19.5v power supply to replace and original 19v one...bad idea?

LGabrielPhoto

LGabrielPhoto

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Hi!
I got a laptop with a dead power supply and it is rated at 19v with 3.68 amp
I have an extra one with the same plug but with rating 19.5v and 3.40 amp or so.
From what I recall amp is fine to be more since it only uses what it needs but voltages are the ones that must match but still...is .5v that dangerous?
Thanks
 
Don't do it. Especially since the max output current of the latter power supply is .28 less amps. Even if your laptop successfully booted on that power supply, I would bet that thing would run a bit hotter, shortening its lifespan. Might also be a potential fire hazard depending on the brand and quality of that power supply.
 
It'd be fine. May not charge the battery as quickly, but most modern laptops can vary voltage input within a few volts, yours is less than one. The amperage is not significant enough of a drop to cause problems.
 
Is not a modern laptop though, came with XP and its a 1.4 intel. The battery wont hold charge for more than 30 mins at best so charging is not my main concern.
I was able to use another power with less voltage 18.5v but a lot more amps close to 5. Is that also risky?
Thanks guys
 
shaolin95 said:
Hi!
I got a laptop with a dead power supply and it is rated at 19v with 3.68 amp
I have an extra one with the same plug but with rating 19.5v and 3.40 amp or so.
From what I recall amp is fine to be more since it only uses what it needs but voltages are the ones that must match but still...is .5v that dangerous?
Thanks
Click to expand...
The voltages are not likely far enough off (2-3%) to hurt anything. Most regulators have a decently wide operating range, the laptop should deal with the difference.

The current difference is also minimal. Essentially it sounds like you have a 70W vs. a 66W, 5ish% delta. There's going to be much more margin than that built into the operating spec by any decent manufacturer.

I'd use it, and not sweat it. A smidgen longer to charge should be the only drawback.
 
You'll be just fine with the replacement, the tolerances are more than acceptable - .5 volts and .28 amps are nothing in the big picture. It'll work fine, just make sure the two plugs are exactly the same. I know you say they're the same but with laptops nowadays there are 2 conductor as well as 3 conductor plugs out there.

2 conductor plugs are the typical style from years past, with a ground (the other shielding) and the positive (inner shield), but what's more prevalent in today's world are "smart adapters" which add a 3rd conductor, usually a center pin in the middle of the plug, which is part of a sense circuit which let's the adapter know "ok, we're plugged in, start charging," etc. It also can use a resistor circuit so that the laptop verifies if it's using a "legit" power adapter from the actual branded manufacturer so there's no chance of damage, etc.

The voltage and the amperage are close enough that you're not going to have issues, it's the plug that matters more in this case. If you plug the "new" adapter in and the battery charging circuit goes to work, you're covered.
 
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