Maybe using 2-30gb hard drives is draining all of the power when both are runup to speed

Unlikely.

The amount of power consumed by the empeg (even with two drives) is absolutely minuscule compared to many of the electrical systems in your car. For example, stepping on your brake pedal will cause the brake lights to use more power than the empeg ever would, and something like your windshield wipers or rear window defroster consumes power at least one and possibly even two orders of magnitude higher.

If your battery/alternator couldn't handle the tiny load of the empeg spinning up its disk drive(s), then the first time you turned on your headlights your car would probably stop dead in its tracks.

tanstaafl.