Hello, I am running MacPro4,1 (Early 2009). First I got this RAID battery error (0x#0 = 18) 4 months after purchase and the battery was replaced by apple care (though I had to turn everything off and bring my card to the store for check, than do it again after 2 weeks when the battery was delivered so they can install it themselves, for some reason they didn't allow me to do it myself)... This time it happened again. It looks like I get this error when I leave my Mac Pro turned off for a few months (my business requires me to travel a lot and sometimes for a long time). When I come back my battery dies after a month or so by constant working MacPro (turned on 24/7)... I was thinking that it may be because I didn't turned off the battery when I left first time - this time before travel I turned it off. It didn't save it When I turn off Mac Pro and turn it on this error goes and it works fine for a few days... Just re-appears again. Well... Browsing other threads makes me think that this error is unsolvable and just a result of faulty apple design since a lot of other users having the same problem... I would be happy to get any solution but have not much hope about that. I might consider switching to 3-rd party adapter but since I already wasted so much money on original one - it's a pain Going again through the entire Apple Care procedure makes me nervous. So I am thinking about buying a new battery on eBay or somewhere else. The question is where (I am in Europe)? Are there any cheap OEM analogs? Seems that I have to change this ****** battery every time I travel for a few months. Thanks for all suggestions!