My son came home from college for a long weekend with his HP laptop. He forgot to bring his charger. I said no problem, I have an HP laptop. It turned out the plug for my laptop was a different size than his, so my charger didn’t fit. I said no problem, I have a universal charger. So I pulled out my charger with a bag of interchangeable plugs, and none of them fit his computer.
We have this problem with our laptop inventory at the office. We have Lenovo, Dell, HP laptops, all with unique power plugs.
Why does every manufacturer use a different size plug than every other manufacturer? And why do they even use different plugs on different models of their own machines?
The cynic in me says it’s so you have to buy their adapter if you need an extra or a replacement, but the industry has standardized on so many other things it doesn’t seem like that’s the right answer.
Planned obsolescence. Every manufacturer wants to keep their niche, but only for so long until the upgraded version comes out on the market. Then what was once new is now old.
Oh, BS.
Changes in charger connections are driven by size reductions and technological requirements. Also, standardizing on a particular connection is risky, because there’s no standard for the power requirements on laptops or chargers, leading to possible damage to the laptop due to plugging in the wrong charger.
It’s partly because different laptop models have different power requirements. If your 17" laptop needs a 150W power supply, you don’t want to use the same plug as a 13.3" ultrabook that needs only 60W. If you do, you risk someone using the the 60W power supply on the 17" laptop and overloading the power supply, or have the laptop behave erratically because of the inadequate power supply.
The bottom line is: it doesn’t benefit the laptop manufacturer to do this.
For example, for a decade, Apple used the same power connector for all their laptops - the MagSafe connector. Any MagSafe charger could power any laptop, although the 65W charger would take longer to charge a big machine vs the 85W one. I’m sure that if Dell or Lenovo wanted to license this connector from Apple, they would have been happy to do it, but manufacturers don’t want foreign power supplies powering their computers - if you burn up your computer with a crappy Chinese power supply, they don’t want to pay out on a warranty repair. So, they often use proprietary connectors, to force the user to buy authorized power supplies.
My understanding is that there is a range of different types of connector from a charger/transformer into a laptop/tablet. My laptop manufacturer’s charger/transformer failed (irritatingly, I suspect something loose in an enclosed cable connection, rather than anything more complicated), but it wasn’t difficult to get a general purpose replacement providing the right output, but with the whole range of connectors for different types. But it took some looking up to make sure which generic power supply would meet the right specs.
But you might as well ask why all car manufacturers don’t have identical spare parts, tyres, dashboard layouts, and so on.
I’ve got a “universal charger”, with plugs that are compatible with about every brand out there. They are rated “up to X” and supposed to be able to detect how much charge should they actually be sending.
They work fine with every brand we’ve tried except Dell (haven’t tried Apple). Dells will just stay at whatever charge they were, they won’t charge up. What is supposed to be the advantage of that? As someone who often travels with two laptops, forcing me to carry the Dell charger if I want to be able to use their laptop in a place without plugs doesn’t make me fond of their brand.
Dell laptops communicate with the charger using the 1-Wire protocol, and will only draw power if it can verify that the charger can provide the correct voltage, sufficient current, etc. It’s a safety measure. Drawing too much current from a power supply may cause the power supply to overheat, or otherwise behave in unpredictable ways.
Not quite the same. I am talking about the interface to the outside world, not parts within the form factor. Car parts are not standard but certain interfacing aspects are. The tires come in different sizes, but those sizes are standardized–if I buy a P215/65 R15 tire, I can buy a wheel of that size anywhere I want, and that wheel will fit on any car designed for that size. I don’t have to buy a Toyota tire to fit a Toyota car. (It used to be that the light bulbs were standard, although now to replace a headlight instead of spending $10 at your auto parts store, you are spending $100 or more for something specialized.)
Witness modern mobile phones which, with the notable exception of we-do-it-our-way Apple, all charge using a micro-USB port, and are compatible with nearly every power supply that accepts a USB plug. There are exceptions–IME phones will complain if the power feed is out of range. I have an LG3 and one one occasion it told me charging would be slow. I have had other phones that say that it’s an unauthorized charger and can’t be used. Whatever that means.
USB-PD is an attempt to standardize power interfaces up to 100W. I worked on this a few years back at an earlier job, not sure what the status of the effort is. The idea is to add smart, (potentially) bi-directional power charging to the USB interface (using new heavier USB cords - they were trying to keep the current USB plugs and jacks). There would be no power port on your laptop - you could charge it from a USB-PD power brick or from another USB-PD device that had the capability of supplying sufficient power.
One use case is adding USB-PD ports to a monitor, so that you can plug your laptop into the monitor and the monitor (which is plugged into the wall) powers the laptop (and the video from the laptop goes over the USB data link to the monitor, so one cable does everything).
However, going the other way is perfectly fine, as long as the 60W device’s power supply is designed to handle the higher wattage. Bigger rectifier and regulator is easy; but the regulator will run hotter, which requires a bigger heat sink. I can see why smaller devices wouldn’t have this, just not enough room.
My last experience dealing with a power supply provided 230 VDC filament voltage … the widowmaker … couple of big fans venting to a 65ºF room … still was hot enough to cook food and make a nasty mess if the food spilled …
The interface to the outside world is the plug on the wall. You’d like if it was closer to the computer but manufacturers don’t consider that to be the case. I agree it would be much more convenient for the consumers if it were true.
Most tires are standard sizes but some aren’t and are only made by a very few manufactures. It’s particularly true with directional tires. But wheels aren’t nearly as standardized as there are over a dozen different wheel bolt patterns on cars that are completely incompatible. Some are more common, but there are many still in use. These are all design decisions made by car manufactures and when you get to performance cars you’ll see more variations from the standards because for those applications performance trumps convenience.
This is true now, but certainly wasn’t early on in the days of cell phones. And now with wireless charging you’re seeing two new incompatible charging systems (Qi and Powermat). Granted it doesn’t seem that laptops are in the situation where the technology is changing quickly, but I suspect you’ll see wireless charging in laptops eventually. Hopefully a standard will have developed by then, but the requirements for a laptop charger may be different than for the cell phone chargers today.
I don’t know how sound the advice was but a computer technician once warned me against using universal chargers. He said they coud damage the laptop. Anyone know if this is true?
OK, so perhaps they are programmed to draw only a certain amount of power if the laptop cannot verify the power supply’s capacity. Enough to run the laptop, but not enough to run it and also charge it at an appreciable rate. (Charging the battery takes more power than running the laptop - evidenced by the fact that it takes less time to charge the battery than to drain it through normal use.)
Yes, it’s true.
If you don’t know the voltage that the laptop requires, and the universal charger is set too high, it could fry the laptop’s power converter circuitry.
I was hoping someone would bring this up. The history of charging devices for mobile phones et al is completely on-point.
10 years ago, you would not make any such statement about cell phones, because every single one used a different (manufacturer-specific, usually; sometimes, device-specific) power connector. Just like laptops.
What changed is that in 2009, the EU proposed a voluntary rule* that new smart (data-using) devices sold within its jurisdiction should have a charging port based on micro USB B.
*“voluntary”, but with a threat to make it mandatory if there weren’t enough takers.
It’s voluntary, but a lot of companies shrugged and signed on, simply because once the market leaders came on-board no one wanted to be the odd one out with their proprietary connectors. Except Apple, who loves being the odd one out on their own terms, and commands enough independent market share to be immune to competitive pressures towards any kind of interoperability.
So the answer with respect to laptops is that no one has proposed a standard and given it the teeth to make the manufacturers honor it. Since laptops are much lower-volume than cell phones, there’s probably less consumer pressure for it, so less political will to make it happen.
In my experience this isn’t the case. For a Dell, for example, you have AC adapters going from 65W (smaller Dell Latitude) all the way up to 240W (huge Dell Precision) that all use the same connector. Power requirements have nothing to with it, Dell just doesn’t want you to use their charger on an HP or Lenovo, etc.