I have been pretty happy with Diablo especially after the update, because I have gotten really really good battery life. But recently I started using a 4GB ADATA SDHC card, class 6, and my battery life seemed to be hit.

I did a series of tests using the battery-status program and several SD cards. The other cards I have are 2 Sandisk 1GB, 2 Sandisk 2GB, 2 Patriot 8GB, 1 PNY 512MB, 1 Nokia 256MB. I tested my n800 with no cards first and the battery drain on idle was .4% per half hour, when testing all the other cards in the same manner, they all came in at .4% per half hour as well, so no additional battery drain. But the Adata card comes in at 1.6% per half hour of idle, or four times the amount of battery drain over the other cards. This is even after reformatting it, once as fat32, once as ext2, no change. The card functions fine in every other way and I get no errors on running checks.

Does anyone else have Adata cards? they might want to compare their battery drain on idle to the NIT with no cards using the battery-status app.

I have an A-data card. What is your method for figuring the rate per 1/2 hour. I will give it a test.

Good info,
so we know that the Patriot 8gb micro's are flaky and the 4GB ADATA SDHC card suck power.

Look at Bugtrack https://bugs.maemo.org/show_bug.cgi?id=1204#c75 (comment 75 from Nokiaman)
And I'm look in to Transcend SDHC card specs:
500 mA!! Splendidly!
Thus, not every card is intended for a IT...

Thanks bluesubaru

First you need to install the battery-status application

here's the download link
http://nitapps.com/dists/chinook/use....0-2.armel.deb

After this is installed you can open up the terminal application and type

battery-status -d 30

and then press the enter key.

This will create an entry in the terminal screen with the time and percentage left every half hour, I let mine run for two hours, to make sure it was consistent.

First I did this with no cards in either the internal or external SD slots, and I also was not using Virtual Memory either. This was to establish a baseline. Then I ran the test with each of my different cards in the external slot. I also did a test with each in the internal, but you probably don't need to do the internal slot test, I was just seeing if there was any difference, and there wasn't.

What's flaky about the Patriot 8GB?

Thanks for that info. Adata doesn't seem to have power specs on it's cards, but they do say it supports SDA 2.0 and all power modes, which should include standby and sleep. The tests I'm running are with the NIT essentially idle, so the cards should be in either standby or sleep mode which I thought was supposed to be power in the microamps range, not even milliamps, so there should be no discernible power loss. My guess is that maybe the adata cards aren't entering this mode for some reason?

Just throwing my 2 cents in, I had two A-data 8GB SDHC cards and they both went from flaky to dying. My opinion is that I would avoid them, given my experience.

My A-Data 8GB SDHC is still working well after 6 months. Sounds like I need to keep an eye on it.

I have 4GB AData sdhc micro.
Didn't notice any visible performance drop, I'll give this battery monitor a try.
Cards like any other memories - there are better and worse.
Unfortunately It's not possible to draw any conclusion if there are differences like - this has lower X-current, but that does this X-thing faster and so on.