The Remote Control used by the Agras T50 remote has an internal battery. For long days, a WB37 battery can be inserted into the remote control to lengthen the use time of the remote. 

Every agricultural drone pilot should have a few WB37 batteries. You never want to be in the position where you're grounded while you wait for your remote controller to re-charge.  

NOTE: We always sell and recommend the 100W charger with this, to allow for faster charging. 

Technical Notes: 
This 2S 4920mAh battery has excellent discharge performance at low temperatures and charges quickly.