Plan C | Fatshark 18650 Battery Case Reverse Polarity Protection Mod @Plan-C | Uploaded August 2017 | Updated October 2024, 1 hour ago.
This video shows how I modified my Fatshark 18650 battery pack to provide reverse polarity / reverse voltage protection.
It is very easy to insert the 18650 batteries the wrong way around. As far as I am aware, there is no protection against this inside the goggles themselves (if there is I have yet to see confirmation) and definitely none inside the battery case.
This mod uses Joshua Bardwell's 9v step up Pololu regulator hack as a base and adds a cheap diode (1N4001) on the voltage in feed to the regulator. Everything fits inside the original case. The result is that the goggles are protected from reverse voltage.
The fan connector and the battery indicator board on the battery pack are not protected though as the battery indicator needs to see the real battery voltage ... so don't do what somebody suggested to me and click the battery check button on the case to check if the batteries are in the right way! If you do, you will blow the led indicator like I did. I show how to fix this in the video too.
The downside to this mod is that the buzzer in the goggles will not warn of low battery voltage anymore because they will be fed 9v until the batteries are dead. This means you could accidentally over-discharge the batteries and kill them! The only indication will be the leds on the battery case. The upside to this mod is more flight time and peace of mind.
Mods are at your own risk.
Good luck all.
This video shows how I modified my Fatshark 18650 battery pack to provide reverse polarity / reverse voltage protection.
It is very easy to insert the 18650 batteries the wrong way around. As far as I am aware, there is no protection against this inside the goggles themselves (if there is I have yet to see confirmation) and definitely none inside the battery case.
This mod uses Joshua Bardwell's 9v step up Pololu regulator hack as a base and adds a cheap diode (1N4001) on the voltage in feed to the regulator. Everything fits inside the original case. The result is that the goggles are protected from reverse voltage.
The fan connector and the battery indicator board on the battery pack are not protected though as the battery indicator needs to see the real battery voltage ... so don't do what somebody suggested to me and click the battery check button on the case to check if the batteries are in the right way! If you do, you will blow the led indicator like I did. I show how to fix this in the video too.
The downside to this mod is that the buzzer in the goggles will not warn of low battery voltage anymore because they will be fed 9v until the batteries are dead. This means you could accidentally over-discharge the batteries and kill them! The only indication will be the leds on the battery case. The upside to this mod is more flight time and peace of mind.
Mods are at your own risk.
Good luck all.
