View Full Version : Macbook 5,1 2008 Battery - 20 minutes

Nov 12, 2011, 10:34 AM
I gave this 2008 Macbook 5,1 to my son and he keeps forgetting his charger at school.
He has been charging it on his Mom's 2011 MacBook Pro mag safe charger each night - a 60W A1344.
Is there any big difference in the chargers? Have we damaged the battery? It seems to only hold a charge for 20 minutes vs about 4 hours before.
The battery has about 448 cycles.

Nov 12, 2011, 10:39 AM
It doesn't matter which MagSafe adapter you use. None will harm your MacBook. However, the battery is only guaranteed to retain up to 80% of it's capacity up to 300 cycles, and you're well beyond that. It may be that it's time for a new battery. Calibrate it and check your health with iStat Pro. This should answer most, if not all, of your battery questions:
Apple Notebook Battery FAQ (http://forums.macrumors.com/showpost.php?p=9875442&postcount=23)

Nov 12, 2011, 10:42 AM
It does not damage it. I would get a new battery though.

Nov 12, 2011, 11:02 AM
Thanks for the info guys. I will call the apple store today and get a new battery. A $139 battery is a good investment but I was afraid of killing the new one too.
I might also try calibrating it to make sure it's not a software or reporting glitch.

Nov 12, 2011, 12:05 PM
The original battery in my old uMB was showing 87% of original capacity after 850 cycles. Sounds like yours has a faulty cell in it.

Nov 13, 2011, 02:09 PM
Yesterday after writing that post, the battery capacity went to 3:50 hours. I didn't do anything to change it.
Worked like that all day - I surfed the net and did email on it for the entire time. I installed caffeine and let it run down, go to sleep, then plugged it in and charged over night. I fire it up this morning and it now shows 20:00,(hours?!), or 100% and says "replace now". I have been working on it for about 35 minutes on battery and no change in the number!
Bizarre to say the least.
Something odd is going on. I am considering unplugging and letting it run and see how long it will go tonight!
Any other tips or ideas?

Nov 13, 2011, 05:33 PM
It's worth calibrating the battery. Have a look in the FAQ that GGJStudios will have no doubt posted somewhere in here...