PSUs for Laptops

Sorry - strictly not a Windows question! Assuming plug and sockets match, are laptop PSUs interchangeable?
I have a couple of old laptops I want to sell off for local charities but I don't have matching PSUs. Under the circumstances I neither want to risk my existing PSUs nor buy matching ones for laptops which may not work.
I would expect all to use the same voltage and polarity.

Yes they should work...but just to be sure, make sure to check the polarity markings on both the laptop and the PSU, then also check the voltage that is in the same range (as an example 12.2 or 12.4V does not matter that much, as long as it is not way off. There are other voltage ranges laptops use also, like 19.1V etc...). And last but not least...make sure the PSU is powerful enough...too weak PSU and you risk burning both the laptop and the PSU and the PSU won't be able to charge the battery and power the device at the same time when the laptop is in use.

"I would expect all to use the same voltage and polarity."

That is not correct, some maybe interchangeable, but you will have to be careful and do some research.

The plugs maybe a different polarity and design/shape/size and have different output voltages and power ratings or proprietary charging standards/features.

It helps to have a background of electronic engineering experience.

The specs of the power adapters should be on the bottom. If the print is large enough to read is another thing. I need to use a magnifying glass.

Also note most of the plugs have a small center pin in them, if that is missing the unit may not be recognized properly by the Notebook/Laptop, may not charge.

Sigurd said:

laptop PSUs interchangeable

Click to expand...

Ian,

There is no generic answer.
- Dell power adapters, just for example, have an extra pin that identifies it as a Dell power adapter.
- Dell laptops will object if that pin is not detected [but will still cooperate if the required voltage & current are provided].

Having said that, I have a power adapter with changeable end connectors that I can swap around to power either my Dell Inspirons or my Lenovo IdeaPad as I desire.
So luck exists.

I re-wrote my post after realising that you were talking about the power adapter that sits between your source of electricity and the input connector of your laptops.
I had thought you were referring to internal laptop components. But we don't use the term 'PSU' for laptops because, generally-speaking, they do not have a single separate component doing the job that a desktop's PSU does.


All the best,
Denis

are you talking laptop charger?

Berton is correct.

modern charger, it's chipped by manufacturer. there is a chip to verify device ID, If NOT match, the charger won't charge/work.

say, HP laptop charger and Dell laptop charger, if you read specs only, they look identical, 19v 3.42a 65w, , , blah blah blah.
but they are NOT exchangeable.
the Dell charger won't charge HP laptop. similarly, HP laptop charger won't charge Dell laptop.

I have both Dell and HP laptops. Each has to use its own charger.

Thank you all for your information and opinions, and Dennis for educating me on the correct terminology regarding power supplies for laptops. More years than I care to remember building, using desktops and other electronic boxes and I thought Power Supply Unit was a generic term for the lot! I never knew it wasn't - obviously!
I'll flog the laptop without the thingys and and stress the charity angle!

You could try searching Amazon for replacement power adapters for each laptop model and note what the product pages say for each laptop model
- voltage requirement [you can exceed this a bit but cannot be below it],
- current requirement [you must get a power adapter that achieves this and it will not be a problem if an adapter says it will exceed it],
- power requirement [also essential but it is derived from the above and both of them must be satisfied],
- assuming it is not USB-C, connector pin external & internal diameters


All the best,
Denis

DELL and HP are a bit of a special case because they use "smart" chargers even on laptops with barrel charging plugs. The serial protocols are proprietary. HP ignores DELL chargers entirely while the DELL can be charged using a HP charger, but you get a warning about unrecognized charger.

@Sigurd

You could buy a universal laptop charger on Amazon for £15 (under $20).

My laptop uses a bog standard 90W Chicony A15-090P1A which weighs a fairly modest 18.2 ounces, and that happens to be interchangeable with quite a few laptop models from known brands including from Acer and MSI. I generally like to avoid buying into the added risk of, in the possible event that it breaks, having to go searching for a suitable replacement that might be out of stock everywhere excepting on some unfamiliar webshop that wants more money for it than the whole laptop might be worth selling for. The same with laptop brands like Dell that don't even let you install different RAM modules and/or a different NVMe SSD unless you buy it directly from them (i.e., vendor lock-ins). Some call it luck. Personally, I, am more inclined to refer to it as using a few brain cells. lmao

hdmi said:

The same with laptop brands like Dell that don't even let you install different RAM modules and/or a different NVMe SSD unless you buy it directly from them (i.e., vendor lock-ins). Some call it luck. Personally, I, am more inclined to refer to it as using a few brain cells. lmao

Click to expand...

Same thing with HP, but they're not as sensitive. With a bit of luck, you can get a lot of chips to work. Out of these "PRO" brands Lenovo on the other hand, they eat anything. Same with almost all brands more targeted at consumers.

SlicEnDicE said:

Same thing with HP, but they're not as sensitive. With a bit of luck, you can get a lot of chips to work. Out of these "PRO" brands Lenovo on the other hand, they eat anything. Same with almost all brands more targeted at consumers.

Click to expand...

Yeah, HP also, BUT... at least you get the Bang & Olufsen logo so no one will notice!

Ian,

If you search for laptop power adapters as I suggested, record the necessary data and only then assess anything described as a 'universal' power adapter.
- As I mentioned before, I have a 'universal' power adapter from an Amazon supplier that works in my Dell Inspiron & my Lenovo IdeaPad.
- I also have a Dell Inspiron power adapter from an Amazon supplier that does not work in my Dell Inspiron.


All the best,
Denis

If you buy from Amazon or any online retailer, you can just return it for 'any reason'. Here in the UK the mail man will collect it AND affix the shipping label.

hdmi said:

laptop brands like Dell that don't even let you install different RAM modules and/or a different NVMe SSD

Click to expand...

is this a new thing?
I've changed RAM & M.2 SSDs on Dells without any problems but that was a few years ago.


Denis

Try3 said:

is this a new thing?
I've changed RAM & M.2 SSDs on Dells without any problems but that was a few years ago.

Click to expand...

No, it's an old thing that, even though it doesn't apply to all models, is still reason enough for me and many others like me to steer clear of the brand until maybe one day they can release a new and affordable mid-range laptop with decent specs that would make it an excellent deal as opposed to not be able to know about such serious shortcomings before you already bought the damned thing and face the resulting unnecessary risk of having to send it back only because of them of course.

I've seen charities selling laptops with no charger and just leaving the buyer to get one for that model. Althought personally I've always bought the right charger for the laptop, if selling one I've previously fixed that had no charger or had a damaged one - but it usually eats a big chunk out of what you're selling the laptop for as I was wary of selling anything without an official manufacturer charger. If you sell them without a charger, it's up to the buyer whether to get an official manufacturer charger, or a generic "replacement" for that model - or use a power bank. Some will charge with a power bank, some won't.

My recent HP laptop can charge via the USB-C port. I think that is the future with every device powered by a USB-C