RE: 50cc Power Expander
Hi,
You could but when the batteries get below 6.5V the servo voltage will start to drop with the battery drop, when the batteries get to 6.0V the servos will see 5.5V. For A123 batteries I recommend the PowerExpander Sport Plus. It does not have a regulator in it but this is just fine for most servos. The receiver still sees 5V.