It's those lithium batteries - happens to laptops and cell phones too. Generally, non lithium batteries don't do that. Lithium is so cheap they drive the industry despite random fires since the 1990's. Somebody somewhere is paid to look the other way, because this should never have been approved. It's not like they didn't know at the time this decision was made. They knew. Everybody knew. It's like how America pretends Biden is the president. They are lying, and we know they are lying, and they know that we know they are lying, and they are still lying.