Looking For Power Adaptor For Custom Computer

I have a computer built by Lotus computers. They seem to be defunct now but when I bought from them they advertised as selling laptops made in the U.S.A. They were getting Clevo computers and customizing them and I found a letter from the FTC that said what they did did not warrant the "Made" or even "Assembled in the USA." That's not super important, but the point is, whatever tweaking they did, I'm not sure how much effect that'd have on power adapter variability.

I have the Clevo w650sz model number and it calls for 19 volts and 4.74 amps. I know the amps just need to match a minimum. I also know the voltage needs to be very spot on, but adapters that are advertised as suitable for this computer on amazon are half a volt highers. I thought I read long ago that there was a fudge factor of half a volt, but I couldn't find anything documenting that wiggle room so I'm hoping someone here could confirm or refute that.

Otherwise, I'd have to get an adapter from China which seems spot on with the numbers. Well, I don't know that we could wait for something shipped from China. Right now, this is for our church and the original adapter was lost, and I'm hoping for a quicker solution.

Also, I'm looking at universal adapters but I'm not sure that they will have the model I need, but I've asked one of the vendors at Amazon, but then there is also the issue of polarity which I'm not finding listed among the specs.

 

When replacing power adapters I always go for one that has the exact voltage but like you I have read that a small variant either side of that should be fine, although I have never tried but read on.

Generally, I have found that when measuring power adapters with a voltmeter they are usually a bit over ie 12v will register 12.30v, 5v will register 5.12v.

I recently tested 2 power adapters, used for routers, which were stated to be 12v output with a voltmeter and they both registered 13.5v.....

Personally, if I had to buy a non voltage spec power adapter, I would rather go for a bit lower than a bit higher ie 18.5v rather than 19.5v for a 19v spec.

I am sure that other users may reverse my order on the basis that a power adapter will weaken over time.

The other thing that you should not overlook, when replacing a power adapter, is the tip ie the metal bit that you plug into the laptop / unit. They are usually 5.5 mm wide with the inner diameter 2.1 or 2.5mm wide (although there are many other variations). If you have overlooked that aspect, look again at your power adapter to make sure that you are getting an adapter that will fit.

 

The voltage should be the exact same. Even 1/2 volt high could result in battery damage. 1/2 volt less could mean the battery will never get fully charged. And if the voltage is not as expected, the notebooks voltage regulator circuits will attempt to compensate which will put more strain on them. Even if able, it WILL result in more heat being generated which, at the very least, can increase component aging.

As for current, you can safely go higher. But you should never go lower. The problem is the charger must be able to support charging a fully discharged battery (when maximum draw occurs) but the charge must also, at the same time, be able to run the notebook while charging. So a lessor charger may be able to charge the battery, but may not be able to run the notebook at the same time, or worse, the charger may overheat.

Your current charger should have a symbol on it showing the polarity similar to this.

I recommend and use a similar Universal 90W Notebook Power Adapter. I use it on service calls and when troubleshooting notebooks. You select the proper tip and voltage (this one automatically adjusts its output voltage) for the battery and notebook. Thus far, I have had no problems using mine on my own Toshiba, as well as several clients’ Dells, HP/Compaq, eMachine, Sony, Lenovo, Acer, and even Apple notebooks.

Note there are other universal adapters that are only 65W. Those may be fine for smaller notebooks, but I would not try it on a 17" notebook that has a discharged battery.