Will Not Run On Battery Power, Only AC

I bought a MBP about 2 months ago and everything is great. The other day I noticed my MBP wouldn't work on battery power. So I plugged in the AC adapter and it works fine. Pull the mag plug out and it shuts off. I check battery power level and all the LEDs light up. When I push the power button I hear what I think is the HD starting to spin up, but then it just stops. I tired doing the system management controller (SMC) reset and that did nothing. I also did the Power Management Unit (PMU) reset and that did nothing too. The only thing I can think of is that day it started doing this, there was a power outage at my house while I was at work. But when I got home it was working just fine. It was a few hours later did it start doing this. Any suggestions?

hrm i had that problem on mine breifly.
i could run it on battery from 100% charge tho,
so i charged it up, took off AC, and cycled battery (ie. ran completely flat till MBP went to sleep then charged to 100% again), and it worked perfectly from then on.

tho work collegue has MBP too and his wont run at all on battery,
tried my battery in his MBP and it ran fine so hes waiting on new battey now.

hope some of that helps.

MacBook Pro not run on battery power - SOLVED

Solved, at least for me.

I was crestfallen when I read that purevil had experienced exactly the same problem as I - after a power outage while running on AC, my MacBook Pro would no longer run on battery.

The machine recognized that there was a battery installed (or not, if I removed it) and its level of charge (would charge fine when installed); it just wouldn't run on it.

Same deal - MacBook Pro would simply die if MagSafe unplugged from unit... zapping PRAM, restarts etc, wouldn't make a difference.

So, I took a cue from my recent experience getting Sony digital video camera to communicate over FireWire: I unplugged power, removed battery, and left the machine for a few hours.

Came back, reassembled, works fine for me.

Hope it does for you, too !


Hal

PUREVIL said:

I bought a MBP about 2 months ago and everything is great. The other day I noticed my MBP wouldn't work on battery power. So I plugged in the AC adapter and it works fine. Pull the mag plug out and it shuts off. I check battery power level and all the LEDs light up. When I push the power button I hear what I think is the HD starting to spin up, but then it just stops. I tired doing the system management controller (SMC) reset and that did nothing. I also did the Power Management Unit (PMU) reset and that did nothing too. The only thing I can think of is that day it started doing this, there was a power outage at my house while I was at work. But when I got home it was working just fine. It was a few hours later did it start doing this. Any suggestions?

Click to expand...

OK now its weird..... if I start my mac without the cable it works.... if I plug the cable in while its already started without it, it will run until I unplug it then it shuts off. If thats confusing here we go

MBP Off, Cable unplugged, turn power on, works fine.
MBP Off, Cable plugged in, turn power on, works fine.
MBP on, cable plugged in, remove cable, shuts off.
MBP on, cable unplugged, plug cabe in, then remove cable, shuts off.

Im going to drain the battery tonight, leave it out all day, then reinstall it and see what happens.

MagSafe anxiety

purevil, it seems your MBP has MagSafe anxiety.

You can do whatever you want when it's off, but don't mess with the AC supply when it's on . . .

: P

Seriously though... hope your idea solves it, but if not, try unplugging the power supply from the mains while leaving the magnetic end attached to your computer... that would indicate whether the problem is with receiving power per se, or something about the MagSafe conection.

Thankfully, mine seems ambipowerable, ie. operating normally.


Hal

hi, seems like i do have the same problem with yours. but my MBP will shut off instantly when using the batt for about 10 - 15 mins. The batt still have power in it (checked the batt indicator about 4 bars) and will run normally with the power adapter on.

could be your actual power adapter.... maybe something happened when the power surge happened

I solved it!!

Okay, so here's the scoop. I had the same issue with my unibody MBP and solved it!

Short answer: Traced problem to bad FW cable that was shorting out battery circuit. Made computer think no batt was connected even tho energy saver control panel said was there w/31% charge. Fix is to remove battery from the machine then put back in, or if like me you have a unibody model, open up the bottom & lift off the battery connector from the motherboard. Wait a min or two, reattach & you're back in business. See iFixit.com for access tips. You need size 00 phillips.

Detailed answer:
I kept thinking i had a battery issue. Laptop would die when power cord was removed. Restart produced message that date/time was way old, etc. -This made me think dead/bad pram battery, or worse: power supply board, or motherboard. But later found computer would also crash when I plugged in or sometimes removed my time machine ext drive cable. (I use a Belkin FW 800 to FW 400 cable as my MBP is 800 & TM drive is 400 speed). It would not crash when I used a regular FW800 cable to my drobo.

Took cable & plugged into my old G4 Powerbook, same thing happened. Dead, dead, dead unless power cord plugged in. However unlike the unibody it would keep running after a power cord restart & then while running, the power cord was removed.

Took 800-400 cable & connected another hard drive. Attached to PB G4 & same stake to the heart crash. So, problem traced to the cable.

Removed battery from PB G4, waited a bit & reinstalled it. Laptop started fine from battery.

Hoping the same thing would work on my unibody MBP, I opened the bottom case and lifted the connector of the battery from the logic board. You need a 00 Phillips screwdriver and (ideally two) plastic spudgers to lift the connector straight up. See Installing MacBook Pro 13" Unibody Mid 2009 Battery - Page 2 - iFixit.

This worked like a champ and I'm back in business.

@airmangirard

Do not cross post! You posted this same replay three times in different forums. Once in one forum is sufficient. Your other posts have been deleted.