dst.. you can parallel charge your battery's they way you ask.. but I really have No faith in the parallel boards I have seen. they all are failure prone . and when ur putting 20 amps into a 4000 mah lipo that could result in bad things..

as 4 discharging no.. I suggest you get a 15/20/30 amp reactor discharger ..http://www.integy.com/st_prod.html?p...6#.VZ7iObWR-1s

one of these will discharge a battery in less than 10 minutes.. I have several and a Tekin 12amp/24 amp discharger... There was a post I think by howardcano on a reactor mode to adjutst internal pot to 7.8volts.. also get a lipo buzzer to monitor as it dis-chargers.http://www.rctech.net/forum/radio-el...r-2s-lipo.html