Repacing a dead laptop battery

[gabemcg]

Sony Vaio PCG-505f

dead battery = model #: PCGA-BP51 11.1V/1550mAh

on ebay, when I search for the battery model # I get battteries that say they are compatible with my laptop, but have ratings of 11.1V/1800mAh and 11.1V/2200mAh

which should I buy? I have no Idea what dif they would make, but I'm guessing there is some difference, is the higher number more power? will one hurt my laptop? go dead quicker?

thanks in advance for replies!

 

[CrispyFried]

the higher the maH rating the longer the battery will last. so the 2200 maH one is better from that standpoint.

as long as the 11.1 Volt rating is the same its OK.

 

[cheesehead]

Voltage is what will fry the laptop. mA is not really important for batteries. (PSUs, yes.)
Voltage is a measure of potential, kind of like the octane measure in gasoline. More octane means a bigger bang. Too little octane, and your race-car won't start. Too much octane, and your moped blows up.
mAh is a measure of capacity, like the size of the gas tank. Assuming that the gas and tank have no mass, it's kind of like adding a second gas tank to your car; just because there's twice as much gas, does'nt mean it will use it any faster.
I'd go for the 2200mAh battery. That said, I'd make sure it's made by either Sony or a well-known aftermarket supplier if it's a lithium-ion or lithium-ion-polymer battery. If they were to rupture, the resulting fireball could easily char a femur.

 

[CrispyFried]

Originally posted by: Cheesehead
Voltage is what will fry the laptop. mA is not really important for batteries. (PSUs, yes.)
Voltage is a measure of potential, kind of like the octane measure in gasoline. More octane means a bigger bang. Too little octane, and your race-car won't start. Too much octane, and your moped blows up.
mAh is a measure of capacity, like the size of the gas tank. Assuming that the gas and tank have no mass, it's kind of like adding a second gas tank to your car; just because there's twice as much gas, does'nt mean it will use it any faster.
I'd go for the 2200mAh battery. That said, I'd make sure it's made by either Sony or a well-known aftermarket supplier if it's a lithium-ion or lithium-ion-polymer battery. If they were to rupture, the resulting fireball could easily char a femur.

youre analogy of voltage=octane is off. octane is simply the measure of fuels resistance to predetonation (ping), not energy potential. a racecar engine will run but eventually destroy itself on low octane fuel (due to predetonation melting the pistons) and a moped will happily run all day long on high octane racing fuel with no damage (but no increase in performance either).

a better analogy is fuel pressure, ie loo low and not enough fuel is delivered to run (or runs very poorly) too much and the fuel line, rail or injectors blow out or rupture.

but the gas tank anolgy is correct, the 1800 maH is a bigger "electric tank" than the 1500.