When I connect the battery for the first time to a newly built FPV drone, I wait with bated breath to see if everything is OK and no smoke comes out. Short circuits due to wrong wiring and bad soldering are the most common problems in DIY drones, and they cause serious damage to sensitive electronics. VIFLY ShortSaver V2 can detect these problems and disconnect power in less than 3ms.
In a nutshel, a “smoke stopper” is a safety device used in electronics and electrical circuits to prevent damage caused by excessive current, wrong connections, or a short circuit. It is designed to protect the components from potential smoke or damage that could occur in the event of a wiring error or other electrical problem. A 1500mAh LIPO battery with a 150C discharge rate can deliver up to 225A when short-circuited, similar to a welding machine’s power. Trust me, there will be flame and melted metal, not just smoke.
In the past, many used a light bulb to indicate any short circuit, but this technique does not cut off the power completely, and the expensive components can still burn out. The second-generation VIFLY ShortSaver monitors the amount of electricity going from the battery to the drone and cuts off power if it exceeds a certain amount. The V2 has 1 Ampere and 2 Amper threshold modes to match idle power usage.
VIFLY ShortSaver V2 review
Disclosure: I received this short-circuit detector device as part of a product review collaboration with VIFLY. Specs and quality may vary according to the manufacturer’s reliability, so I cannot guarantee that you will get a product that performs exactly the same as seen in my article.
The ShortSaver V2 comes in a zipped antistatic bag with an instruction guide included. The PCB measures 42 x 30 x 10 mm and is protected by a transparent heat shrink tube -very minimalistic design but cost-effective as well. On Thingiverse, you can find STL files to 3D print your own case.
It has XT60 and XT30 connectors on both sides. The output (drone) plugs are on 5cm wires, and the input (battery) connectors are soldered directly into the main board. It has three status LEDs and two buttons (power and mode) on the front part. On the back of the PCB is a printed table showing the status of each LED.
VIFLY Short Saver V2: LED coding
|Status||Current (BLUE)||Detection speed (Yellow)|
|Green: Power ON/OFF
|X: 1A mode
O: 2A mode
|1 blink: 3ms (SC) | 15ms (OC)
2 blinks: 5ms (SC) | 20ms (OC)
3 blinks: 7ms (SC) | 30ms (OC)
- [Completely cut off the current flow and prevent the “killer magic smoke”] Other kinds of smoke stoppers like light bulbs or resettable fuses just limit, not stop, the electric flow and leakage current may still damage your components. The second-generation VIFLY ShortSaver adopts an electronic fuse to completely cut off the electric current into your RC build if a short circuit or wiring mistake is detected.
- [Super-fast reaction/protection time] The ShortSaver V2 disconnects the power to a device that drew more than the switchable 1A or 2A threshold within just 3ms. The fast response time is crucial to save the electronic parts.
- [Power ON/OFF Switch for Easier Receiver Binding] Holding down the bind button and connecting the LIPO battery simultaneously can be challenging when you have only two hands. The new version of VIFLY ShortSaver added a power on/off button that can make your receiver binding much more convenient. It works well also for ELRS receivers which need to be powered on/off three times to enter into bind mode.
- [Dual current mode 1/2 Amp Threshold Selector] For small-size drones with more sensitive electronic components, you can select 1 Ampere, and for large builds 2 Amps.
- [High-quality battery connectors] VIFLY ShortSaver 2 uses Amass XT30 and XT60 connectors on both ends (IN-battery)/OUT-drone). You can even mix them. Testing XT60 drone with XT30 battery or the other way around.
Before receiving the VIFLY ShortSaver V2, I used a digital multimeter to check if everything was wired and soldered correctly in the drone I built. Till now, it worked well for me but took lots more time than using this dedicated device. As it does not completely cut off the electric current, I never used a bulb smoke stopper for short-circuit detection.
The VIFLY ShortSaver V2 is completely plug-and-play. You just need to set the electric current limit (1 or 2A) and plug the connectors. I got a false alarm only with my 7″ drone -probably when the ESC initialized itself exceeded the 2A limit.
Besides short-circuit detection, I also use the Short Saver for binding. It can conveniently power ON/OFF the drone (radio receiver).
Pricing and availability
The ShortSaver V2 can be purchased from ViFly online store for $12.99. ViFly accessories can also be ordered from platforms like Amazon, AliExpress, eBay, or many popular RC retailers.