charging dual lipo packs

since most everyone uses dual packs in their trucks... has anyone thought of charging thier dual pack together... i've got two 2S apogee 5800's that i'm planning on running in series in an e revo... my plan is to charge these two packs together as a 4s 5800 pack with a balancer... i've got two balancing cables that i plan on making into a y connector for my balancer... anyone tried doing something similar... it would cut the charging time in half!!