Is 15% battery too much to loose overnight?

[vistadude]

I just wanted to update those interested. My macbook was regularly losing 15% battery overnight in sleep mode. To make sure it wasn't the battery going bad, I did a complete shutdown and overnight I am losing 1% battery. Overnight means about 10-15 hours without being charged.

I ran the terminal program and nothing is waking up my macbook during sleep. So it seems this is most likely due to powering RAM during standby. I have 2 sticks of 4 GB ram for a total of 8 GB RAM.

 

[Blue Sun]

I just wanted to update those interested. My macbook was regularly losing 15% battery overnight in sleep mode. To make sure it wasn't the battery going bad, I did a complete shutdown and overnight I am losing 1% battery. Overnight means about 10-15 hours without being charged.

I ran the terminal program and nothing is waking up my macbook during sleep. So it seems this is most likely due to powering RAM during standby. I have 2 sticks of 4 GB ram for a total of 8 GB RAM.

Type "pmset -g" into the Terminal.

What does it say next to "hibernatemode"? A 1 or a 0?

If hibernate mode is switched off (0), then the computer does not write the contents of the RAM to the hard drive prior to sleep (handy for SSD's) and therefore must continually keep the RAM powered - resulting in significant battery drain during sleep.

 

[Silmarien]

Before 10.8.2 I used to lose about 10% overnight or less. Now with 10.8.2 even though I have less battery life I lose about 4% overnight.

 

[vistadude]

It says "command not found"

Type "pmset -g" into the Terminal.

What does it say next to "hibernatemode"? A 1 or a 0?

If hibernate mode is switched off (0), then the computer does not write the contents of the RAM to the hard drive prior to sleep (handy for SSD's) and therefore must continually keep the RAM powered - resulting in significant battery drain during sleep.

 

[bill-p]

It seems like a lot to me. My rMBP can be put to sleep for the whole night and not lose 1%...

I can confirm this as well. The rMBP doesn't lose even 1% over a 12-hour standby.

But I think it's because of the new hybrid-sleep feature where the rMBP saves its state to the fast SSD and then turn off completely or go into an even lower power state. When you open the lid again, information is read from the SSD back into RAM.

I always liked having that on my MBA, and thankfully, since the rMBP has SSD as standard, it does this.

Prior to this, my 2011 MBP 15" would always lose about 5% - 10% overnight.

 

[Blue Sun]

It says "command not found"

Try "sudo pmset -g".

 

[vistadude]

What does this do? It asks for password, I'm guessing it changes something permanently?

Try "sudo pmset -g".

 

[Blue Sun]

What does this do? It asks for password, I'm guessing it changes something permanently?

The sudo command allows admins to execute commands as a different user. Enter your password when prompted, I guarantee this will not harm anything.

EDIT: It does not change anything, it merely displays your current power management settings.

 

[vistadude]

Here's what it says with that command.

Active Profiles:
Battery Power -1
AC Power -1*
Currently in use:
hibernatemode 3
halfdim 1
lidwake 1
acwake 0
womp 1
sleep 0
disksleep 10
sms 1
hibernatefile /var/vm/sleepimage
ttyskeepawake 1
displaysleep 10