Power Management issue

[ibl5588]

My macbook 13 inch, turns off when i unplug the power cord, i can use the battery when i boot it from the battery but it will randomly turn off anywhere from 10 minutes to an hour.

My boss at work used to work for apple so we knows that i either need to reinstall my operating system which i dont have or my computer is faulty which i hope not, i bought this macbook used it's 29 months old.

The battery says it's in "good" condition with about 211 cycles.

my boss said to check if there any new firmware updates which there aren't, he reset the PRAM and i also reset the PMU. This is really annoying. Do you think my battery may be dead just not registering that it is?

Model Name: MacBook
Model Identifier: MacBook2,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 1 GB
Bus Speed: 667 MHz
Boot ROM Version: MB21.00A5.B07
SMC Version (system): 1.17f0
Sudden Motion Sensor:
State: Enabled

He said my boot ROM looks really weird, that maybe the last owner tried to install some software that wasn't supposed to be on?

After i reset the PMU when i unplug the power cord it will work for a few hours and then go back to being all whacked out. So i think that my hardware is messed up or my firmware or the software or the battery is bad it doesn't make any sense maybe you can help thanks.

 

[djackmac]

Truthfully I think your battery is just bad or consumed. Seeing as the machine is 29 months old and batteries are a consumable that is only warrantied for a year I don't see Apple dong you any favors. You can try to recalibrate the battery by letting it charge to 100% then using it on battery until the battery depletes enough to go to sleep. Then charge the battery again to full capacity and keep it plugged in beyond that for another couple hours. After the calibration process is complete see if the depletion times get more consistent. Just to make sure its the battery, having another known good battery to use in your machine would also rule out any doubts you may have about the macbook itself.

After i reset the PMU when i unplug the power cord it will work for a few hours and then go back to being all whacked out. So i think that my hardware is messed up or my firmware or the software or the battery is bad it doesn't make any sense maybe you can help thanks.

On another note if you are constantly resetting the SMC to coax more battery life you may have just crashed your the SMC on the logic board which would also explain the irratic behavior. SMC resets are meant to be a last resort thing as opposed to being a quick fix whenever you are experiencing strange behavior.