I have 5 pairs of TB50's which I fly my Inspire 2 with.
However, I've not flown in around a month. All my batteries were left at a safe storage charge after the last flight, but when I went to charge them yesterday, one of them wouldn't start charging. I tried turning the battery on but I can't even get a charge reading from it. I left it on charge overnight and the charger still hasn't even recognised it's plugged in.

Any suggestions or is it completely dead?

Which firmware version are you on?

Hi, we're sorry to know about the situation. I'm afraid that we couldn't provide further troubleshooting steps as the battery would not recognize the charger, however, if this battery is within the warranty then you may wish to contact our support for further action and options. Please see the link below if you wish to contact our support.

www.dji.com/support

JBSonic Posted at 1-29 02:35
Which firmware version are you on?

I can't check exactly what version as the battery doesn't boot but I last updated it after the update to fix the big voltage level issue.

Byte Posted at 1-29 09:33
I can't check exactly what version as the battery doesn't boot but I last updated it after the update to fix the big voltage level issue.

So to recap, V200 firmware version was first released by accident.. with bugs.
The firmware was recalled and then re-released.
The firmware addressed some issues with the batteries.
V300 (the latest one) has again re-introduced battery issues. A lot of people have mentioned that the latest firmware bricked their batteries, or made them suddenly drop to 0% mid-flight, or even show as "N/A"
One user posted here on the forums that he had 13 batteries in total destroyed that way and DJI did not offer to replace.
So if you have still battery warranty left, send them to DJI (the warranty period is 6months)

If you dont have warranty anymore, then I am afraid you will have to go and buy new batteries, despite there being no guarantee that the new batteries won't break too, BUT at least you then have the warranty and can send them back immediately.

Obviously this is a wierd situation and many are wondering what the hell DJI are doing. At the same time remember that DJI has been drowned in corruption problems with as many a 52 of their staff overcharging customer for parts and what not for their own personal gain. It has cost them, wait for it: over $150m in lost revenue due to internal corruption, blaming poor controls and internal processes.

So yea, make of that what you will, the battery situation is a complete disaster and DJI wont help you

JBSonic Posted at 1-31 05:17
So to recap, V200 firmware version was first released by accident.. with bugs.
The firmware was recalled and then re-released.
The firmware addressed some issues with the batteries.

Great insight into the situation, thanks very much for your advice.
DJI have sent me shipping details for the battery, but on the form when I filled out the issue it also explicitly said not to send in batteries so I'm a little confused.
If you don't mind me asking, what firmware are you running on your batteries?

I think I am on V100 still but I have not checked, haven't used the Inspire 2 for months, too many issues.
It got banned from commercial use here in the UK for a few months and could get permanently banned if there are more issues, which there seem to be. Look at the posts where people have their batteries brake/fail. Doozens of them, literally thousands of $ in broken batteries and DJI wont replace them, instead they tell them to buy more and hope they dont  break either.