Battery life

What is the Battery life – these days?

Do these new batteries not like being left discharged?

Have a Win10 Portable – that wont charge – ie it says its 100 persent charged – but seems to be flat :-(

NiMH and LiPo batteries don’t have the memory effect that NiCd batteries had. That required occasional deep discharges to maintain the full capacity. They do not however like being left discharged.

I’ve also seen a reference to issues with Windows incorrectly showing battery status, which may be what you are seeing.

My experience with laptops in schools a few years ago suggests that the newer batteries can become unusable within 3 years and need replacement. They stop quite quickly. NiCd however gradually lost capacity over a couple of years. My personal laptop is now 7 years old and still giving over an hour of battery operation. It’s an HP NC6400. I don’t know what battery type it uses. The replacements now on sale are Li-ion, but I don’t know whether that is what the original one is.

There are also soft switches on many laptops that switch off the battery or the charger for the battery.
Usually involves pressing Alt and a function key simultaneously. The key combinations vary but my cats seem to pass the info on the quirky combinations down the generations or divine them by some unknowable means.

The total lifetime of a battery is dependent on several factors. These factors include battery type (NiCad, NiMH, or Li-ion), how often the battery is used, and its age.

Which is why I show battery life as a percentage – for a Li-Po battery this correlates with output voltage whilst discharging.

for a Li-Po battery

Lithium-Polonium battery? Surely not…

Lithium-Polonium battery? Surely not…

I did wonder about that, but it is a long time since I lectured to electrical engineers about the chemistry of batteries 8)

Given that only one isotope of polonium has a half-life over six months, and the half-life of that one is only about a hundred years, I’d rather not have very much of it in any battery in my house. That isotope doesn’t even occur significantly in nature: the only one of any significance is Po210 (the nasty stuff they murdered Litvinenko with) that occurs in nature because it’s in the decay chain of U238. Po210 has a half-life of 138 days – that is, (a) it’s very radioactive, and (b) it doesn’t last all that long, so your battery’s chemistry is going to change fairly rapidly. It’s a powerful alpha emitter (5.7 MeV) which in itself would be quite interesting in its chemical effects.

Not sure on modern battery types – some seem to suggest that the laptop battery boxes come apart.
Ie a strip of tape removed – exposes the batteries – seems they are in pairs (parallel)

Wouldn’t have thought that was a good idea :-(

The battery box here -it’s difficult to see how it would come apart.

Lithium-Polonium battery? Surely not…

I can’t tell if either of you are joking, so to make sure it’s clear, the Li-Po that Chris Hall is referring to is almost certainly Lithium Polymer.

https://en.wikipedia.org/wiki/Lithium_polymer_battery

I can’t tell if either of you are joking

Just interpreting Li-Po as a chemical formula rather than “too lazy to write Lithium polymer”. ;-)

I can’t tell if either of you are joking,

I don’t think either Clive or myself were seriously thinking polonium (Clive has explained all above).

I can’t tell if either of you are joking

Sorry Jeffrey. Yes, Joe King. Apart from being a tad expensive, polonium is VERY unsuitable for use in batteries. Not even much use for RTGs.

I was also taught, in the context of problem solving, that the technique ‘Po’ (from, I think, the Chinese or Japenese) is to constrain a solution to provoke ideas. For example in a problem of transporting people by bus the various constraints ‘buses have no wheels’; ‘bus has no driver’, ‘bus has no seats’; etc. all provoke ideas such as standing room only, guided busways etc.

is to constrain a solution to provoke ideas.

Japanese, I’d imagine. Given their environment, they’re world class at disaster planning which will require a lot of “let’s add constraints and see what ideas we can think of”.

Boss: Let’s see. Nuclear power plant. Massive earthquake so no power to the cooling pumps. Huge tsunami wipes out diesel pumps. Now what?
Employee: That’s so unlikely, we might as well be planning for a meteor strike.
The year 2011: Hold my beer.

;-)

Speaking of Japanese ideas, at work they’re introducing the 5S system. In Japanese that’s seiri, seiton, seisō, seiketsu, and shitsuke. This gets translated into English as sort, set in order, shine, standardise, and sustain. In French they use the acronym ORDRE because there aren’t convenient S words.

The thing that strikes me about this is missing from the Japanese is shiawase (happiness) as a happy employee is a more vigilant and productive one.
And missing from the English? Safety. A much more important S word than “shine”.

With ref to no electric power for pumps – being able to call upon a helicopter that could carry a large generator.

Or perhaps a special helicopter who’s engine could directly drive a generator.

It’d be quite a helicopter that could carry a generator that big, or whose engine could power one. Have you seen the size of a nuclear reactor’s cooling water pumps?

In GB we have designed things so that the are multiple pumping-in points. With fittings that a fire engine can connect to. Diesel powered pumps, a tender full of water. Simples. Oh! and plants in other coutries similar to the Japenese reactor had tiny fans so that the hydrogen would not build up … Still on the plus side, they saved the cost of the fans.

With fittings that a fire engine can connect to.

Good idea, but following a severe earthquake and tsunami, how do you plan to get the fire engine to where it’s needed?

I don’t think I would build a nuclear reactor in an area prone to earthquakes.

A tsunami could potentially hit any coastal location, thousands of mile away from earthquake zones. If (when) La Palma slides in to the sea, a pretty big wave could come up the Bristol Channel which would make the Severn bore look like a ripple in a puddle. If Berkley or Oldbury were still operational, I’m not sure what we could have done if the Boron dust got soggy. Lets hope they’ve thought about that for Hinkley C.

a tender full of water

How many tonnes would that be? See http://clive.semmens.org.uk/Energy/EmergencyCoreCooling.html – a five hundred tonne fire tender would be quite impressive.

You can cool a low energy research reactor that way, but a power reactor? No chance at all. You’d need a lot of fire tenders and several intakes, and with more refilled tenders ready to take over every few minutes as the first ones are emptied. Back and forth, loads of tenders for the first few hours, just two would do after that – continuously until you can get a regular pumping arranged again.

I don’t think I would build a nuclear reactor in an area prone to earthquakes.

I wouldn’t build a nuclear reactor on an inhabited planet myself – not a power reactor, anyway. A low energy one for manufacturing isotopes for medical (and some other) applications, yes – although a linear accelerator or synchrocyclotron might be better.

People want electric goodies battery car’s TVs, StupidPhones etc.

Have given up on coal think it’s a good idea to burn North American Forests don’t want to build dams.

Also a while ago there was a Earthquake off southern Ireland which flooded part of SW England. (From old records)

Dumping the Electric energy into the sea or landmass – so the reactors can run their own pumps if pylons fail.