Rigol DL3021 - Battery test flaw?

[BellaminoBoy]

Hello,

i use my DL3021 only for battery and charger testing. Since the unit has no CP only CC in battery test i usually increase current as battery voltage goes down to make the test faster.

What i noticed is really strange. If the test is in progress, and you try to change current there is no over power protection. For example now im discharging a 60 V battery with 3 A, and i could easily increase current to achieve over 300 W and more. Is this a bug in the firmware that allows to set the unit over the maximall allowed 200 W rating?  I did try to discharge battery on 350 W for 15 seconds, and it worked, the display showed 350 W. I did not want to test longer, not to release magic smoke

Hope you understand me, not a native English speaker.

[BellaminoBoy]

I was asked by Rigol to provide a picture of this finding. I have also verified current with meter in series with the battery. In battery test mode the load does not care about total power. You can set 150 V 40A, 6000 W 

Here are pictures, 280-300 W at the moment. I have tried 500 W shortly, it proves the bug in firmware. I did not want to test much, dont want to destroy my instrument

[electr_peter]

Thanks for the info. I will try to confirm this on DL3000. Do you have latest FW on RIGOL? I guess temperature protection should kick in before it blows up, but that is potentialy serious issue.

Battery app on DL3000 has some bugs, one is mentioned here rigol-dl3021a-current-failing-to-load-consistently-in-battery-mode This bug has been reported to Rigol, hopefully they will update FW. Can you check this issue on your unit?

[electr_peter]

Constant power mode (CP) limits max available power to 200W as it should. In other modes, including battery app mode, power limit does not seem to be enforced correctly. OP mentioned 280W case in CC mode