hello everyone,
i was testing my quad today and noticed the motors slowing down , i remembered that i had not checked the lipo voltage for quite a time ,i checked it ,it was 7.76 v   ,individual cell voltage:
1 cell~3.6v
2 cell~4.16v
3 cell~0
the multi meter showed these values 3.6v ,7.76v and again 7.76v when i tried to check each cell
i think im doomed ,can i do something with this lipo bcoz it was a new one   and was just using it the first time
after reading some of the results of overdischarging , i am even afraid of keeping the lipo at my house ,can it catch fire  
please help me
regards
rohan

if i need to get rid of this lipo ,how can i do it ?,should i try charging it once?can it explode?
please help i cant even sleep , im afraid it will explode while im sleeping

This is unfortunate

The Lipo won't burst. It may catch fire if you try to charge/discharge it.

Such a dramatic "zero" seldom happens. Have you checked that no wire/soldering has come loose? Also, check your charger (for future)

In case you need to dispose of the Lipo, remove the top cover and leave in a solution of salt and water for a few hours. But first do check for a broken wire joint

hi rohan, if you are going to dispose can you send that to me?

i charged the battery for an hour and saw the first 2 cells are ok ,there voltage after charging
1 cell~4.2v
2 cell~4.3v
3 cell~1v
and i think only one cell is damaged ,and i read on rcindia that you can revive a singal cell my a 4.5 dc charger by charging for 1 min to get the voltage to 3v so that the charger can identify the cell.is this right?where can i get a dc 4.5charger
regards
rohan

and akhil if the lipo wont be of any use for me i'll send it to you,and thanx for the arduino code

if you have a charger with usb port and less than 1 amps(computers usb port are not recomended) can be used to boost that single cell

heat must be observed during charging.

can i use a power bank used to charge mobiles

power banks also not recomended, because may your damaged cell's internal resistance is weak then it will become short that ll damage your power bank.

Use a Good mobile charger, Or a external mobile batterycharger.

i have an old sony erricson charger.
specs:
5v DC~850mA
but the miniUSB pin is damaged

yes that ll work.

If the charger is of no more use what it is intended for, Just cut out the USB pin, and use it as a 5V power supply, for little glitches like this

i did cut the pin and can see a solid piece of wire wrapped around in plastic and the plastic is wrapped by fibres of wire
i think the solid wire is +ve and the fibres are -ve . please can somebody confirm

Normally the core should be +ve, But no one can confirm, I have experience with some Chinese chargers, where the core is -Ve , So it is always better to check with a multimeter.             To be on the safe side.

new discovery!
i opened the solid wire and saw a red and a black wire so i assume the fibers are ground,should disregard it right??

im getting frustrated , found a green wire.
so i think im confusing myself and everybody.
finally , 3 wires red,black and green and some fibres around them(not in contact)
now ,please help and thanx sooraj and akhil

Ha HA ,That's funny, Can you post a Pic showing it all, .
Any way, The +5VDC and, GND would be usually Red and Black respectively.
BTW don't you have a multimeter or voltmeter?

have a class so leaving right now ,thanx sooraj for your help ,will check later using a multimeter
regards
rohan

Evening class? Of what ?

i have my VMC(vidyamandir classes) for JEE exam ,there are often doubt classes in the weekdays

i checked the voltage of the charger ,it was 5.12v and i charged the cell for 2-3 min and saw no change,can the cell be dead?
i am now charging the battery with the B3 pro charger to see any change

2-3 minutes may not do the trick always, I had to put one of my mobile battery, for hours !!.
While doing this, you should continuously, measure charging voltage, connect your multimeter probe to battery terminals and charge, the battery, one more thing , keep checking any temperature change in the batterypack, by touching in intervals.   

Rohan, did you succeed in setting up the Hobby king multirotor controller V3 ?. mine sucks  .
Tried everything but the LED on FC board never come on, no ESC beeps..., Can you help ?

the voltage of the cell went from 0.01v to 0.03v in 2-3 min but that can be the error too

charge it for more time see the above post.

yes , just decrease your throttle trim on your transmitter ,then take the throttle stick to down right then the led should come up,to disarm it take the stick to down left ,then do the esc calibration ,last night or you could say today morning :p i tried to lift the quad but then the battery catastrophe happened

if it goes below .5 volts just check its resistance using continuity tester, if it has no resistance then no way to recover.  

continuity tester??what is that?it is a part of multimeter?

That's sad.
However happy that you are a bit ahead of, me , I am trying this for first time today.
Why? my 5th sem exams are going on, waited these much but can't resist to get this on air !! Even there is exam tomorrow

Continuity is in your multimeter, You can also use the low resistance range, Is your multimeter digital?

Measure the resistance of your damaged cell as you measure a actual resister, but consider polarity of multimeter probe matches that of battery.

yes ,and what have you taken EEE,ECE or ME?

ECE, Diploma

i dont get it

What ?

i didnt get this,i havent ever measured the resistance of a resistor

Is yours a digital multimeter? or analogue ?

But, don't bother about it now.., Put it connected to the charger and also connect the multimeter to live monitor charging voltage..., Check temperature change in Intervals.

but sooraj, if the battery is shorted internally then the charger feels as the terminals shorted if that connected to charge and this will be damage the charger.

does anybody know where can i get a battery 3s 2200mah for cheap like under 1k because i bought this one for 1.3k and didn't even use it once,can i remove the damaged cell ,they are at 4.2v

@akhil, that case can be understood buy checking heating up of charger, if battery is short, the charger will heat up like hell, isn't it?

@rohan, where did you bought this? Ask a replacement if you can.
Check PM

If the worst turns out consider hobbysea.com for new battery, they offer original Zippy battery for 1.2K

sooraj my net is down so it will take time to upload ,if you want i can call you
How do i remove the damaged cell without damaging the battery and can i use the 2s 2200msh(if i can remove the cell) to test fly it for a few minutes??

No 2S cell will give only max. 8.2V out, It is no use with big multirotors, Can be used for small higher KV motors. Did you tried charging ?

with which charger the 5v or the lipo one??

With 5v mobile charger. for atleast few minutes or in worst case for hour, don't forget to monitor charging voltage, LiPo temp. , Charger temp lively, 

I gave up on the hexacopter for today, no use discharging the battery, my charger is still on it's way to home through EMS!! expect it tomorrow or Day after. Next try after exam tomorrow !!

ok i will do that,best of luck for your exam

i saw online that we should charge using a nicd charger.are they cheap?

The use of NiCd charger is what we are attaining with This cellphone charger, !!!,
Unlike a LiPo balance charger, A NiCad charger doesn't care the minimum voltage to detect battery, they just charge the battery to threshold level. But a Lipo charger detects a cell only if it is above 3V and if the cell voltage goes below this , a LiPo charger won't detect the cell.
   What we are trying with cellphone charger is to Charge the cell up to 3V so that LiPo balance charger could detect it .

If you are still afraid to charge this cell, give it a rest and take out any old computer SMPS, to check and tune your quad !!

no i tested it with it and am uploading a video(49% done,damn internet connection) but after using it i measured the voltage the first cell is 4.2 the second is 4.3 but the third is -1v ,how is this possible?
the actual readings were 1st wire-4.2v the second wire-8.5v and the third wire-8.38v
how is this even possible??

You are measuring voltage in reverse polarity man !

ok , now you say you have tried the hard way......but I don't think it's not time to discard it yet, no more tries, For now, You may risk it with reverse polarity or some thing PM your phone number, I will call you and help you out tomorrow evening (anytime after 1PM).

i dont think im measuring it in reverse polarity because the multimeter says + if i exchange the wires then there is just a - sign over the readings i think better is to discard the cell ,can you guide me through it ,will pm you my no. you can call anytime dont have school or classes tomorrow ,i will get a new battery tomorrow for the quad as i will have to buy it anyway
i dont get it people said the battery after discharging becomes puffed and heated ,this one was cold and the 3rd cell looks a bit puffed
regards
rohan

Is it puffed? now?
Ok, A idea I got from Kalyanprodhan sir, pack your battery water proof and put it in your refrigerator- until my call tomorrow



Hey no, I am not trying to fool you  !!!!, I have my Two LiPos in my fridge right now, Kalyan sir gave this idea, he says fridge is best to prolong this unknown alien's life ime .

i have read his post, will do it, cooler or freezer?

I don' think freezer, Because I don't whant ICE !!, I only need my batteries back when I take it out,

Cooler will DO :8

On Load when the Cell EMF < I x R drop where I = load current and R = Cell Internal Resistance, the terminal voltage shows reverse.
For an rechargable cell, asfter complete zero, Active materials can develop in reverse polarity. And then only even after disconnecting of the load, you may see reverse polarity of the cell with respect to original condition.

hope the result is not blowing up my refridgerator ,i cant do it my mom said "no" and dad said "you want to blow the fridge up?" :p

@sooraj the video has been uploaded ,sorry for the recording ,had to do it using my phone
https://www.youtube.com/watch?v=fvzMcnVRVv8&feature=youtu.be
regards
rohan

No I don't think it will simply blast by freezing inside the fridge,
PS: I put it inside my fridge with out mom noticing, If she saw she may throw it out!!

LET ME TRY i DON'T THINK STREAMING WILL BE KNIFE ON BUTTER WITH A 2G CONNECTION !!

Oh my luck, It is only a 15min wait , to download on 480P

why not watch it ,its just 1.5min or download in 240p saves time

Hey wht is it's content?

setting up the hk board ...if you dont get it search "hk multi rotor fc board v3 flight test" ,there will be 2 videos check out the 2nd one,it is the setup

did it work??

Nope,
Tried many ways, now transmitter battery down.
BTW , where did you get this flight control board.?

got it from sundaram sir ,got it in the clearance sale
which FC are you using??

HK multirotor control board V3 , the one with atmega168PA microconroller.

@ sooraj and rohan123
the discussion is deviating from actual topic

@sooraj the one with the 168PA MCU is v2 .check online
@akhil sorry ,didnt want to start a new topic for a small discussion,and i am now soldering the wires and will keep you updated about the progress
regards
rohan

yup, Rohan, I will contact you via, phone.

However, I just left the hobbyking board setting up multiwii flightcontroller on the breadboard right now.

Mission accomplished ,the 3s 2200mah lipo is now a 2s 2200mah ,will discharge it and will charge it again to see if it works fine ,current voltage~8.47v ,thanx to sooraj and akhil
@sooraj i thought you had an exam :p ,ok call me whenever you want my no. is 9953971698(rohan sakhuja)
@akhil thanx for the advise ,and after i am done with this lipo i will send it to you positively. and if you want any electronic stuff ,a seller in chandni chowk is my friend so he gives me discount on electronics ,i can get it for you ,just pm me
regards
rohan  

have a question. can the 2s 2200mah battery be able to lift my quad upto 1-2 meters ,want to do some testing .
and for to be safe in the future at what voltage should each cell be discharged(3.7v or 3.3v)?

No. quad atleast need 3S, rohan.
So you made a 2S pavk , huh? , Keep it if you plan to make airplanes later.

yes ,will keep it for some time ,it will be useful while giving presentations to my robotic club at school
thanx for your help ,bye
regards
rohan

Hey if you are getting in to FPV that cell can be used to separately power FPV system.