recall the names of the brands that don't drain the battery? 
> > 
> > >> Two sets here in two tool boxes. I keep a spare battery in their 
> > >> cases - expect to have to change at least annually. If you only 
> > >> pick them up once, every year or two, then dead batteries will be 
> > >> no surprise. 
> > > 
> > > 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? 
> > 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".
> 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.

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

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

> 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 

That's when it is turned off. While operating, measurements showed current 
fluctuating between 2uA and 6uA.



-- 
MRM

On Saturday, November 12, 2022 at 8:48:21 PM UTC-4, lang...@fonz.dk wrote:
> søndag den 13. november 2022 kl. 00.37.37 UTC+1 skrev Ricky: 
> > On Saturday, November 12, 2022 at 3:22:03 PM UTC-4, Bertrand Sindri wrote: 
> > > Ricky <gnuarm.del...@gmail.com> wrote: 
> > > > On Saturday, November 12, 2022 at 1:02:46 PM UTC-4, legg wrote: 
> > > >> On Fri, 11 Nov 2022 07:40:06 -0800 (PST), Ricky 
> > > >> <gnuarm.del...@gmail.com> wrote: 
> > > >> > I, like many others, have digital calipers that drain the battery 
> > > >> > while sitting, and have no on/off switch, so the battery must be 
> > > >> > removed when not being used. I recall a conversation here some 
> > > >> > time ago about this and some had found different brands that 
> > > >> > worked better than others, in this regard. 
> > > >> > 
> > > >> >Anyone recall the names of the brands that don't drain the battery? 
> > > 
> > > >> Two sets here in two tool boxes. I keep a spare battery in their 
> > > >> cases - expect to have to change at least annually. If you only 
> > > >> pick them up once, every year or two, then dead batteries will be 
> > > >> no surprise. 
> > > > 
> > > > 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? 
> > > 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". 
> > 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.
> 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?  

-- 

Rick C.

+-- Get 1,000 miles of free Supercharging
+-- Tesla referral code - https://ts.la/richard11209

Ricky <gnuarm.deletethisbit@gmail.com> wrote:
> On Saturday, November 12, 2022 at 3:22:03 PM UTC-4, Bertrand Sindri wrote:
>> Ricky <gnuarm.del...@gmail.com> wrote: 
>> > 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?

>> 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".
> 
> 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.

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

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

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.

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

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

>> > This is clearly bad product design.

>> 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.
> 
> 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.

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.

On Saturday, November 12, 2022 at 10:42:37 PM UTC-4, Bertrand Sindri wrote:
> Ricky <gnuarm.del...@gmail.com> wrote: 
> > On Saturday, November 12, 2022 at 3:22:03 PM UTC-4, Bertrand Sindri wrote: 
> >> Ricky <gnuarm.del...@gmail.com> wrote: 
> >> > 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? 
> 
> >> 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". 
> > 
> > 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.
> A caliper with no battery never needs a battery in order to be 
> operational.
> >> 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). 
> > 
> > Please don't offer advice when you don't know the facts.
> 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.
> >> 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'. 
> > 
> > Or buy a device that isn't made from crapolleum.
> I.e., the very definition of what I said in: "better quality caliper". 
> Is your reading comprehension lagging?
> >> > This is clearly bad product design. 
> 
> >> 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. 
> > 
> > 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.
> 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. 

-- 

Rick C.

+-+ Get 1,000 miles of free Supercharging
+-+ Tesla referral code - https://ts.la/richard11209 

On 11/11/2022 21:42, Ricky wrote:
> On Friday, November 11, 2022 at 1:03:14 PM UTC-4, Martin Brown
> wrote:
>> On 11/11/2022 15:40, Ricky wrote:
>>> I, like many others, have digital calipers that drain the battery
>>> while sitting, and have no on/off switch, so the battery must be
>>> removed when not being used. I recall a conversation here some
>>> time ago about this and some had found different brands that
>>> worked better than others, in this regard.
>>> 
>>> Anyone recall the names of the brands that don't drain the
>>> battery?
>> The ones with an on/off switch! Actually mine just has an on switch
>> and times out after a few minutes.
> 
> I suppose I was not clear as to my meaning by "on/off" switch.  They
> typically have a push button to turn on.  I've never seen one with a
> mechanical switch to directly disconnect the battery.  Turning them
> off by the push button seems to only mute the display.

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

-- 
Regards,
Martin Brown

On 2022-11-12 18:36, Ricky wrote:
> On Saturday, November 12, 2022 at 1:02:46 PM UTC-4, legg wrote:
>> On Fri, 11 Nov 2022 07:40:06 -0800 (PST), Ricky
>> <gnuarm.del...@gmail.com> wrote:
>>> I, like many others, have digital calipers that drain the battery while sitting, and have no on/off switch, so the battery must be removed when not being used. I recall a conversation here some time ago about this and some had found different brands that worked better than others, in this regard.
>>>
>>> Anyone recall the names of the brands that don't drain the battery?
>> Two sets here in two tool boxes. I keep a spare battery in their
>> cases - expect to have to change at least annually. If you only
>> pick them up once, every year or two, then dead batteries will be
>> no surprise.
> 
> 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.
> 

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.

-- 
Cheers, Carlos.