It is sort of dangerous, and typically not worth it doing cell surgery.  Please get another battery. 

If you brought it online with some warranty, you should have contacted the seller BEFORE opening up the battery like this.  Remember that you can check individual cell voltages and total voltage without opening up the battery like this, just using the available connectors.

Good to see that at least the problem is now identified to be our initial suspicion about the battery voltage itself.

I am absolutely new to electrics and my first shock  .

Please suggest my current battery(so-called fresh and new [betrayed by battery :']) is 11.1 v, 1800 maH 20C

if I go for a 30C with 2200 mah would that improve the performance? 

I understand by increased Mah (from 1800 to 2200) ..its performance time will increase but How does 20C or 30C is different?

I have Esky charger received with this RTF, so if I purchase a new battery do I need to buy a new Charger too

More "mAH" = more flight time at the expense of more weight. Not sure what this heli will take, need to investigate.  Guess others who have extensive experience with this model will comment.

More "C" = more current to the motor/ESC when needed, which can be roughly translated to more power/higher headspeeds (assuming your motor and ESC can demand/handle the same safely).

Wait for others to comment on suitable battery, or look around on the web for battery recommendations.  Remember that batteries of same mAH from different brands can vary in weight !

I have a belt cpv2 2.4 GHZ & I am using Turnigy 2200 mah batteries without any issues at all  -in fact i have one original Esky battery - 1800 mah & 3 Turnigy 2200 mah batteries - all work great
Regards

It is not a huge difference in mAH between 1800 and 2200, but then these helis are not built to haul a lot of extra weight either. Since you have confirmation from Bill, you can proceed.

Actually buying same from HK. Wot is the possible use of current battery I have?

Same means 1800 Mah and 11.1

Current battery is effectively 8.5V 1800mah with a weight of 11.1 V. Is there any way I can experiement and try to activate the sleeping cell? I have nothing to loose in this battery..

One cell is short circuit in three cells. How to find where the short circuit is?

red and blue wire when checked with mutimeter (show no vots and when checked for resistence show zero)

If I somehow undo the short circuit, is it possible to revive the Lipo?

Just make the cell separator between Cell 1 & Cell2 a little space So that the the terminal got separated (if shorted earlier) with the two body. or give insulated spacers between cells. then charge with +ve to red and negative to blue only from separate charger.

If again, still gets shorted, just de-solder the red and blue wire and the cell-1 from PCB and charge separately. you surely got charged and check the voltage build up.

If still the cell shows short circuit, or the terminal voltage be zero, give shock to the cell by giving appx 40-60 Volt, 5A DC Source to terminal momentarily (just terminal flashing) so that if any micro short-circuit in any foil portion may blow up and the rest cell may take charge. 60% of dead cells got live with this method. But remember, if the cell got larger in shape for internal gassing, just replace the cell.

I Think just de-soldering and re-soldering may do the trick as the excess solder mark seen over PCB. Please keep in mind, the full capacity current you have to allow through the soldered lead also.

In picture, the insulated terminal shown which may short-circuited during soldering.

Thanks

Thank you so much Kalyan for your valuable suggestion. Now Postmortam of the battery is on you can see in in the picture there is no visible short circuit. Will try to resold it but I am not sure even that will solve the problem because, shortcircuit is not visible outside.

Is it possible that the cell is internally dead and hence it shows no resistence on multimeter?

Well,

As per Anwar Sir if warranty available, just claim it. Else you can go yourself.
 
Just measure milivolt between red and blue. If zero, thenmake the multimeter in Contuinity buzzer mode and check in both polarity for at lease a minute. One side, it will continue to buzz and in reverse side it start with buzzer but suddenly it will stops and potential growing starts. Keep in that mode for a few minute and measure the milli/micro voltage developed across the terminal. You nee Polarity only. Check thet it was initially soldered in reverse polarity.
As sen from the picture of you, there is only printing over pack that indicate the polarity and the soldering person makes solder the cell with PCB with correct printing side. (Cell1 reversed, cell-2 & 3 forward soldered). Just reverse the polarity and charge.

If both side starts buzz continuously then follow the procedure.
===============================================
The cell pictures looks clear. Now, just de-solder out the cell from PCB. Keep it in deep fridge (In Plastic wrapped for an hour+-) so that it become cold. Now measure the potential difference of your cell with milli/micro voltmeter (Multimeter in milli/microvoltmeter range).

Case-1
======
If you get a few millivolt reading, it may be survived
Just watch the +ve and -ve terminal and charge with the polarity. Actually, as the printing on the cell printed in wrong polarity, it was soldered in wrong polarity. Just charge with correct polarity and resolder with correct polarity.

Case-2
=====
No Millivolt reading you got but found absolute zero. Chances are less to survive.
Look, here again the polarity may be wrong. Just make reverse charge for a few second and check if any potential build ups or not. If the foil packing of the blue covered area punch makes short circuit, you have to make mechanical surgery to the foil seal. Better, purchase similar one cell (Even if you can buy single cell of less/more capacity as you have balance charger but bottleneck capacity will be lower one) and fix it to the PCB. but you may puncture the foil seal and isolate the two terminal electrical foil connection from one another and repeat same deep fridge procedure. You afterward, seal the mouth cut with just tape

Great Observation  , thanks. Will do this. Please advice, can I use a normal 12 V adapter to charge this cell i.e. connecting a this cell's positive and negative with charger's positive and negative or I need someting different?

Now I realise that why the balance charger was showing fault in battery when I was initially charging it. But I somehow manage to charge this battery with that balance charger. ( I am sure that was an unbalanced charging)

You are absolutely right, two cells are same position and one cell is soldered in wrong direction and thats the reason of shortcircuit. I wonder this cell is wrongly soldered for a long period is it now possible to recover this dead baby?

So much said about LIPO's dangerous and flamable character.... a cell soldered in wrong direction and I have been chargin it and discharging it... How can a company be so irresponsible in dealing with LiPo soldering?

Yes,
you can use a normal 12 volt adapter to charge.

Actually the excess voltage (PS Voltage - Cell EMF) got wasted in the circuit resistance (Wires, Transformer secondary winding, Cell internal resistance (Though Minimum) and the Diode resistance too as it will operated in higher current rating. Just add a current limiting resister in series.

Let you charge with 1 Amp. Therefore (12-4)=8 Volt drop across resistance.
R = 8 Volt/1Amp = 8 Ohm.
Watt= V*V/R or I * R = 8 watt.
Therefore you can use 8 ohm or higher resistance of wattage (Calculated value for the resistance).

I prefer just add the cell in series with your hot wire cutter if Power Supply is DC.

But don't go in the calculation details. Just give a flash or a few second supply directly from your 12 Volt (Any volt higher than 4 volt) to the dead cell. in both the polarity and check the potential builds up or not Keep in mind that as a dead cell, it has no storage charge that may burst the cell like other cell. So you have no fear.

In any problem contact me directly to my cellphone no. 09231657193.

My drawn picture is given which is right and should be as per PCB. But i am confused about the stamping on LiPO cell itself.

For experience, I have shocked one shorted NiMH cell with 40V,5A PS and got survived. I know the polarity for me which is controversial in your case. So, just charge Blue with Positive and Red with negative and check if voltage building or not.

Hope your success.

Thanks.

Note: Plz, dont call me tonight from 10PM to 8AM as i will be in train from Kolkata to Siliguri and signal may fail.

thank you Kalyan for telephonic guidance and your suggestions. Unfortunatrly the cell was dead. I tried charging it for more than an hour with a 12 volt charger. With right polarity it didnt catch the charge and when I reveresed polarity within 5 minuts my 12 volt charger was very hot and i thought its coil was at the verge of burning. 

The cell was dead and didnt survived. 

Anyways hav already ordered a new battery. But this experiment was a learning one.

Learning from the above exp:

a) Whenever any RTF is not giving its full performance, before jumping into ESC or other electronics we should first check the battery.
b) Battery if not giving the voltage as per required norm shows that cell might be faulty.
c) If the cell is faulty and you have already performed some cycles of charging and discharging dont expect that faulty to survive (in my case the cell was soldered in wrong direction. i.e. wrong polarity.
d) Dont open the batter as I did, as there may a possible warranty that you may claim. (In my case I dont expect a company based in US will give a new battery). Try and find the fault without opening it.

It is always a good idea to order a spare battery or two(and some spare parts as well) along with your new heli, 'cos anyway you are gonna need 'em.

No matter what charger you have, there would be a ground time of atleast half an hour between charges unless you've more than one battery. Hence keep a couple of batteries at least . That way, you don't have to open up the battery to judge if it's dead (assuming the second battery is good) and claim for warranty.