Concerns in testing a potentially water damaged Macbook battery So, I acquired a water damaged Macbook (Late-2008 Unibody / 5.1) to cannibalize for parts for my existing macbook of the same model.  I've taken everything I need off it, so I'm looking to part out the rest of the components to recover a few dollars from what I paid for it.  The logic board is pretty obviously fried - absolutely no life in it if I attempt to power it on.

However, the PMC seems to be intact.  When I connect a charger it lights up green, then orange like it's charging the battery.  The charge indicator lights on the side also come on and indicate a discharged battery (one blinking green light).  

So, given that the battery may have been water damaged, but shows no symptoms of it, how should I go about testing it, and what should my concerns be?  If it seems to be holding a charge in the damaged macbook, could it still damage my fully-functioning macbook if I plugged it in to test it/check the capacity?
If you have the Apple Service Toolkit, that is the easiest way, if you don't... there aren't may programs out there really suited for this type of work. 

If you are showing that the battery may be holding or attempting to obtain a charge, the battery probably will be OK to be used. I am sure that enough time has passed in where the battery has been completely dry.  In many cases you could submerge the battery, dry it off and it will work. The batteries are pretty much air tight to begin with. 

If a battery had a crack in it, or something of the sort you'd know.  

The best thing to do is to attempt to get a charge out of it, if the battery holds one you are fine, if not then you may be able to go down to an Apple Store and ask if there is a way to view how much life is left in the battery.

Of course, this is assuming the battery hasn't been saturated in salt water either, if it has, you may just want to throw it away.  Otherwise I think you will be safe to use it as long as it holds a charge that is.