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documentation:booster:start [2022/05/17 09:38]
gregk
documentation:booster:start [2022/05/25 10:02] (current)
gregk
Line 404: Line 404:
  
 Why is my remote control battery draining so fast? The aircraft batteries are intelligent, and once you turn them off, there is no power drain caused by custom mods like the booster boards. The remote control is different. The relay output contacts get power directly from the battery, and the relay coil is powered from a switched source elsewhere in the remote. The relay coil power should only be active after turning on the remote control. To prevent mistakes, use a multimeter to check the voltage going to the power modules is zero volts when the remote control is not turned on. Why is my remote control battery draining so fast? The aircraft batteries are intelligent, and once you turn them off, there is no power drain caused by custom mods like the booster boards. The remote control is different. The relay output contacts get power directly from the battery, and the relay coil is powered from a switched source elsewhere in the remote. The relay coil power should only be active after turning on the remote control. To prevent mistakes, use a multimeter to check the voltage going to the power modules is zero volts when the remote control is not turned on.
 +
 +===== Booster Board Myth Busters =====
 +==== RC Battery Drain using relay with power off ====
 +
 +Some have commented that their RC batteries are getting drained even with the RC turned off. Let us analyse this myth.
 +
 +If we look at the wiring diagram in section 3.2.2 Relay Switched Power, the output voltage from the relay to the boosters is not connected when the relay coil is not powered. The instructions in section 5.2.3.2 Remote power connection - Relay - Generic ask you to connect the relay coil input to a power source that will only be active when you turn on the RC. In other words, when the RC is off, this connection point should not provide any power.
 +
 +If you correctly connect as per the instructions, this will draw ZERO power when your RC is off.
 +
 +  MYTH BUSTED.
 +
 +==== RC Battery Drain from relay during operation ====
 +There has been a lot of unfounded speculation that the relay is the cause of all problems, including world hunger. (Well, maybe not world hunger, but let's get to the facts). 
 +
 +The Mavic 2 RC battery has a rated capacity of 2970mah. The battery capacity for other devices will be different, but it is not a significant factor when looking at the other numbers.
 +
 +The specifications for the relay indicate it draws 21.1 ma on the coil at 5 volts. 
 +
 +Doing a simple division, 21.1 tells us that if we only power the relay, it will last for 140 hours on a fully charged remote control battery. But don't forget, that is ONLY if the RC is on. When you turn the RC off, the relay will not draw any current at all.
 +
 +  MYTH BUSTED
 +
 +==== Bypassing the step up or step down modules ====
 +Some people think it is good to bypass the step up or step down modules to reduce power drain and increase battery life. The power modules consume a small amount of power during the voltage conversion, but it is insignificant compared to the booster boards. 
 +
 +We recommend pulling raw battery voltage as a power source. If you pull 5 volts from elsewhere in your aircraft or RC, it may draw more power than that part of the circuit is rated to provide. You could damage other parts of your device, all to bypass a power module. You should only use an alternate direct 5 volt supply in your equipment if you are confident that you can draw sufficient power at the point you are connecting to, and the voltage will remain constant as the aircraft battery drains.
 +
 +  PLAUSIBLE, but NOT RECOMMENDED.
 +
 +==== Power usage for the booster boards in the RC ====
 +There has also been criticism that the booster boards will flatten your RC battery during normal operation. Let's find out how long a booster can last on a regular battery.
 +
 +The rated power supply current is 1200 mA. If this is the only device connected to your RC battery, it will drain a fully charged battery in 2.475 hours. So yes, it will reduce battery life, but not unrealistically. That is the price to pay for the extra range.
 +
 +  BUSTED
 +
 +==== Power usage for the booster boards in the Aircraft ====
 +There has been criticism that the boosters will reduce flight time excessively.
 +
 +The capacity of a Mavic 2 battery is 3850 mAh. For a flight time of 30 minutes, the aircraft is therefore consuming 7700 mA on average. Assuming 1200 mA, the introduction of the booster board will reduce flight time by an estimated 15%
 +
 +  BUSTED
 +
 +==== It gets too hot ====
 +One user has reported "cooking" multiple booster boards because they get too hot. 
 +
 +A radio amplifier will convert power into amplified RF. One of the byproducts of the process is heat. The specifications of the booster boards refer to requirements for passive cooling. What does this mean? It is mandatory to mount the board to allow heat dissipation. During testing (before permanent installation), you must use a heatsink or cooling fan for temporary testing. We found videos of this user testing the board suspended in mid-air without active or passive cooling, which would be the electronic equivalent of running a car engine without oil. Yes, you can cook your booster boards if you don't use cooling.
 +
 +  BUSTED