"J. P. Gilliver (John)" wrote:
[...]
Thank you. I find I already have "Critical battery action" set to
Hibernate (which I think is the default). I have changed "Critical
battery level" "On battery" from 2% to 3% - I'll see if that makes any
difference. I only have about 3G of RAM, so it shouldn't need long to
hibernate.

As Ralph also mentioned, 2 or 3% is very low and most likely too low.

FYI, my HP laptop is set to 9% and that is the (installation) default
setting.