Today I was updating the batteries with the latest firmware that just came out and when I got to a TB47 (4500mAh) battery, it didn't respond at all. I've used it under 10 times. The last time it showed normal behavior was when I was charging it yesterday. To my knowledge, the led lights went out as they do when fully charged but don't know for a fact if that's why they went out. No visible bulging or deformity of any kind. Anyone else experience a new battery gone dead like this?

I have had 2 die on me now while trying to update their firmware.  I am very stumped.

Maybe you should try to reset your battery:

http://forum.dji.com/thread-16060-1-1.html

Yeh, I have the same problem. I discharged the battery fully on my last flight - 1 week later which is today, I connect the charger and nothing happens. The purpose was to update the firmware. Isn't that strange! I also used it around 10 flights. The question is, is the battery under guarantee?

Good question.

phdraw Posted at 2015-5-28 04:24
Good question.

DJI released a new firmware today which sounds like it fixes the problem you're having.

Unfortunately, the battery has died before I could update it but DJI was quick to give an RMA# to resolve the issue.

Same problem here,
I bought two new batteries for an holiday trip, I used then 5 times each. And when I took them out from the case to update the firmware those 2 new batts are like dead. The 2 old ones have been updated with no problem.
So I tried this trick, disconnecting the balancer cable for a couple of hours. Now one is lighting up but all leds remain on for ever and I can not charge it at all. And the other one is still completely dark and not charging.
I will try to put the one lighting up back in the I1 to see what the soft tells me.

Thank you for any imputs about that matter.

Happy landings.

I'm not brave enough to mess with the wires. I got an RMA# and sent the TB47 in. They'll most likely replace it.