Aaro Koskinen@ikkeT Even a genuine battery is a potential hazard. I wouldn't gamble because of 50 euros. Maybe if you want to save such amount, then run without a battery altogether (like I do on my 2008 MacBook).
@ikkeT Internal lithium batteries are anti-pattern: a) they lack proper hard case (which is primary reason for making them - to save BOM money in manufacturing). Hard case in lithium batteries would help battery to stay fit and make it more safe.
b) there's no way for end user to observe a dangerous swollen battery until it's too late. I once had ThinkPad where the battery got swollen so that touchpad stopped working.
I boycott such computers; with phones it's more difficult.