Any charger can actually supply a lot more current than it's rated for - not for long, but it can. (Short the output of a charge and it'll supply tens of amps - for a fraction of a second before it dies a spectacular death.) The phone draws what it's designed to draw to charge the battery - as long as that much current is available. If you're using a USB 2.0 port to charge, it's limited to 100mA, or 0.10 Amps, so that's all the phone can draw. If the phone is designed to charge with 1.5 Amps, using a charger that can supply that much current will charge the battery faster, and it won't hurt anything. But phones have been standardized to charge with a 5 volt source, so just about any 5 volt source, regardless of the available current, will work. (If the charger can't supply at least 100 mA, you may damage the charger, but you won't damage the battery.) But if you have 5 volts at 100 Amps available, you can charge a lot of batteries at one time with no problem.
If you have a charger that can charge the battery out of the phone, you can overcharge the battery, Chargers like that are designed for specific batteries, and you should only use them with the battery they're designed for, even if a different battery fits.