RC India

today my plane meet with a serious crash and after inspecting that what i find is this.so i am a bit scared to use these lipo's .so i request all the forum members to guide as to,should i use these lipo or not as these were the new ones and were used for about 9 -10 flights only. :( :( :(

Check for the Lipo very closely. Hope they have not been puncthured.

Incase they have bloated, discard them immediately. They have a potential to catch fire...

For discarding...
1.) discharge the lipo
2.) cut the discharge cable connector (ensure you do not short them while cutting the connectors.)
3.) prepare a salt solution in a mug (salt + water)
4.) Immerse the battery in the solution overnight.
5.) you can now dispose the battery in normal waste.

Unfortunately, the battery itself is out of focus in most pictures  :(

Looks like it can be used (although discarding is the safe option).  If you have a cell measuring thingy (something like this (http://cgi.ebay.in/Lipo-Monitor-4S-A-must-have-for-all-lipo-users-pm-4-c_W0QQitemZ150368071429QQcmdZViewItemQQptZLH_DefaultDomain_203?hash=item2302a2af05#ht_730wt_935)), then you can check if the cells have similar voltages.

Be very careful when you charge it again for the first time. Monitor it continuously (both visually, and feeling the temperature).

i met with same incidents a lot of times..
if they are not punctured , chances are more that they are usable, but i wud recommend to test it first as posted upper..
or if the batt is damages, u can still find 1 or 2 cells in good condition. :thumbsup:

From the first picture it does not appear to be a major damage .
Check Voltage if it is OK you can use them.
I have had many such cases and  no real problems.
I am using 11.1V 4300 mah batteries like this for the past 2 years without any problems .
None of the cells in the photo appears to be bloated  but can't say for sure as the photos are out of focus.

So if there is no bloating I will continue using them.

Sai

Bloating alone is NOT the only concern in such cases.  If the area where the connections go into the individual cells are impacted, that could result in lost (or less then prefect) connections.  That is something else to be aware of, and watch out for.

is it okay to strip out the battery pack insulation/cover and check the pack out ?

Not recommended at all.

It is much easier to check the individual cell voltages.  It is simplified by using one of the devices posted earlier.  You can always use an ordinary voltmeter/multi-meter, just be careful not to short the cells while testing.  I had soldered wires at the end of paper pins with shrink sleeves for this purpose out of necessity when I started initially, but got a cell checker as soon as I came across them.

Here is the balance connector tap I built for safely checking voltages out of individual lipo cells.

if you are dismantling a Lipo, be ready with a fire extinguisher... ;D
jokes apart... but it is seriously very risky and not recommended for non-experts. A short circuit for a fraction of second can lead to fire... so be extra careful... :-\

with all the comments and recommendations  from the experienced forum members ,i checked the voltage of each cell using the watt meter and found the voltage of each cell to be around (3.89,3.91,3.39) respectively.and there is no bloating at all just the bends only.so now i think i can use the same one .but what precautionary measures i should take off during the charging and shud i keep on checking the voltage and temperature all the time when i do charge them.any ways thanks to all the forum members for giving their kind comments as i was very scared of these.should i use some kind of duct tape to safe guard it or not. :) :) 
 

I would suggest that you watch it for the first 15 minutes or so at least when you charge, watching out for any puffing, and touch it periodically to see if it is getting unduly hot.

Also, just to be safe, do it on a non-flammable surface like the plain floor (avoid wood/carpets etc).