Late 2008 mbp battery issues

Hello forum members, I'm hoping I can find some advise for my dilemma. My late 2008 unibody 15 inch gives the appearance that all is well for the battery, cycle count is 80, status is normal and indicates 4100 mah capacity still. But when taken off power it's a different story. It doesn't just automatically shut down, if all I'm doing is word processing or light Internet use it will last 3 hours or so. It will then recharge when plugged in just like you would expect. But if I watch a YouTube video or something like that, it just powers off completely after a minute or two as if I pulled the plug. At this point I have to plug the MagSafe to get it to power on, and the battery will resume charging with a minimal percent gone. I ordered a non apple battery from amazon to see if a replacement could fix the problem but the Mac will detect it but not charge it.

I took the machine to a local apple specialist and their test indicated there was nothing wrong with the original battery and they would have to charge a minimum fee to diagnose. I'll take it if I have to but wanted to ask around first as I couldn't find a clear answer on the web. Thanks for any feedback

 

4 years old? batteries will break down and go bad from not being used correctly... this also includes NOT being used at all. It is likely a battery from 2008 is bad, its the models before Apple changed over to the new type they say will last for 5 years like they use now.

 

Sounds more like an overheating problem if it shuts down when doing something intensive. Have you removed the bottom panel and cleaned the heat sinks and fans of any dust/debris?


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Thanks for the replies. Saturn I thought the same thing too after i got home from the apple specialist and pulled the bottom panel and cleaned the fans and heat sinks. I even switched over to the "better battery life" setting to use the 9400m vs the 9600 gt.

And Doh123, that's why I purchased the replacement battery from amazon. Any idea though why it would recognize it but not charge it or be able to use that as a power source? I'm guessing it could be bad too even though it's supposed to be new, but I have no other macbook to test it in.

 

it could be the charging/power circuit on the motherboard is messed up. sadly its not exactly an easy fix. I would hit up an Apple store. I had similar with an 09 17"

 

KCE, Just taking an initial look at logic board prices, this sounds like a $$$ repair especially if I'm out of warranty =(

 

you got it. Parts are NOT cheap

 

sometimes 3rd party batteries are just bad, or don't last long. After ordering 2 quite a long time ago, and having nothing but problems, I only get the real things from the manufacturer these days.... at least when it comes to batteries.

Battery diags being wrong is actually pretty common, but Apple techs are told to go by them anyways.

 

what happens if you watch the same youtube video while plugged in?

 

The system works without issue when plugged in. The only time it behaves that way is when it is on the battery.