|There's your problem, it's a virus!|
Charlie Miller's managed yet again to render several Macbooks, Macbook Pros and Airs useless after gaining total access to their battery's micro-controllers' firmware via a security hole. Evidently, the Li-ion packs for the line of laptops are accessible with passwords he dug up from an 2009 software update. He mentions that someone could "use them to do something really bad," including faulting charge-levels and thermal read-outs to possibly even making them explode. He also thinks hard-to-spot malware could be installed directly within the battery, repeatedly infecting a computer unless removed.
“You could put a whole hard drive in, reinstall the software, flash the BIOS, and every time it would reattack and screw you over. There would be no way to eradicate or detect it other than removing the battery.”