In 1996, I bought one of the earlier land-line cordless phones by Sony, with a Sony-brand rechargeable battery, and the original battery has been going strong for 13 years now -- which I verified by double-checking the receipt in my receipt file, as I found it incredibly hard to believe! Over all these years, I have followed to a tee the directions in the manual to let the phone battery run all the way down until it died each time before putting it back on the base.

Meanwhile, I've bought a slew of other phones as backups, and their batteries always die after about a year, despite following the same procedure. But the battery in the old Sony phone still lasts hours and hours before needing a recharge; in fact, the length of time it holds a charge does not even seem to have diminished at all. So did Sony just make a better battery? Or was "programmed obsolescence" not programmed into the earliest rechargeable batteries yet?

a.) Your corless phone uses a nickel-cadmium battery which is why you are supposed to drain it fully. This is completely unnecessary for lithium-ion. b.) If you are comparing cordless phones to cell-phones, you are comparing apples to oranges. Cordless phones are very simple and only need to transmit over very small distances which uses very little power.

The so called "memory effect" in NiCad batteries is largely a myth

the MAIN source of pain in rechargeable batteries is the discharge rate. Remember, a battery is generating energy by letting a chemical reaction occur bwetween two ionized components. This invariably results in crystal growth

The faster you let the battery discharge, the faster the resultant crystal growth. And if you remember playing with Rock Candy as a kid, the faster the crystals grew, the larger they were.

Unfortunately, the larger a crystal is, the more stable a bonding structure it is. Which means that if you discharge at a rate above the "ideal rate" for a particular battery, you will grow crystals that are large enough that you cannot re-dissolve them at normal charging levels. Shipboard systems for example provide an Overcharge rate to deal with this in Lead Acid batteries, but you can't do the same thing with a cell phone or similar device.

So what does this have to do with your old Sony phone? Well the older phones OVER Specced the battery capacity. Furthermore as a household phone, the marketing perception was that you wanted to give a more "solid hand feel" to the customer - which means a bigger battery - which also means more talk time.

OTOH, newer phones started going down the "cell phone" path - by UNDERSPECING battery capacity and essentially over-discharging the batteries - thereby shortening their lifecycle by the creation of the above oversized crystals.

Thanks, this was helpful. I've been wondering for several years now about the longevity of my old Sony cordless phone battery, and none of the salespeople where I bought new phones had a clue. So you finally cleared up the mystery!

that made no sense. So bigger batteries result in more crystal growth (first 4 paragraphs), but then a bigger, over-speced phone therefore last longer? Can you go back and look up on the internet to clear up your confusion on the subject? It would be a shame if you weren't able to show yourself as an internet-expert on all subjects.

Try again Truett Do you really want to get schooled by me again?

As I already said, your post doesn't even make sense. You seemingly contradict yourself within the same post. I gave you a chance to clear yourself up, but you decide to take the whiny route, yet again... And schooled by you? Like when you said that .NET took nothing from Java (and insinuated that JIT was a Microsoft invention)? Like when you said that a good system BIOS helps run large programs? Man, I guess if in your mind you are teaching the world something, then you go ahead and keep thinking that. I was just trying to help you out, since I'm an engineer, I wanted you to know that you shouldn't say that kind of thing to engineers in real life, for they will immediately know you don't know what you're talking about. What is it you're going to be an "expert" in next by the way? Radioactive nucleotides? I think I've figured you out though... Slate is your way of feeling important, you can pretend you are an expert in all these fields by googling answers and copying the results, that way you don't have to feel so bad about your otherwise insignificant life. Does that pretty much cut it?

Go read it again. So far you are the only one who cannot understand the pist.

The rest of your assertions are similarly pulled out of thin air. I'll tell you this much, if you were an engineer working for me and brought that kind of comprehension skills to your reading of specs, you wouldn't last long working for me.

To TruetCollins: You misread my question. I wasn't comparing my cordless phone to cell phones -- I was comparing it to other cordless phones I owned, all of which also had nicad batteries. I never mentioned lithium-ion batteries at all. And I wasn't arguing with the article -- I was just wondering how a rechargeable battery could possibly have lasted for 13 years, and also whether the fact that newer ones don't seem to last longer than a year, when my older phone's battery has outlived a succession of other cordless phones and nicad batteries, is yet another case of programmed obsolescence.

To degs: Working for you? Ha, thats a good laugh. Where is it that you work? I don't even think you even have a job. How is it that you have time to post all this crap all over the place? If you actually do work in the tech industry, in any significant position, I guarantee that I either would know you personally or know someone who knows you personally. Where do you work exactly? What field? I can probably make sure you get fired for your utter ignorance of the BASICS of computer architecture, unless of course you are lying about your position. All I would have to do is trot out a couple of the whoppers you posted in the other thread, you would get canned in about 2 minutes by any competent manager.

So show us again where my ignorance of basic computer architecture is displayed?

Do provide us with a link.

yawn... How many times do I have to repeat myself? here's one example: degsme: "blah blah, p-code allows larger programs due to being more dense". me: yeah, excepting the fact that comptuers can't actually run p-code and the actual assembly will have to compiled, or even worse, the interpreter a LARGE mem hog, will need to convert on the fly. Any way you look at it, your statement is categorically false. Everything you say is either a Red Herring (an answer to a question not asked) or demonstrates a startling misunderstanding of computers and computer architecture.

yeah, excepting the fact that comptuers can't actually run p-code and the actual assembly will have to compiled, or even worse, the interpreter a LARGE mem hog, will need to convert on the fly.

Actually that's not what you replied. And interpreters aren't necessarily a "large mem hog", particularly when they provide VM capabilities that are more capable than what the underlying OS provides.

Nice try, but you are being dishonest about what you wrote, and you are wrong on the engineering front.

Try again.