It is normal for it to perform a full discharge of the battery as part of its learning cycle every 90 days. Make sure it is not that. If not that as the reason, give it 24 hours. If it is fully charged, update the system firmware (including RAID firmware, driver first). If not fully charged still or it reoccurs soon, then replace the battery - power down to replace.
Hi,  I got an Yellow warning about  DELL T420 "Battery on Controller PERC H710 Adapter" What does it mean ?  What do I need to do ?  Order new battery ?  It`s a simple replacement mission? Does it critical ?     Update: testing url  [URL]  Didn`t do nothing , Everything looks fine now.....     Thanks   
DELL T420 - Battery on Controller PERC H710 Adapter