By the time it happens, it is generally too late to shut off the charging circuit -- it helps and it happens but the battery destruction is already underway. The question next is whether it will catch fire or simply 'swell up'. At this point it's mostly up to luck, the available fire-prevention mechanisms are stronger battery enclosures, which would be heavy, bulky and expensive -- exactly the things most consumers do not want and would vote against with their money, reducing the profits of the company innovating in this direction.
Another way to prevent fires would be attempting to detect dendrite growth by the changes in observable battery state (capacity, amperage, etc). This is hard, expensive and will likely give a lot of false alarms requiring warranty replacement, once again hitting the would-be innovator in their pockets.
That is why I run my "vintage" MacBook pro without a battery (first unibody, with swappable battery), always plugged in. It works for me as it stays stationary at home. If I need to unplug for any reason, I close the lid and macOS saves everything, then unplug, replug later, and nothing is lost.
Wow, I love that. Still, there must be some small coin-sized battery on the motherboard that's saving state, which will have to be replaced at some point?
Problematic if you have a magsafe connector in combination with kids or pets running around though. Or just if you trip over the cable yourself. In my unfortunate experience :P
Second time my 2012 13" MBP battery swelled up. Glad on the older model you can at least replace parts yourself.
I think my problem might be that I treat my laptops more like desktops and keep them plugged in 24/7 and hardly ever run them off batteries. Last battery only had 2 cycles on it.
I want to get into vlogging at some point, so might at some point upgrade to a 15 inch with a GPU. I love Apple's software but disappointed the newer hardware isn't user serviceable anymore.
By the time it happens, it is generally too late to shut off the charging circuit -- it helps and it happens but the battery destruction is already underway. The question next is whether it will catch fire or simply 'swell up'. At this point it's mostly up to luck, the available fire-prevention mechanisms are stronger battery enclosures, which would be heavy, bulky and expensive -- exactly the things most consumers do not want and would vote against with their money, reducing the profits of the company innovating in this direction.
Another way to prevent fires would be attempting to detect dendrite growth by the changes in observable battery state (capacity, amperage, etc). This is hard, expensive and will likely give a lot of false alarms requiring warranty replacement, once again hitting the would-be innovator in their pockets.