EBay universal chargers?

Hello,

I was hoping to buy several universal laptop power adapters/chargers as spares for the office, but am having trouble finding something that's truly universal. Browsing sites like newegg.com, it seems few reviewers find any of these products redeemable. And most manufacturers don't seem forthcoming with compatibility data. Actually, the best technical data I've seen is for the universal chargers listed on EBay. And as they're all likely made in China anyway, I don't think I should rule EBay out. Has anybody bought a universal charger from there recently? How is the quality and how compatible has it been? I was hoping to find something to power and charge 5 different laptop models, probably the toughest being Dell's Lataitude D520 (19.5V, 3.34A) and Lenovo's T61 (20V, 3.25A), both of which have a center pin on the power connector. (This is apparently not a universal feature, and may stand between powering a laptop and actually charging it.) Does anybody have suggestions, or has anyone seen articles written on this subject?

Thanks,
Todd

 

Universal power supplies are being put to rest. I cant think of any current laptop which can use one. Almost all laptops now have a built in impedance checking device hooked up to the power circuit board. If the impedance of the power brick is not the same as the normal one the impedance value will not match the value of the systems charging circuit and the system will reject the power supply. Because of this, you cant just use any power adaptor with any laptop you want. You need to buy the right one, or else it will not work.

K-TRON

 

Hmm, this wasn't what I expected to hear, so thanks for the advice! But I assume this impedance check is some kind of battery safety mechanism, and not meant as an anti-competitive measure? Some universal chargers have an explicit slider on the side to select the voltage. Seems it wouldn't be impossible to add an ohm nob, too. I'm no engineer, but any thoughts on this?

Our Dell's and Lenovo's are all less than two years old, but the laptops that I really wanted to use with the universal chargers are from 2005-2006, so I will likely buy a single cheap charger from EBay for testing. Even if it doesn't work well, we'd be out very little money. And I'm now even more curious to see the results.

Thanks!

 

Dell is annoying. They will reject universal power supplies because they don't supply a Dell code. Happened with my wife's 1520... the power supply ran the machine, but it wouldn't recharge the battery because the laptop wouldn't "authenticate" the power supply. That said, my T61, Compal HGL30 and my mom's Compaq all work fine with the universal charger. Your problem will only be with the Dell, and I know of no way other than just getting another Dell charger.

 

Cool. Which charger are you using? How long have you owned it?

 

Does anybody a recommendation for a specific charger? If not, I'll just make an educated guess from what's being sold on EBay. Thanks.

 

Sorry... I bought a Belkin universal charger for my wife (I can't remember the model) I ended up giving it to my mom since it wouldn't work with my wife's Dell. Experience is the best teacher But it's still working fine to my knowledge, and it has been for the last year or so. I really wish that it had worked because I really liked the USB charging features on it, didn't have to use up a USB port on the computer or even turn it on to charge phones and iPods and such.

 

What is the purpose of having to use a Dell power supply? Safety? (If you try to use another one, will it blow up your computer?)

 

It is so people do not plug the wrong voltage chargers in. Dell, and HP have done this in many systems. It is a great technology. You wouldnt believe how many people try to use the wrong psu with the wrong laptop.

IBM/lenovo is more lenient. Almost every laptop they make has the same charger, ac power in jack and usually teh same voltage output, so they are pretty interchangeable.
However not all machines are like that, so impedance matching helps protect your system if you were to use the wrong power supply.

K-TRON