Femitu 1-8s Lipo Battery Tester Low Voltage Buzzer Alarm Rc 2 Pcs

Works great. Loud enough to be heard while flying, scary loud when you first connect the battery. I usually put my finger over the horns as I plug in the battery to reduce the noise. Also the LEDS are very bright, as I do not use them and I got tired of them blinding me when I plugged in the battery, I put some thin duct tape over them. Overall though, the unit is really great. Basically, you set the voltage alarm to a specfic voltage, I set mine to 3.3 volts per cell. As we all know, your battery voltage will get lower and lower as you fly, but what is more important and interesting is that your battery voltage will sag, or drop markedly and temporarily under load or hard throttle. As you run the battery down, the voltage will sag lower and lower under throttle, until it sags to 3.3 volts under throttle, which is when the alarm will sound very loudly until you back off the throttle and the battery voltage recovers a little bit. This is the time to land before you damage your batteries. Normally when my alarm goes off under hard throttle, if I land right away and check the voltage, I see that the resting voltage (no load) is about 3.7 volts per cell.

Beeper latches once low voltage on any cell is hit and will continue to beep until it is disconnected. It does not stop beeping like the earlier model of this did. I prefer the early model the constant beeping is very loud witch is a good thing if your plane is at a distance. I bought this because of the older reviews that say it stops beeping when the voltage recovers. It would be good if the latching beeping was added to the description because some people may want this feature. Cell to cell inaccuracy is what brought the rating to 3 stars, I measured up to a .2 volt difference that was not true.

It has made my FLYING more ENJOYABLE ! With lipo voltage buzzer in each of 1 of my 5 RC Planes I don't worry about how much time do I have before I have to land or face a DEAD STICK LANDING or a possible CRASH. Each of my 5 planes have their own flying time but with LOW VOLTAGE BUZZER always SOUND and I realize it time MAKE A SAFE LANDING. For the cost of the BUZZER is worth cost rather than being faced with a FIXER-UP JOB or worst BUY A NEW PLANE for a replacement. The LOW VOLTAGE BUZZER, how did I ever fly with out it any thing I ever flew !!!

Works on my Quads...This item is not a charger! It reports by LCD display the voltage of each cell. A 2S cell will be displayed as on three (3) different ways, total voltage of the battery, voltage of cell #1, and voltage of cell #2. This rotation or reading is repeated continues endlessly. When a cell voltage drops below a set point, an audio aswarm will sound, loud enough to to hear about 20 yards.Your 5 cell will be read as total battery voltage, and each cell voltage, and will alarm when the one of the cell voltage drops, below safe for the battery, level244 Jake244 Jake

Pros:LiPo SafetyPeace of MindAdjustable voltageCons:Shipping timeThis works about as well as any other Lipo monitor, it has a very loud buzzer that can be heard from far off, even over the drone of a multi-rotor. Th only con I can think of is the long shipping time, but I can understand if because it is at such a low price point and comes from China. Just be aware that it will take a while to get to you.

don't expect great accuracy with these, out a batch you will be lucky if you get two that read the same voltage on the same battery. Take the results with a grain of salt and give yourself some padding if using them for an alarm. I only use them on the field for a quick view knowing it is not 100% accurate. Use telemetry for lipo voltage instead of relying on the alarm on this

I love these things. They work well and they are a necessity if you use lipos and want to be sure you get the most out of them. I always fly my larger stuff with these attached and set it to 3.7/cell. That way, once a cell gets to 3.7v, it'll start beeping loud enough to hear for me and I've got time to land and keep the lipo within the safe range, and so that after a 10min rest, they'll come back up to a good 3.8. I highly recommend these and if you don't have one and use lipos, I think you should get one.

This simple little item tests your lipo batteries. It is very easy to use. Just match up the ground socket with that of the tester and the unit shows total capacity and runs through each cell showing their current status. The unit will test up to an eight-cell battery. The beeping it pretty loud so try not to use it when everyone is asleep.