Review: ViFLY Finder 2 Lost Model Alarm

by Oscar

Let’s face it, the first buzzer by ViFLY was a bit premature, and they released a few more revisions in a very short amount of time. I wasn’t a big fan of that so I skipped all of them. But it looks like they have finally settled with the V2 so I will check it out and see what improvements they made.

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Check out this shoot out for a whole list of self-powered buzzers.

Where to Buy?

Vifly Finder Mini (3g, 7 hours battery):

Vifly Finder V2 (5g, 30 hours battery):


Here are the spec of the ViFly Finder V2:

  • Size: 24x13x16mm
  • Weight: 4.9g (same as V1)
  • Volume: measured to be 106dB (same as V1)
  • Battery: 80mAh – 30 hours run-time
  • Input Voltage takes 4.5V – 8.5V

In the nice plastic box comes with

  • 3-wire cable
  • Cable tie
  • Manual

Connectors are the same in V1 and V2.

ViFly Finder 2 Buzzer Improvements

To sum it up, here are the major improvements from V1:

  • Added onboard LED (Very Bright!)
  • Longer battery life
  • Supports PWM signal
  • $2 Cheaper!

The rest of the spec are pretty much the same.

The first big difference is the increased run time. The battery is the same capacity as the V1. They achieved longer run time by changing how frequently the buzzer beeps, from merely 6 hours in the V1, to 30 hours in the V2. I think that’s a much better approach to take.

I suggested VIFLY to add a bright LED when I was reviewing the first version, in order to provide both visual and audio aid, and they did it! They even took it a step further and added a light sensor, so the LED only flashes when it’s dark. This will help tremendously when searching for your model at night. LED won’t light up in day light in order to save battery. (you can check if it works by covering the light sensor with your fingers, it’s located next to the connector)

Here are the locations of the components.

Finally, the ViFly Finder V2 is probably the first self-powered buzzer to support PWM signal. It’s perfect for models that don’t use flight controllers, such as wings and RC planes. You can connect this buzzer directly to the receiver. I am going to use this on the S800 FPV wing I recently built :)

Closer Look & How It Works

There are 3 wires you need to connect: GND, 5V (Buzzer+) and BZ (Buzzer- or PWM).

The buzzer and LED can be activated by a switch on your transmitter (just like setting up a normal buzzer in Betaflight Modes tab). For PWM signal, 1500-2000 will activate the buzzer and LED. You might want to setup failsafe to output this level on the channel when signal is lost.

When power is lost it will be activated automatically:

  • First 40 seconds – beeps in low volume (around 96dB)
  • 40 seconds to 2 hours – beeps every 4 seconds at full volume (106dB)
  • beyond 2 hours – beeping frequency reduced to every 10 seconds

The built-in battery gets charged when the buzzer is connected to 5V. So you don’t have to worry about taking it out of the model and charging it separately. However It can take up to 90 minutes to fully charge if it was previous discharged, so make sure to leave it connected long enough when you first setting it up.

Not only it’s now useful for long range quads, it’s also great for wings and RC planes. You can hook it up to flight controllers, or connect it directly to a PWM channel in the receiver. Great!

However it’s still quite bulky just like the V1. While it’s fine for builds with lots of space, it can be challenging to fit in micro quads. For tiny self-powered buzzers, I’d recommend the Hell Gate (the smallest, expensive but original idea), or the FullSpeed Lucky box (cheap).

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Bob 29th October 2023 - 11:15 pm

There is NO way this buzzer will be activated with a switch when wired to the BZ+, BZ-, and GND. Not on my SpeedyBee F4. Prove me wrong. <;-)

Patrick 5th December 2023 - 5:46 am

I just ran in to the same issue with me Speedy bee F7
You need to use
Make sure B- and B+ is not reversed

Patrick 22nd March 2023 - 9:42 am

Do you know if i can have a buzzer and the vifly finder connected in parallel ?
Thank you

Safrudin 9th April 2021 - 12:56 am

I connected to Ground, 5V, Bz-
And I set a channel to activate in the PWM range 1500 to 2000.

But strangely this thing strat beeping even I don’t enggage the switch.

Any idea ?

Matthew Morgan 12th September 2020 - 12:40 am

Yep I’ve bought a total of 5 three of them are dead oh, now I’m looking up some information on how to install a new battery probably one that maybe is twice as big

Andy 15th February 2020 - 1:20 pm

@Simone, Do this USB powering works? Did you test?

My Finder buzzer does not start beeping when I unplug battery. Everything all works well but not start “Lost drone beeping” What would be wrong? Battery of finder is 4.2V and it seems to charged when connect battery, but still not start Lost Drone beeping. Some betaflight setup, or broken component on finder board?

Wayne Patterson 27th December 2019 - 10:49 am

brought one of these but was dead on arrival. For some reason the small battery would not charge. In my case was a total waste of money.

Kevin Moorehouse 7th June 2019 - 11:01 pm

The VIFLY will loose charge and drain its battery if left plugged into a RX. If you are lucky a charge with a battery hooked directly will recharge it, after some time. I had 5 ViFly Finders, this worked on 3 of them the other 2 are trash. This should be stated in the directions to disconnect after use, if possible with some installations.

Simone 16th April 2019 - 7:30 am

Is it wrong to connect your finder 2 to 5v USB?
So I can change it while the quad is connected to the pc too

Patrick 5th December 2023 - 10:00 pm

I connect mine to a USB cable, + and – and charged it for the first time I set it up