I had an old Samsung cell phone about 5 years ago where if you set an alarm and the phone is off when the alarm is supposed to go off, the phone would turn itself on to sound the alarm. If my battery ran low, the phone powered itself off but it would still wake itself up to sound the alarm as long as the battery wasn't completely dead.
I set an alarm on my Nexus S and then turned off the phone and it did not wake up when the alarm was supposed to go off. Is there a way to make the phone wake you up if you have an alarm set while it is off?
Has anyone ever had their Android crash in the middle of the night and ended up waking up late because the alarm didn't go off? I just got my Nexus S and don't know how reliable it is yet.
There is a fix for that for the samsung captivate because it randomly shuts its self off, i imagine that this fix can be replicated on the Nexus S....if you want me to investigate this further and how it would work well with a Nexus let me know
Instead of turning the phone off, you could just put it into Airplane mode. This way your alarm would still go off and you wouldn't get interupted by incoming calls/messages/emails etc and it would also save your battery quite substantially.
You can add a widget or shortcut to the desktop for quick access, or simply hold the lock button for a few seconds and select it on the menu.
As for reliability, I use my Nexus S (and before that Nexus One, and HTC Magic) to wake me up every day and I haven't had issue.... yet :P
That is a feature I actually love on my BB.. I can leave it unplugged, 'shut it down' without it going into full power down kinda like a PC in 'sleep mode' and it will turn back on and ring on time, every single time and with FULL battery still... I wish android phones were cabable of such as well.
Like mentioned above, instead of turning it off just use airplane mode. My N1 uses near zero battery in airplane mode. That way your battery doesn't drain but it will still run the alarm and anything else besides voice and data. One caveat is if some services keep trying to connect anyway, not sure if that happens or not.
Interesting note. I have a GSII and it sucks that it does not have a function like that.
But my GF had a HTC Wildfire and it had that function you could turn it off at night and the alarm still went off.
I am now looking through the web searching for a new phone that would have this future and new hardware.