Originally Posted by
Dave Wilshere
if your digital servos can draw 5A you have big issues! 40A total!! The Rx would blow to pieces...
4.8v batteries are only at 4.8v when they are completely flat, they charge to 6v and operate happily around 5.6-5.7v. It's why JR '4.8v' servos are happy at 5.8-5.9v, it's the voltage they were designed to work at!!
its how the servo motor is powered/controlled that makes the difference between digital and analogue servos. Manufacturers have different ways of doing this in both types, some cope, some don't.
The high currents of HV digital servos are why we use power distribution systems. Not using a power distribution system in a giant scale plane using multiple digital servos on a control surface is why people who simply plug into the Rxer often run out of power and crash, wondering why. You may want to consider some additional reading on the topic.
Most 9+ channel Spectrum Rxer Manuals tell you flat out not to use 4.8 V batteries. Wonder why? Also, many articles are published on this topic.
Bottom line: Analog servos operate sequentially and Digitals can operate simultaneously. When using digital servos the current used simultaneously adds up and, ... some of these servos can momentarily draw up to 5 amps. You may not see that level on your current meter because of the meter's refresh cycle time is too slow. But, it shows up on a good scope with a lock. Again several articles on this topic are out there and easy to get hold of.