Check out this cool product called: On Board Servo Power Analyser by Safety Master:
On Board Servo Power Analyser Features:
● On-board Power Monitor Station
● Enables you to see what power your servos are using
● See your actual current, voltage and power draw!
● Recall the maximum current and minimum voltages from your flight!
SafetyMaster on board power analyser
This fantastic unit is designed to help you monitor power to your onboard R/C system. Batteries and BEC circuits are two of the critical areas inside your model and when things go wrong these two are often found to be implicated. Thanks to SafetyMaster you can see how safe your system actually is by measuring the current draw of your servos/receiver and by monitoring the performance of your battery or BEC under load.
The SafetyMaster draws a graph of current over time elapsed since turned on and shows total time elapsed plus battery capacity used. The graph is erased when the power source is disconnected. You can also manually reset the screen by entering “Yes” into the “Rst graph” parameter in the Warning Settings screen.
Warning Settings Screen
In this screen you can adjust warning thresholds according to your needs. Check out the specification of your receiver – or of your ESC if a BEC is used a power source, and your battery, and set warnings
Using a dedicated battery
Choosing a dedicated battery for powering your R/C system is often a better and safer choice instead of a BEC, but please bear in mind the following: a good battery maintains output voltage when a load is applied – or at least doesn’t fall below the nominal voltage. Note that with NiXX batteries – as the battery ages, so the voltage drops. Therefore, if you measure a large voltage drop during testing, it means that the load is too great or the battery is old or perhaps some component in the system has failed. Regarding the current limit; you should set max. current to around 95-100% of that specified by the manufacturer. If the load applied is below spec. and a steep voltage drop occurs it is better to change the battery as failure to do so could lead to a potentially catastrophic battery failure.
Reported by: fast-lad