I have taken two stock packs apart to make a 6v pack. I use it on an old plane only because I dont' trust my solder job 100%. It has worked fine though for 2 years now. The last 6V I bought was a 2000NiMih. I really like being able to fly all day without recharging. Your RX can handle 6V with no problem. I do use a heavy duty switch with the 6V but the stock one will handle it.

David