Laptop as a desktop

tim wrote in post #16266400
If you're using it exclusively as a desktop then taking the battery out might not be a bad idea. Sure LiIon are good, but they'll last longer not used than constantly being used a tiny bit - I assume. Though you lose things like backup power if someone kicks a cord.

The biggest issue isn't that they are being used when inside the laptop. The biggest issue is that they are way warmer inside the running laptop, and the temperature of the battery greatly affects how fast they age. It makes a huge difference to have the battery at 40-50C inside the laptop or at 20C on a table - or at 10C in the fridge.

The bad thing with Li-Ion is that they age just with time even when not used. This slows down at lower temperatures.

BrickR wrote in post #16268226
My Sony laptop has a setting that will only charge the battery to 80% when plugged in and after that will run on AC power only while plugged in. I like it. Wish my Toshiba did that.

That is very good. Li-Ion batteries should not be fully filled for long-term storage - they age faster when fully charged.

Unless the charger or battery is faulty, then continuous use connected to mains shouldn't be dangerous. And even if the charger is faulty, the battery supervisor chip inside the battery is expected to disconnect the battery cells if the current or temperature gets too high. So fires normally comes from either having production issues with the battery cells, or having a battery supervision chip that is incorrectly configured - i.e. to believe that the batteries are able to handle much higher currents.

Over the years, all major battery manufacturers have had to suffer recalls because of production issues. But today we see very few recalls compared to 10 years ago - the battery supervisor chips always in use today are doing a great job of permanently shutting down problematic batteries. And the factories are much better at calibrating and pairing cells when producing multi-cell batteries (i.e. batteries with more than 3.6V), to avoid one cell being significantly weaker.