Swollen apple

My wife's MacBook Pro is almost 3 years old.  She noticed that the laptop no longer was level on the table and mentioned it to me.  Upon turning it over I found that the battery was not seated right, I removed it and noticed that the damn thing was pregnant.  I looked around for some amorous energizers or litium-ion batteries but found none.  For the last month we both noticed that the battery would heat up more than normal and not shut down with a warning, it would die so we knew the battery was in need of replacement.   The swelling battery is more of a concern so I put it in a corner and waiting for the expectant mother to pass whatever is crammed up in it.  Searching online I find it is a common issue and one that Apple refuses to recall or address.  We seem to have gotten a lot more life out of the $160 battery than others who see just over a year of use before the immaculate conception takes place which for some magical reason is just past the warranty is over.  I was not surprised.  I am looking to get some sort of chastity belt for our current virgin battery that may curb any divine dry humping.