battery was suddenly down to 7%

[Sossity]

I have been running my mac on the AC cord today, I had been doing some photoshop stuff on it, then I shut down photoshop.

I left the room for about 1/2 to an hour, I come back & sit at my computer & see the charger light is orange for charging, notice my battery was at 7%. I did not unplug from the AC today, & the magnetic end of the cord had not come out, the last time I looked it was at 100% charge, at least the last time I remember for yesterday. I usually run off battery to about 90-70% to keep the electrons moving per instructions for notebook batteries from apple. But I had not unplugged & run off battery today.

 

[snaky69]

Sometimes the magsafe doesn't provide enough power for the laptop when really going processor hungry on it.

When that happens, the battery kicks in for extra juice, maybe that started happening without you noticing?

 

[ddehr026]

Maybe try resetting the pram?

 

[GGJstudios]

Maybe try resetting the pram?

PRAM/NVRAM has nothing to do with battery/power/charging issues. Resetting it will not help. Only resetting the SMC addresses such issues.

What snaky69 said is accurate. It's possible to drain power from the battery even on AC power. It's also possible that your battery isn't calibrated properly, so your readings are inaccurate. This should answer most, if not all, of your battery questions:

Apple Notebook Battery FAQ​

 

[Sossity]

Thanks for the link, it looks like I need to run a calibration, but didn't the computer sort of do this on it's when it ran down to 7%? or should I do a calibration anyway?

I also have my mac on in the energy savings area to never sleep,should I change it to go to sleep after a period of time? what time span should I specify in the energy settings for sleep for a calibration?

 

[GGJstudios]

Thanks for the link, it looks like I need to run a calibration, but didn't the computer sort of do this on it's when it ran down to 7%? or should I do a calibration anyway?

Yes, you should calibrate it, to make sure your readings are accurate.

 

[Sossity]

what sleep settings should I have? does it matter if it is set to not sleep? if I set it to sleep, what time frame should use for sleep in the enrgy savings settings?

 

[GGJstudios]

what sleep settings should I have? does it matter if it is set to not sleep? if I set it to sleep, what time frame should use for sleep in the enrgy savings settings?

It doesn't matter what sleep settings you use normally. If you're calibrating, however, draining the battery goes much faster if your Mac doesn't sleep. To prevent that, use the Caffeine app (link in the Battery FAQ under CALIBRATION.)