Hey guys. I got question and wondering what would of caused this. I went out for my second flight on this my first quad build. I flew for about 2 mins and my transmitter went beeping crazy and rx alarm going off. Landed and noticed my battery was pretty warm. Checked the voltage and all 3 cells were under 3.00 volts. Being cautious i hooked up the battery to 12v light to drain it down for disposal and it took 1 min. Connected 2 different voltage checkers and nothing. Seems it was drained completely. I knew something wasnt right then. Im wonder what could of caused this or just a bad battery. Im using turnigy i6 tx and rx. Hobbymate 2204 2300kv motors. Hobbymate blheli 12amp escs. A QAV 210 frame. Matek Pdb. And the battery was tattu 75c 1300mah battery. No fpv gear just flying LOS for now. Im new to quadcopters so any info is helpful. Thanks

Not to state the obvious, but was the battery charged to begin with?  Did you check it before you flew?  Battery 3S/4S?  Weight of the quad? You say you're just starting out, so I am ASSuMEing that you were not flying very aggressively?  Were the motors warm (hot).  Could be a bunch of things and I am sure some of the guys will come along with more knowledge then I....I was just throwing a could of obvious things out there.

Thanks for the reply. I didnt take account into weight of the quad. Being new didn't think of that. Motors were cool and escs. And your right i was just buzzing it around a little nothing aggressive at all. Now that i think of it battery was not fully charge it was just at storage voltage 3.80 per cell . I just making some changes to flight controller and took it out for a quick test and thats when it happened. Didnt think the battery would discharge that fast. It may have been my fault then. Im used to ground rc vehicles and batteries last long. Its ok i learned a lesson today. 

A fully charged battery will be about 4.2 v per cell.  Make sure it's fully charged and that should make a big difference.  Good luck!

I made the same mistake when I first got into multirotors. It surprised me how quickly the batteries emptied compared to my RC cars.

Yea definitely did not know it was drain that fast. I learned thought today. Will get a new battery and be more careful next time. I agree there is big difference in RC cars. Hopefully i didnt damage anything with the electronics, motors and escs though.

(11-Sep-2016, 02:10 AM)rcandvideogameguy Wrote: Yea definitely did not know it was drain that fast. I learned thought today. Will get a new battery and be more careful next time. I agree there is big difference in RC cars. Hopefully i didnt damage anything with the electronics, motors and escs though.

It shouldn't have damaged anything else. I was used to 5000mah batteries before multirotors which used to give me at least 20 minutes of run time.

Same here i Have a 5000mah 2s lipo i run in 1/10 cars and small 1750 2s for my 1/18 car and both last way long. I was think of getting a 2 batteries for my quadcopter. Just swap them out and get more flying time.

Multiple batteries with swapping between flights is the way to go.

I was wondering another thing too. How do you guys monitor your batteries when flying. I see some flight controllers and pdb have a low voltage alarms. Mine doesnt and i know some use a timer on there transmitter but mine doesnt either. I was going to use a voltage alarm and a digital timer. Would setting it to 3.5v per cell be ok or is a little higher better or a little lower be ok too?

I got an on screen display (osd) which tells me the voltage, actual current, current consumed and timer. I land when I see that I have consumed about 80% of the battery capacity, or 60% capacity if I don't want to storage charge when coming home

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Bigglesfpv recently reviewed a pdb with osd which is quite good and simple: http://intofpv.com/t-matek-hubosd-pdb-w-...r-dual-bec

Thanks Ill look into that. Im not using fpv gear yet but when I do an OSD will be great

if not using osd yet, go for lipo alarm... you plug it in the balancer and it will go crazy beeping when to low,
unless you have the buzzer on the quad then you can use it and FC voltage meter.

(11-Sep-2016, 10:15 PM)rcandvideogameguy Wrote: I was wondering another thing too. How do you guys monitor your batteries when flying. I see some flight controllers and pdb have a low voltage alarms. Mine doesnt and i know some use a timer on there transmitter but mine doesnt either. I was going to use a voltage alarm and a digital timer. Would setting it to 3.5v per cell be ok or is a little higher better or a little lower be ok too?

I often use a plug-in alarm, as Grisha suggested. I think 3.5v is a good starting point. For some of my craft, I set it a little lower, but it depends on several factors. You'll get a good feel for it over time. I commend you for being safe and tossing your battery, but if a lipo is drained slightly under 3v/cell, it is generally still safe to use. Allow it to cool down, charge it at a lower rate, and keep a close eye on it while charging. Make sure it doesn't begin to get warm. I hope I don't get blasted for suggesting that, and I do encourage you to get other opinions/advice. Lipo risks are not to be taken lightly. But I've seen, had, and read of many recovered batteries without serious detriment. However, you may notice some loss of overall capacity or output. Happy fIying! Learning multirotors & fpv has its challenges, but the journey is a lot of fun for most of us.

I'd recommend 3,7 you still have some time to come back

As for recovery what i did and for sure this wasnt safe but it worked so dont try it at home... Do it at your friends house

Discharged battery didnt want to be charged on lipo program as the cell v was too low.... Resolution, turn on the nimh charging program, go outside put battery in flower potceramic not plastic in case of burn, charge with 0,5 a for few minutes, check cell v. When over 3,3 move back to lipo program and balance charge them... Doing this have an eye on the battery puffing or bursting in flames possible.
I've managed to rescue few batteries this way.

And if after few miuntes of charging your cell is 0 v or droping very fast... Dispose this battery as this cell is dead or useit as power for other devices ie goglles