One pair of the leads is for putting the charge/discharge into/out of the battery. The other pair of leads is for VERY ACCURATE voltage measurement.
The way I understand it, when you detect voltage off the same set of leads you're charging from, there can be inaccuracies.
Since you paid an arm and a leg for the best charger on the planet, you might as well NOT DEFEAT what makes it so great -- VOLTAGE MEASUREMENT ACCURACY.
Randy Clements
Salt Lake City, UT