Digital calipers and battery life

[Reentrant]

I recently bought a 6" digital caliper off eBay (about £7, probably identical to the Aldi one at a similar price or two-three times that from the usual suspects).

I just happened to find this link c/o the Wikipedia page

- which says the battery is always in use (the "off" button just turns off the display) and a regular LR44 will be drained in less than a year. That explains all those Amazon purchasers' comments that the battery was DOA.

So if you only use it rarely - which is likely if you bought a cheap Chinese one - you might want to take the battery out during storage.

[gareth]

Sound advice, but because you'll forget where you put the battery for safe-keeping, slip a piece of paper in over one end of the battery.

(Things like TV controllers come like that; yo have to whip out the tab in order to put into use)

[Martin Brown]

I'd say dead in about 2 or 3 years which is not that far off the shelf life of an LR44A battery. I find that LR44s that are past it for driving my laser level are fine in the low current digital micrometer. I keep a stock of no longer up to high current batteries.

Where upon you lose it and have to buy a new one. I suspect when "off" it still powers the parts needed to detect the "on/off" button being pressed but I have never bothered to investigate in detail. Suffice to say that the battery lasts well enough. Interestingly on low battery it comes on spontaneously resets and comes on again flashing the display but never quite gets initialised. After a while it expires completely.

The salt off your fingers from handling the small battery can also significantly shorten battery life so if you care about longevity polish it with a soft cloth or don't bridge the poles when handling it.

[docholliday93]

I had deduced that only the display was switched off from the fact that on my more recent calipers measurement continues even while switched off, i.e. if you open the jaws and then switch on you still get a measurement, where as my old pair displays zero on switch on whatever position the caliper is in. The corollary from that is that if you remove the battery you need to reset the calipers to zero when putting it back. TBH I tend to just accept that the battery needs replacing every couple of years, as the convenience outweighs the relatively small cost.

[Reentrant]

Mine came in a case with nook for the battery - I assume they all did as they all look identical in the pictures.

[newshound]

One of mine came with a badly designed case which actuated the button permanently; fairly easily modified

[Andrew Gabriel]

What does the battery do for you that a vernier caliper doesn't?

[Brian_Gaff]

Normally in transit they have a little plastic thing in between the battery and the contact on one side. Not that I can use one now, but its pretty general on the battery operated gizmos, these days when they ship with batteries inside. Brian

[RobertL]

For those of us whose eyes have seen better days, they are a boon.

Robert

[Dave Plowman (News)]

Easier to read? Can switch between inches and mm?

FWIW I've had a 'battery' one for ages. The battery lasts at least a couple of years. The original may not do if it was connected - as they do draw some current even when switched off. So would depend on when it was fitted.

[whisky-dave]

makes it easier to read .

[Reentrant]

... also you can zero it at any position, which makes it very easy to measure the difference between two objects.

[Roger Mills]

Certainly. Saves squinting at the Vernier lines to try to figure out which ones line up.

Can switch between inches and mm?

Yes, it can - check the conversion! I've got two of the beasts - one from Maplin which is fine, and one from Lidl - which isn't.

The Lidl one is fine on mm but way out on inches - I forget by how much, but it's more than (say) assuming that 1" = 25mm rather than 25.4

Interesting. I've noticed subjectively that my batteries don't seem to last very long - but haven't recorded actual life. In particular, they don't seem to like being in a cold garage in the winter - so I now keep mine in the house.

[Martin Brown]

Mine is an Aldi/Lidl one and its calibration is fine.

A little freebie (and otherwise useful) card I was given at a trade show with a 6cm rule on one side turned out to be 90% short measure. It was quite a while before I noticed...

That is more likely fingerprints and condensation bridging the insulation on the battery itself. Mine lives indoors and only gets fed with batteries that have already failed elsewhere (as do all my low current drain bits and pieces).

[Bob Eager]

Mine has a little battery storage place in the case!

[John Rumm]

Makes it easy to read in most light conditions when you have not got your reading glasses on...

(resisting the options suggestion to get bifocals!)

[John Rumm]

Same here... then again I am working through my stock of crap LR44s that arose out of ordering 5 from CPC not realising they were in packs of a dozen!