I have a bunch of cards and wanted to know which card that drains the battery most and with what application , using a multimeter connected to the battery i was able to get maybe not perfect but very comparable measurements. Most of the tests is done with the settings i normally use , First test is to see the consoles just being left in their menu without cards. Brightness 2 on Lite and 4 on XL is what my eyes like most , so im using them in the tests. Next is to see what happens with Gamecard and Flashcards in Slot1 , still in the menu. Gamecard eats nearly nothing and CycloDS is also very good , other cards did worse and DSTwo burns alot just doing nothing and also in standby. This is what happen when playing a game and in the flashcards menues , also what happens in standby , sound off & after soft-reset in WiFi. The ingamemenu with DSTwo is hard on the battery even with the lid is shut , soft-resetting with wifi going on is also a powertrap .Sound on or off is just a few mA. And so a GBA game. Not much to say , level up processorpower don´t do that much . Multimedia then. Wow , DSTwo does it better than AK2i . Comparing a few MicroSDcards. Not sure if im any wiser after this ? More tests needed . And last some different tests with wifi , 3in1 and DSI-programs. DSI programs seems to cut out slot1 , saving power ! Conclusion for this test : * Flashcard consumes a lot of power even in standby when lid is shut *Softreset in wifi-mode makes it a power trap *Some flashcards consumes a lot of power just being inserted *WiFi uses a lot too. *Micro SD cards maybe differs ~10mA in some cases , not so much , more tests needed. *Speakers uses very little power. *DSI XL , big screens takes a lot of power *BatteryLife in DS-Lite is 1000mAh & 1050mAh on DSI-XL , that means 10 hours of gaming with DS-Lite if the current is 100mA and the battery really containes that much . *Im very pleased with my CycloDS card , works well and is easy on the battery , my favorite! Left to test is cheat , real time guides and homebrewstuff etc. , maybe some other time. Thats all !