You're fearmongering all over this thread. Stop digging, you are at hobbyist level with your knowledge on a forum with professionals. if you can't tell the difference between 'batteries will swell some during their operating life' vs 'excessive swelling is a sign things are about to go pear shaped' then you shouldn't be working on your own laptop period.
Any laptop older than 12 months will have a slightly swollen battery (even if that swelling is accommodated by the case immediately around the battery so you won't see it).
HN stands for 'hacker news', if batteries scare you then don't use them. The same goes for powertools, explosives, household cleaning products, chisels, hammers and so on. Danger is a relative thing. Knowing the head fire marshall of a very large (2 million inhabitants) European city: if you are afraid of fire then you should disconnect all your wall-warts. Those are the cause of a very large number of fires and the best way to deal with them is to switch them all off when you leave your home. Batteries are a very distant second to that and stories of them catching fire are rare enough that they make the news. See also: Samsung and Boeing.
Note that a perfectly good battery can go into thermal runaway in a couple of seconds if mistreated, the amount of energy these pack is very impressive and if that energy is released quickly then the results can be catastrophic, even resulting in the hull-loss of airliners if the combination of circumstances is particularly bad:
Did you even read the text of that link? In case you didn't:
"Apple carries out a number of iPhone repairs in-store these days, but there is one fault that stores are forbidden from touching, and that’s swollen batteries.
There’s just too high a risk that these will be accidentally punctured during disassembly or removal, and a video of a DIY attempt at replacing a swollen battery in an iPhone 5s provides a graphic illustration of this…
Reddit user tryagainin47seconds posted a video of a coworker attempting to dismantle an iPhone, which burst into flames. The most likely explanation is that the man punctured the battery.
The battery itself appears to have been third-party[+].
Battery had been replaced by coworker who originally owned the phone and he thinks it was faulty equipment. Battery was swelling up when I charged it and he was taking it apart to see what was going on."
[+] -> this is a pretty important detail and my indicate a battery that was not matched well to the charge circuitry leading to an accelerated degradation and/or outright destruction of the cells.
Which pretty much confirms just about everything I wrote above modulo some edge cases that this particular instance did not cover.
Batteries that have swollen outside their design parameters are a lot more risky than those that have not, and that clearly was the issue here.
And it does not say anywhere in that article that 'swollen batteries are not to be used', though - again - you'd be pretty dumb to use batteries that have a pillow shape indicating significant gas development has occurred which most likely has all kinds of negative effects on the state of the laminations and the batteries' ability to keep a charge. But a battery that has expanded a bit can be perfectly safe to operate assuming it is still within design parameters.
Anyway, I'm done with your name calling, have a really nice day and enjoy your safe life without any Lithium tech. Because swell they will, whether you like it or not.
Some more interesting links for people interested in battery tech:
Any laptop older than 12 months will have a slightly swollen battery (even if that swelling is accommodated by the case immediately around the battery so you won't see it).
HN stands for 'hacker news', if batteries scare you then don't use them. The same goes for powertools, explosives, household cleaning products, chisels, hammers and so on. Danger is a relative thing. Knowing the head fire marshall of a very large (2 million inhabitants) European city: if you are afraid of fire then you should disconnect all your wall-warts. Those are the cause of a very large number of fires and the best way to deal with them is to switch them all off when you leave your home. Batteries are a very distant second to that and stories of them catching fire are rare enough that they make the news. See also: Samsung and Boeing.
https://en.wikipedia.org/wiki/Samsung_Galaxy_Note_7#Battery_...
https://en.wikipedia.org/wiki/Boeing_787_Dreamliner_battery_...
Note that a perfectly good battery can go into thermal runaway in a couple of seconds if mistreated, the amount of energy these pack is very impressive and if that energy is released quickly then the results can be catastrophic, even resulting in the hull-loss of airliners if the combination of circumstances is particularly bad:
https://safetyfirst.airbus.com/lithium-batteries-safe-to-fly...