Hi, I think that mAh is effect on working time of phone, although it don't effect on voltage of battery. So I'm sure that 540mAh battery has lasting time shorter than 1000mAh one.
My result is: After writing original FUBU into phone, the battery indicator is correct, but it don't increase standby time. My phone shut down when voltage over 3700mV, it is about 4220mV when full charge. Standby time about 3 - 3,5 days.
Someone from my coutry said that he can find out the suitable values for each battery, but very difficult and waste time, and if he buy a new battery he has to look for new values, although choosing only one kind of battery.
Oh, it is very difficult to know why SL45 has the big problem on battery?