Over Amping a Laptop Battery?

[TheGreatSatan]

My old laptop cord broke so I ordered a new one on ebay. The guy had high feedback and the picture and cord specs were exactly the same as my old cord so it seemed like a good buy. I got the new one in the mail today and it's not the same one pictured. It still fits my laptop and does provide a charge, but it's also a whole Amp higher in output than my old cord.

I know modern laptop batteries have some protections in place so they don't over charge or burn out, but is it enough? Can my battery be damaged by the higher Ampherage of the new power cord? Could one Amp really make that much of a difference?

EDIT: I think I found the answer

http://answers.yahoo.com/question/index?qid=20100917012637AActg1v

[diluzio91]

If i remember correctly, just because it's there dosn't mean its getting used?

[Fuganater]

All I know is that I'm paranoid about buying off brand laptop chargers. I spend the extra money to buy a brand new one from the manufacturer.

[xr4man]

as long as the voltage is right and the amperage is the same or higher you will be fine.

the easy way to think about it is that you cannot PUSH current into a device. the device can only PULL as much current from the power source as it needs.

so, just because the power source is rated at say 81 amps rather than 80 amps, your battery will still only PULL (for argument's sake) 60 amps.

the same thing is true for regular power supplies. if you have a 1000W power supply, that doesn't mean it's pushing 1000W all the time. that just means that your computer has 1000W to pull from.

voltage is a different story though. if you have a device that's rated for a 10v input and you put a power source with a 12v output, you will probably cause damage.

[AmEv]

Don't remember where I exactly saw it but...


More amps: You're fine.
Less amps: BAD!
More voltage: BAD!
Less voltage: BAD!

[xr4man]

yup, that's a very simple way of putting it, but right on the money.

[Twigsoffury]

http://www.surfersam.com/funny-pictures/funny-pictures-overclock.jpg

[dr.walrus]

That's fine, that's just the output capacity. The easiest way to think is that current is pulled; if the output of the charger is too little, it'd overheat the charger. Your laptop pulling 3a from a charger rated 3a will pull 3a from a charger rated at 5a. Good? Good.

[Oneslowz28]

Next time, take a look at both of Cooler Masters universal chargers. I have the 95w travel one and it is about 1/3 the size of a standard power brick and weighs 1lb. Its been to Vegas, and on several other trips with me.

[Konrad]

Li-ion and Li-poly secondary (rechargable) batteries actually have internal thermal fuses and voltage regulator logic designed with a fair safety margin to accomodate us dumb dumb ignorant consumers. Of course if these components blow out the battery is still wrecked, but at least it doesn't become a hydrogen-venting overheated sparking fire hazard which leaks corrosive alkalide goop into the chassis of your device. At least in theory.

Having said that, there are some battery chemistries (like automotive Pb-Na batteries) which will PULL as much current as they can get, and just like a gluttonous goldfish these will eventually explode in a nasty fashion if their consumption is not strictly regulated.

The rated output, in amps (or watts, if you do the simple math) of your wall wart is just the maximum it can sustain; if it's at least the same as the original part then there shouldn't be a problem; very much the same logic as the wattage ratings on a computer PSU, bigger is almost always better if price isn't a factor. If the voltage is off by more than about 5-10% either way then you could shorten the service life or permanently damage your device and/or your battery. Best to measure the actual ratings with a DMM while the charger is warmed up and sustaining normal electrical load, especially if you have a Shenzhen special without any certifications by recognizable authorities. Any warranty you've been promised may be impossible to claim 6-12 months from now when the vendor has disappeared.

The best test is to drain the battery to low charge, then plug it in and do some normal (or demanding) things on your laptop while it's recharging. Put it in your lap so you can give it poor ambient conditions for cooling, and see how hot it gets ...

[jelina]

if it's at least the same as the original part then there shouldn't be a problem; very much the same logic as the wattage ratings on a computer PSU, bigger is almost always better if price isn't a factor. If the voltage is off by more than about 5-10% either way then you could shorten the service life or permanently damage your device and/or your battery. Best to measure the actual ratings with a DMM while the charger is warmed up and sustaining normal electrical load, especially if you have a Shenzhen special without any certifications by recognizable authorities.My old laptop cord broke so I ordered a new one on ebay. The guy had high feedback and the picture and cord specs were exactly the same as my old cord so it seemed like a good buy.