Battery Amusement - Page 1
Forum section: electronics / general

author: paulca
author_rank: Super Contributor
timestamp: August 22, 2024, 11:40:40 am
content: I have about a dozen battery powered sensors for temperature/humidity.In the spring the kitchen sensor stopped sending data. It's battery was flat.Then in June it sent a single sample, "21.0C" and died again.The office sensor and bedroom sensor are now following suit. They go incognito for days and then on a nice warm day they find enough voltage/residual power to power up and send one sample before dying.The kitchen came back yesterday again, this time for 22.0C.The sensor I put into the fridge worked perfectly until it got down to 4C, when it died after 2 days. However, when I raised the temp i the fridge to 16C it started reading again normally. It read normally a whole week until I "cold crashed the beer" and this time it cut out at 5C.I just find it amusing how coin cells can have "elasticity" and "bounce back" which is temperature dependant over months!Downside is, I need to order even more big fat coin cells and go replacing batteries. They all get replaced at the same time to keep the endevour compressed. To date it's about once every year for the temp/humidity and once every 2 years for motion sensors.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 23, 2024, 06:32:35 pm
content: Good Morning Paulca, I don't have any problems with temperature sensors, but all my humidity sensors go to hell in a matter of a few months, but it is not a battery issue. They just start producing random readings that don't make sense, (my 8th grade English teacher would call it 'Giberish). Not that my issue is in any way related to your problem, but you gave me an opportunity to get it off my chest.Thank you for that.

author: paulca
author_rank: Super Contributor
timestamp: August 23, 2024, 07:54:37 pm
content: Humidity sensors are by their nature prone to humidity. If/when it ever condenses within the sensors it's done for.There are "YMMV" approaches of putting the sensors or the full board -plastic into an oven for a few hours to dry it out. Otherwise, in my experience they don't really survive total saturation very well. If you ever get a situation where the moisture condenses onto the sensor it's game over.More "involved sensors" use different methods and/or heaters.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 24, 2024, 12:06:52 pm
content: You guys use Celsius, not Fahrenheit?Not ranting, genuine question, I thought UK is using mostly imperial units. Or is it that you are using a mixture of both metric and imperial?

author: SteveThackery
author_rank: Super Contributor
timestamp: August 24, 2024, 01:06:20 pm
content: Quote from: RoGeorge on August 24, 2024, 12:06:52 pmOfficially the UK uses metric units for most things, although the government-led drive to fully adopt metric units was abandoned a few decades ago (there used to be a quango called the Metrication Board). Membership of the EU further forced the adoption of metric units, although the UK still uses miles as the official unit for road distances - all the road signs are in miles. Interestingly, the roadside "mile markers" are in kilometres.Official fuel consumption figures from the car manufacturers are always in litres per hundred kilometres, but everyone I know thinks and speaks in miles per gallon.Some people - especially non-techy people - still measure lengths in feet and inches. Fahrenheit seems to have fallen largely out of favour nowadays. Older people still seem to think in ounces, pounds and stones, but not younger people.Most of us buy milk by the pint, but the bottle is labeled in both systems. The one in my fridge says:2.272l <---that is a lower case 'L'4 pintsThe construction industry is weird. You can ask for, and be sold, a length of "four by two" timber, but it will actually be sized in millimetres and will be thinner than 2 inches and narrower than four inches.As far as I know, all our engineering and manufacturing industries are fully metric and have been for decades.This mix sounds like a real mess, but by and large everything works OK. We got some concessions from the EU to keep miles and to allow pricing of foodstuffs in both metric and imperial, although the only people using the latter are the occasional market stall.As a model engineer and clock and watch repairer, I find metric measurements to be very awkward. Many of the things I make require fractions of a millimetre, but usually microns are far too small. It happens that thousandths of an inch ('thou') are an almost perfect unit. Precision to a thou* is sufficient for most engineering purposes (virtually all amateur purposes), and in the world I work it is fairly rare to need dimensions bigger than an inch. So we have a unit - the "thou" - that gives integer values all the way from the limit of precision - '1' - up to the biggest size we will normally need - '999'. Even then it is easy to go bigger: one inch plus however many thou. That is why, when I bought my lathe, I bought one with imperial units, even though I live in a metric country.*All affordable measuring devices, like digital calipers, will resolve measurements to 1 thou - some down to half a thou. But switch them to metric and they typically resolve to 0.02 millimetres, so almost all measurements are an awkward fractional number: 50 thou vs 1.27mm. It makes the mental arithmetic so much easier.

author: coppice
author_rank: Super Contributor
timestamp: August 24, 2024, 01:14:18 pm
content: Quote from: RoGeorge on August 24, 2024, 12:06:52 pmThe UK has a strange relationship with temperature. Cold is measured in Celsius, but many people still measure hot in Fahrenheit. Its a long time since I heard water freezing in winter referenced to as reaching 32. Its always reaching zero. However, for some people 32 is a hot day, but for many a hot day is still 90...... although, being a country that is cold for much of the year, many people think its a hot day if its over 20C.

author: coppice
author_rank: Super Contributor
timestamp: August 24, 2024, 01:16:32 pm
content: Quote from: SteveThackery on August 24, 2024, 01:06:20 pmDidn't milk change to 1l, 2l and 4l bottles when home deliveries stopped, and all milk was bought from a supermarket, and then change back to round numbers of pints?

author: SteveThackery
author_rank: Super Contributor
timestamp: August 24, 2024, 01:37:29 pm
content: Quote from: coppice on August 24, 2024, 01:16:32 pmSorry, I'm not quite sure what you are asking. All milk must be sold in metric units, but it can still be marked up in imperial as well. I think some supermarkets sell milk in "round number" metric units, like 1 litre, 2 litres; other supermarkets sell milk in "round number" pints, with an awkward (but legal) metric measure.You might be right that supermarkets only sold in metric units at one time, and then went over to whole number pints more recently. I can't quite remember, to be honest.

author: SteveThackery
author_rank: Super Contributor
timestamp: August 24, 2024, 01:41:16 pm
content: Oh, I've just remembered: the UK got a concession from the EU for selling beer in pints, but I think this only applies in pubs. Spirits sold in pubs are metric, though. Beer is metric when sold in cans or bottles.

author: coppice
author_rank: Super Contributor
timestamp: August 24, 2024, 02:09:35 pm
content: Quote from: SteveThackery on August 24, 2024, 01:37:29 pmI'm talking about round numbers of litres or pints. Everything else is just a labelling issue.Quote from: SteveThackery on August 24, 2024, 01:37:29 pmIf you buy specialities, like Jersey milk, goats milk, UHT or banana milk, they tend to be in round numbers of litres. I think all the UK supermarkets currently sell full, semi-skimmed and skimmed only in round numbers of pints.

author: Zero999
author_rank: Super Contributor
timestamp: August 24, 2024, 03:45:36 pm
content: Quote from: coppice on August 24, 2024, 01:14:18 pmThat's obviously to make it sound more extreme. It sounds more impressive to say, on "Between 18 and 19 July 2022, the UK experienced an extreme inferno. In many places, the temperature exceeded 104 °F and stayed above 80 °F over night." 40 °C and 26.7 °C, just isn't as attention grabbing.I can understand the reason to switch to decimal units for length, mass etc. but temperature doesn't make things any easier. Both Fahrenheit and Celsius have negative numbers and neither work with SI prefixes. We could move to Kelvin, but it results in big numbers, even for low temperatures: 250 K is still pretty cold.

author: themadhippy
author_rank: Super Contributor
timestamp: August 24, 2024, 03:47:43 pm
content: Quoteunless its sold in a returnable container,then a pint is fine.

author: coppice
author_rank: Super Contributor
timestamp: August 24, 2024, 03:52:26 pm
content: Quote from: Zero999 on August 24, 2024, 03:45:36 pmSo, you think Britain would move to C for low temperatures, and K for high ones?

author: Zero999
author_rank: Super Contributor
timestamp: August 24, 2024, 04:01:39 pm
content: Quote from: coppice on August 24, 2024, 03:52:26 pmThat's already what the likes of the Sun and Daily Mail have done.EDIT: I misread. I thought you said F. Good idea: suggest to the tabloids they use kelvin for hot a centigrade for cold.

author: SteveThackery
author_rank: Super Contributor
timestamp: August 24, 2024, 10:06:39 pm
content: Quote from: coppice on August 24, 2024, 01:14:18 pmActually my experience is a bit different. I haven't heard people using Fahrenheit for either end of the temperature scale for some years now, so I'm going to stick to my original claim.One reason for the demise of Fahrenheit is that all broadcast weather forecasts have been in Celsius for decades.

author: paulca
author_rank: Super Contributor
timestamp: August 25, 2024, 01:58:53 pm
content: Quote from: SteveThackery on August 24, 2024, 01:06:20 pmI got done for speeding. Doing 70mph in a 60mph zone. However. The section of road they did me on was unrestricted dual carriageway. These are 70mph in the UK. I had just overtaken someone when the lanes merged down to one and delayed slamming on the brakes in front of them to get down to 60mph. So I figured they'd got me on the "legal line" between the 70 and the drop to 60.However the "Speed awareness" course I was 'offered' instead of points and a fine (though the course cost £200)... the instructor there when asking everyone where and how they got done, told me that the particular road I was done on was very, very common now, due to new EU "highway classification rules."The EU had recently proposed a regulation that the 120km/h class highways MUST have a concrete or armco safety structure and cannot be meerly grass or dead space. Without concrete dividers or other safe structure (like found on motorways in the UK), they were to be demoted to 100km/h classed highways.So, for a period of time they were doing people for doing 70mph on unrestricted dual carriage way, because the final section of that carriage way had nothing but dead space there.I took speed awareness course, paid my £200 and left it. However when discussing this later with an advanced driving instructor he was adament that it was 70mph. I did some horrible research into government legislation and found the legistlation in the status, "Reviewed and rejected" bin of EU regulations. It never applied here. The UK gov rejected it due to the cost involved in upgrading all the "dual carriage" way routes to have concrete and/or steel safety dividers. Basically up to UK "Motorway class" roads to achieve 70mph.Apparently quite a few people appealed it and got it revoked. I didn't bother in the end.

author: paulca
author_rank: Super Contributor
timestamp: August 25, 2024, 02:06:29 pm
content: Quote from: SteveThackery on August 24, 2024, 01:37:29 pmFunny enough, here the supermarkets (asda, tesco, sainsburries) typically have1 pint; labelled 568ml - 1 pint.1 litre; labelled 1L - 1.87... something pints.2 litre; x pints3 litre; x pintsThe odd one out is the "pint" sized is an actual "pint" of milk and not 500ml.Tobacco sold by "the ounce" is now sound in 12.5g = half ounce. 25g = 1 ounce, 50g 2 ounces etc. "metric ounces". You only really want to be careful of that when buying something really expensive. Those 3g an ounce add up fast.Not a lot of people know this, but copper 1p/2p coins are equivalent to fraction ounces. A penny weighs 1/8th of an ounce 3.5g. 2 pennies weight a quarter of an ounce 7g. If you ever amass any sizeable bag of coppers the bank will trade them (if you are lucky) by putting them on a scale and paying you by the gram equivalent maybe + a fee for handling high volume coin.They are, however, no longer made of pure copper. When the price of copper got close to exceeding the face value of the coin, gypsy sorts started melting them down to billet copper. A criminal offense, but the solution was to make them copper coated steel blanks instead. You can thus pick up a 1p copper coin with a magnet these days. Same for most of the coins now. The concept that they should be worth their face value in raw metal was abandoned decades ago. I think the last time they even attempted that was the original "pound coin", which was mostly cheap white metals with just enough gold plate detailing to make it worth roughly £1 in raw metal stock. Today they are all steel cores.

author: themadhippy
author_rank: Super Contributor
timestamp: August 25, 2024, 03:01:36 pm
content: Quotecant buy 1/2 or an ounce of baccy anymore,30g is the minimum size.Not sure how thats meant to help you cut down on your smoking as i found the 30g packs didnt last any longer than the 25g pack so my smoking went up 5g a week.

author: coppice
author_rank: Super Contributor
timestamp: August 25, 2024, 06:24:21 pm
content: Quote from: paulca on August 25, 2024, 02:06:29 pmInteresting. Where is that? Around here (York) and other places I've been in the UK its all round numbers of pints for normal full fat, semi-skimmed and skimmed milk. Milk is sourced regionally by the supermarkets, so are some parts of the UK working one way, and some working another?

author: SteveThackery
author_rank: Super Contributor
timestamp: August 25, 2024, 08:08:46 pm
content: Quote from: paulca on August 25, 2024, 02:06:29 pmYou obviously missed my previous post where I quoted the milk in my fridge. It is labelled "4 pints, 2.272 litres".