|
i think a much simpler explanation is in order. in simple electric motor theory the ac/dc universal motors used in aeg's draw current from a battery in 2 ways. one is the simple resistive losses of the fine motor windings + the resistive losses of switches, wiring, conectors etc (very small). the other is the inductive losses of the motor windings as the motor rotates and phase reverses on the motor commutator. as speed varies (with higher or lower battery voltage), the frquency of this phase reversal also will vary. this can be calculated by the formula xl=2 x pi x frequency x inductance. basic math will tell you that as speed increases, frequency increases and inductive reactance increases. this means that the motor will draw less current at higher voltages and more current at lower voltages. this is really simple so don't get confused. basically what i'm saying is that voltages from 7.2 to 9.6 should be fine and remember mah rating means nothing when it comes to rof. this is a voltage issue. mah means "current delivery capacity" and simple math like volts x mah is garbage. batteries work on a geometric scale and you can't use that formula for any kind of accurate calculation. when an 8.4 v battery reaches about 5 volts it is totally depleted so those 5 volts that were used in your "volts x amps" calculations are just plain garbage. remember too that an electric motor draws alot of "inrush" current on start-up (which means everytime you pull the trigger) when there is no counter-emf generated by the motor to balance out the high starting current, so this will deplete your battery even faster. a higher mah capacity battery will help out in this regard.
|