ah yes, when i described the throttle i said there are three wires.. where there are cases where there is a 4th wire. that 4th wire carries the full voltage across your battery and is meant as an indicator (it only carries the full voltage not full amperage, thank God.)

that indicator wire is hooked to a series of LEDs which light to let you know what voltage you're at.

so the answer is yes, it's normal that under load the battery pack will read a lower voltage than nominal, and as a consequence your LEDs will reflect the same. i wouldn't put too much stress on that indicator, i personally don't like it much _ it's a gadget mor than anything else, IMO,