ahhh, my bad. 
a laptop.
don't know if a laptop motherboard would have a battery, don't know why it wouldn't. regular desktop motherboards have batteries. they look like a small nickle. it's nesteled in the motherboard.

i'm not encouraging you to open your rig up if you aren't comfortable with that. but with desktop's it is fairly obvious once you know what to look for.

how old is your sled? batterys should last 1-2 years but anything is possible. some say to replace it yearly. i've had mine go wonky before and replaced it. 
if you do go in there you need to make sure that the laptop is unplugged from outlet and that you are constantly grounding yourself (skin) to the metal case so as to not induce a static charge. static electricity is a killer for this stuff. not rocket science but just be aware. if you have a static charge built up within yourself (shuffeling your feet on carpet) then to discharge you need to touch some metal somewhere, and then go from there. also, no magnetic tools...harddrive failure.

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