We have discussed the proper use and care of the DJI battery packs on numerous threads on the forum. I found this great little video with some common sense tips for taking care of your DJI Li Po battery packs.
Please check this out and feel free to comment below and add your experiences to this thread for all other Inspire 1 / Phantom owners.
Sounds like they have dropped below the safe voltage level or discharged below the threshold to accept a charge. (of course it could be dead too) I have some links for you to review and see if you can get your batteries going again.
report back what you find out for others to learn as well. If this is something you are not comfortable doing, then you may wish to discard the bad battery and purchasing a new one from DJI.
If your battery is bricked by the recent FW update AND you do not wish to pursue DJI support warranty OR you are outside the 3 months Battery Warranty Period, here’s a tip on resetting the battery’s IC FW.
Disclaimer: please only attempt to do this if you are confident and know exactly what you are doing. Be careful not to Short the red and black wires. Proceed at your own risk.
1. Carefully detach the battery’s top cover – a fine knife or flat head screw driver will allow you to easily unclip the cover.
2. Gently disconnect the balance plug / loom to the IC. Let it sits unplugged for 60min.
3. Reattach the plug / loom.
4. Fully charge your battery and do two full cycle at low level hover.
5. Condition your battery and you are good to go.
This will reset and fix all batt bricked by FW.
Enjoy and Safe flying