I could reach to the balancing of CG of the plane, before that my ESCs was burnt.

I think the voltage might be wrong....
Are you using Li-Fe??
If not check the voltage from a shop...

I am using LiPo 3S (11.7v) Battery.

11.7??

What is the length of the battery to ESC wires ? Long wires can damage the ESC,  if no !ow ESR capacitors are added.

Long wires of which color ?  Any specific color which can damage esc.

Can u explain how long wires damage esc without using "if" in your explanation.

Copied from another forum.......

The voltage is like water running through pipes on it's way to a faucet (the ESC), when the faucet is wide open you have water running through it at a normal pressure. If all the sudden you slam the faucet closed, the water that is already in the pipes moving has nowhere to go and is carrying momentum, builds up pressure, and sometimes causes the pipes to bang momentarily, and then pressure normalizes. The ESC works much in the same way, when you slam the throttle closed, the voltage in the wires that has already left the battery has nowhere to go since it will not be used. It builds up "pressure" against the ESC in the form of voltage spikes, sometimes very high. The ESC has capacitors on it that absorb those spikes, but if you add additional length, the voltage spikes can exceed what those capacitors are able to handle, and over time may fail, allowing the higher than rated voltage to enter the ESC and potentially do damage. To combat this, you need to add, 1 additional capacitor for each 4"-6" of battery wire you add.

https://www.rcgroups.com/forums/showthread.php?952523-too-long-battery-wires-will-kill-ESC-over-time-precautions-solutions-workarounds

This post explains it more......

This might be a layman's explanation of  voltage spike but whoever has read electronics / electrical will consider it absurd explanation.

Length of wire is nowhere related to spoiling ESC. ( when you cut the voltage the switch is in ESC not at the battery )

However what can matter for a efficient transfer of energy ....
1. Wire thickness
2. length of wire ( I am talking of efficient system, ESC will not blow due to length. Here I mean the resistance of wire )
3. you can have battery to ESC wires as long ( correct thickness - wire Gauge) but keep the motor to ESC shortest possible.
4. good solder joints. ( I don't recommend putting connectors)

regds
Saurabh

Too long battery wires will kill your ESC over time!
Voltage spikes higher than battery voltage will destroy components and/or the standard input capacitors (large cylindrical thingies in thin colourfull shrink wrap) will be destroyed over time because they get warmer/hot. Using thicker wire will not help, it's a wire inductance problem, not a resistance problem. See Lenz's law. Inductance is what makes sparkplugs spark, 15-25kilovolt.

This goes for all makes, they all use the same principle (except SLS controllers, they use sinusoidal commutation instead of trapezoid and tested 150m extension without extra capacitors). However, lengthening the motor wires may lead to radio interference. Give the three of them a twist to prevent this.(copied).
 Original post -- https://www.rcgroups.com/forums/showthread.php?952523-too-long-battery-wires-will-kill-ESC-over-time-precautions-solutions-workarounds

Nice Link, thanks for sharing.

I learnt something today. I doubt how many of aeromodellers take care of it.

May be most of us use low current applications and decent wire length which are handled with the stock capacitor in ESC.

One post from the same thread below explains.

So if too long wires damage it what is too long actually...

Few days ago, pop sound comes from my diy quad. Today, one motor is not running properly and esc are much hotter and motor also much hotter than other motor then i replaced the esc with new one and motor is working. This means my esc is brust?

Normally 4 inch battery wire and 4 inch esc wire so total 8-10 inch wire length is compensated by the stock cap on esc. If you are going longer than this you should consider extra cap basis thumb rule in rc group thread.

This might help someone using newer ESC with braking.
https://discuss.ardupilot.org/t/dshot-reliability-and-wraith32-v2-esc-fire/29619/3

Perfect, as most points given, perhaps it could even be ESC faulty as it heats up