If turned on with no consumer attached on the battery it switches itself of after a minute or so.
If you know something about electrics and soldering then a light bulb of a car gives a solution as i use it.
Light bulbs for cars come in different wattage or even a 12v halogen spot will do.
A phantom in the air draws about 20 to 26 amps.
I have made a plug that fits the dji battery socked and soldered 2x 21w 12v bulbs to it.
It draws about 3.5 amps.
P = U x I as I = P/U so current drawn by 42w = 42 devided by 12 ( for a full battery and yes i know its 12,6v, i use 12v as its approx the middle between 12,6 and 11,4 for a half charged one ).
So when using 42w or a halogen spot of 50w it takes approx 20 min to draw 2,5amps or just till it shows half full on the display leds of the battery.
After that put the battery in the fridge.