My Lappie's charger died. I dug around a found another charger which plug fitted the socket perfectly. However, the power ratings differ.
Laptop:
19V DC
1.58A
Charger:
18.5V DC (Slightly lower than original. Should be okay)
4.9A (Higher than original charger. Is it okay?)
I don't want to fry my laptop.
Originally posted by SBS1984E:My Lappie's charger died. I dug around a found another charger which plug fitted the socket perfectly. However, the power ratings differ.
Laptop:
19V DC
1.58A
Charger:
18.5V DC (Slightly lower than original. Should be okay)
4.9A (Higher than original charger. Is it okay?)
I don't want to fry my laptop.
Don't try.
The amperage is SO different.
Rule of thumb:
Just get a charger which is specified for your laptop. Better spend a bit on that rather than getting your laptop fried.
I use a  MacBook bought in 2009(not the white, the alum ones) and we have a specified charger for it. I don't even dare use my friend's  MacBook Pro or even  MacBook White chargers. They have different specifications(a little).
I have seen what using another person's  MacBook Pro charger could do to a  MacBook. Trust me, it ain't pleasant.
No. There are plenty of factors to consider such as the polarity.
It has to be of the same voltage. 19V DC.
Having a higher amp rating is ok, the Laptop will only take what it needs.
Additional: Higher voltage is a no no.
Please check if it's the power cord that's the problem, sometimes, it could be that.
Else, get a replacement if it's still under warranty (6 mths/ 1 year warranty) depending on manufacturer. Or buy an oem adaptor.
For Universities, polytechnics and other local institutions, it's 3 years warranty unless otherwise stated.
Originally posted by SBS1984E:My Lappie's charger died. I dug around a found another charger which plug fitted the socket perfectly. However, the power ratings differ.
Laptop:
19V DC
1.58A
Charger:
18.5V DC (Slightly lower than original. Should be okay)
4.9A (Higher than original charger. Is it okay?)
I don't want to fry my laptop.
If the voltage differs, don't use it. If the amperage on the charger is higher than the laptop's amperage, then its fine.
The slight voltage difference may not affect the laptop in a negative way, but we cannot guarantee it, and as such it is advisable not to use it.
if you r not sure, go get a second hand replacement that will not burn your pocket.
that way you don't have to worry so much.
Power (W) = Voltage (V) X Current (I)
So how you charging it with 3 times the power of the previous. Your laptop will be charged 3 times as fast. But I cannot tell if it will fry your laptop? But perhaps it can withstand 10 times the joule heating?
But certainly, if you try that on the light bulb it will shine 3 times brigher.
Originally posted by Lokey:Power (W) = Voltage (V) X Current (I)
So how you charging it with 3 times the power of the previous. Your laptop will be charged 3 times as fast. But I cannot tell if it will fry your laptop? But perhaps it can withstand 10 times the joule heating?
But certainly, if you try that on the light bulb it will shine 3 times brigher.
The laptop will take only what it needs. My old charger was rated for 65W, using a 95W right now and there's no difference.
Originally posted by Raraken:The laptop will take only what it needs. My old charger was rated for 65W, using a 95W right now and there's no difference.
It depends. Some laptops cannot take it.
The MacBook being incompatible with the other versions such as the newer MacBook/Pro/Air is one good example. Even 15W difference, you try that for one year, your battery will gone case.
Originally posted by Fryderyk HPH:It depends. Some laptops cannot take it.
The MacBook being incompatible with the other versions such as the newer MacBook/Pro/Air is one good example. Even 15W difference, you try that for one year, your battery will gone case.
Adapters are designed to produce a maximum current, no more, but certainly less. It's like a power supply. Just because it has 300W of capacity doesn't mean it continuously provides that much power. In all my computing years (about 7+), I've never had issues mixing and matching adapters, as long as the things are compatible. Heck, I use ASUS and Acer chargers interchangeably as and when I need to. I do tend to buy oversized adapters for my friends when their chargers kick the bucket and none of them have reported any issues.
As for the issue you pointed out with Apple's MB/MBP Magsafe chargers, official word from Apple is that they are interchangeable, as long as the wattage is sufficient. Therefore, the 45W/60W MB chargers will NOT work with the MBP, but the 85W MBP chargers will work with the MB. (The newer 85W chargers have dual voltages, one for MBP and one for MB usage. The chargers auto-sense the required voltage. Unsure if the older chargers have this function.)
Originally posted by Raraken:Adapters are designed to produce a maximum current, no more, but certainly less. It's like a power supply. Just because it has 300W of capacity doesn't mean it continuously provides that much power. In all my computing years (about 7+), I've never had issues mixing and matching adapters, as long as the things are compatible. Heck, I use ASUS and Acer chargers interchangeably as and when I need to. I do tend to buy oversized adapters for my friends when their chargers kick the bucket and none of them have reported any issues.
As for the issue you pointed out with Apple's MB/MBP Magsafe chargers, official word from Apple is that they are interchangeable, as long as the wattage is sufficient. Therefore, the 45W/60W MB chargers will NOT work with the MBP, but the 85W MBP chargers will work with the MB. (The newer 85W chargers have dual voltages, one for MBP and one for MB usage. The chargers auto-sense the required voltage. Unsure if the older chargers have this function.)
That is the official word.
Yes they are interchangeable.
You can also use a MacBook Air/White charger for a MacBook or a MacBook Pro.
Just that, if you use it for too long, it screws up the Mac.
45W & 60W chargers work on the MacBook Pro. My classmates use my charger(MacBook) on their MacBook Pros all the time, but I simply refuse to use theirs.
Older chargers do not have the auto-sense function.
Originally posted by Fryderyk HPH:That is the official word.
Yes they are interchangeable.
You can also use a MacBook Air/White charger for a MacBook or a MacBook Pro.
Just that, if you use it for too long, it screws up the Mac.45W & 60W chargers work on the MacBook Pro. My classmates use my charger(MacBook) on their MacBook Pros all the time, but I simply refuse to use theirs.
Older chargers do not have the auto-sense function.
You're doing it wrong.
Macbook Pros require the 85W chargers. Your charger is providing more power than it is rated for. The reason I said it was incompatible is because MBPs draw more power than MB chargers are able to provide. The reverse is compatible. Your charger will cease to function if this continues. Using the wrong charger won't screw the Mac; it will screw the charger if the charger isn't rated for the load.
My schoolmate bought an early 2009 model MB and the 85W MBP charger, and her battery is still able to provide about 4 hours of battery life..
See we are talking about POWER here in watts. So 65W and 95 W, the difference is only 1.5 times. But if you compare and calculate the TS spec if it is 3 times the power of the previous.
Joule heating is also very important, as Q is proportional to I^2. R. So the difference in current will result is a jump in heating by the function of power 2 curve.
The point what me and Raraken are saying is, the laptop will only take the amount of current it needs
If voltage is constant.
And let the current be a variable amperage.
If the laptop only needs 30amps, even if the adapter can support up to 300 amps, it will only supply 30 amps.