Haven't flown in almost two months, went to charge up all my batteries and take my p3 out with all great fall folliage. One of my batteries wouldn't light up and charge and then I noticed it was swollen. I disconected it and put it aside. The rest of the batties are all fine. I have 4 batteries, two I got from DJI when I bought my P3 and two I bought after the fact. DJI customer service page says to contact the seller first but I am not sure which seller sold me the battery. DJI or American dealer. I looked at my invoice online and it doesn't list serial numbers. Any idea where to look for serial numbers from the seller, do they keep the serial numbers? Also what could have gone wrong to cause the battery to swell. Could I have caused the damage with incorrect charging and discharg procedures. Any help would be appreciated.
Ed

Seems like there are stickers on the bottom of the battery that are unique......looks like serial numbers to me.  I have to assume that DJI would have a record of the serial numbers of the batteries that they sell directly......I would call them to find out.

Under the NOTICE section of the Battery Saftey Guidlines that comes with the battery and in the user manual, there is a section that is titled "Battery Maintenance" .  Under that:
#2   Battery life may be reduced if not used for a long time.

What a "long time" means, your guess is as good as mine!?
This probably will give you little help but maybe someone knows a more specific answer.
The one thing I do know is that a swollen LiPo battery is bad.......be careful with that thing!!!

Take it to your dealer and "act as it is raining" is my best advice

Lipos often puff when overly discharged. I have over a hundred Lipos and I usually retire them once they puff. I certainly would not fly anything expensive with a puffed Lipo.

There is lots of information on the WEB about Lipos and care for them. DJI has simplified charging and balancing as well as storage.

Most Lipos are dumb and you have to do the balancing and storage yourself. There is even a recommended breaking procedure, and that is to only fly gently, no full throttle for the first 10 flights or so and don't discharge below 50% during the breaking period. This will help Lipos live longer and store full or close to full charge longer.

Another key trick to long life with Lipos is never discharge below 30%, I always land at 30%, my absolute limit is 20% any less then that and you may puff the Lipo and the life span will shorten. Personally I don't understand the 8% discharge DJI talks about. Maybe someone from DJI can comment here.

I typically get 500 cycles or more from my Lipos before retiring. Once they don't charge up above 85% or so I retire them. I always store lipos between 35% and 70%, never fully charged. Charge within 12 hrs of flying. If not used then fly them down to 50% to store, even just hovering in your garage if it is raining.

I doubt DJI lipos are different from most Lipos, so I use these procedures on my phantom Lipos.

Here is a good link to Lipo info:
Lipo info