I have a 2005 master replicas luke skywalker ROTJ force fx lightsaber thats missing its 6xAA battery/speaker pack. What can i use as a replacement? I plan on using the stock soundboard and thought maybe i could use the tcss 4xaaa battery holder or the TrustFire Protected 3.7V 2400mAh 18650 removable Li-Ion Battery instead.