Possible power drain in Tails 4.12 upwards
I think there might be something causing unnecessary power drain since Tails 4.12. My experience is that the battery life of my laptop is hugely reduced since then. I've also noticed that Unsafe Browser and Thunderbird are both taking much longer to launch since 4.12, which may be related.
The battery life of my laptop has reduced by at least 50% since 4.12. Such a sudden change isn't going to be because of a sudden drop in battery capacity, I think. It's so bad that once I got the 'extremely low battery, laptop will shutdown very soon!' notification and in the 5-10 seconds it took me to find my charger and plug it in, the laptop battery died and the laptop shut down! This has never happened before, normally I get at least a couple of minutes.
I've also noticed that the remaining battery time in the Power menu is only about an hour when the battery is 100%, but before 4.12 this was usually at least 4 hours.
I've tested this with a backup copy of Tails on a different USB thumb drive and the result was the same, so battery drain and much slower launch times for Unsafe Browser and Thunderbird.
I can provide logs for troubleshooting if you tell me what to do.
Edit: Should point out that I haven't made any other changes to my laptop or the USB thumb drives I use, upgrading Tails is the only difference.