Supercard DStwo: a truly battery drain?

The 3DS is a new one and I just bought it last month, however, when  I played with the Supercard Dstwo card, the battery went from 4 bars to 2 in about 1 hr and 45 mins of a gameplay.

Brightness I set is 3 and surely it's not too high, however, it does seem kind of short. Is the dstwo really that bad at battery drain?

The reason is that the Supercard Dstwo has a SoC (System On a Chip), and It has its own CPU, RAM, etc. That's one reason why it drains the battery so quickly.

Another problem with the DSTwo is that when you enter sleepmode on the 3DS.  It seems that DSTwo can't tell when the 3DS enter sleepmode and keeps working like if the 3DS where in use, so when I use my DSTwo on my 3DS, I have a Nyko powerpack+ installed and the battery last more than that, I always use the brightness at level 1 with energy save off and wifi always on.
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