TLP 1.5.0
Features:

Battery Care

Sony laptops: stop threshold 50/80/100% aka "battery care limiter"
ThinkPads:
Use new sysfs attribute charge_behaviour for recalibration - in preparation for kernel patches not yet merged into the mainline kernel; this will make the external kernel module acpi_call obsolete
Support T400 running Coreboot via natacpi
Radio Devices

Support for switching NFC devices (new command nfc on|off)

TLP 1.4.0
Feature Highlights:

Audio

SOUND_POWER_SAVE_ON_AC: change default to enabled (Issue #495)
Battery

"Battery Features" renamed to "Battery Care"
Introduce plugins to support Battery Care for non-ThinkPads
ASUS laptops: stop threshold
Huawei MateBooks: start and stop threshold
LG Gram laptops: stop threshold at 80% aka "battery care limit"
Lenovo laptops: stop threshold at 60% aka "battery conservation mode"
Samsung laptops: stop threshold at 80% aka "battery life extender"
tlp-stat -b: show plugin, supported features, driver usage and related kernel module(s)
ThinkPads
Allow deactivation of the start threshold (START_CHARGE_THRESH_BATx=0)
Configuration

tlp-stat --cdiff: show configuration differing from defaults
PARAMETER+="add values": append values to a parameter already defined as intrinsic default or in a previously read file (Issue #457)
TLP_WARN_LEVEL: warn about invalid settings, configurable for background tasks and command line
Disks

AHCI_RUNTIME_PM_ON_AC/BAT
No longer experimental i.e. now enabled by default
Works only on disks defined in DISK_DEVICES
Works on NVMe (new), SATA/ATA and plugged in USB (new) disks
Works on SATA ports
DISK_APM_CLASS_DENYLIST: exclude disk classes from APM, i.e. you may now activate it for USB and IEEE1394 drives (Issue #523)
DISK_APM_LEVEL_ON_AC/BAT, DISK_SPINDOWN_TIMEOUT_ON_AC, DISK_IOSCHED: now also work when plugging in USB disks
Graphics

Add support for amdgpu (Issue #498)
Improve powerdown of unused GPUs with drivers amdgpu, nouveau, nvidia and without driver (Issues #488, #495, #498)
Operation Mode AC/BAT

Speed up system shutdown/suspend by not applying AC settings anymore
TLP_PS_IGNORE: add USB; allow to ignore multiple power supply classes
PCI(e) devices

RUNTIME_PM_ENABLE/DISABLE: permanently enable/disable runtime PM for PCI(e) devices based on address (independent of the power source)
Platform

PLATFORM_PROFILE_ON_AC/BAT: select platform profile to control system operating characteristics around power/performance levels, thermal and fan speed
Processor

CPU_HWP_DYN_BOOST_ON_AC/BAT: Intel CPU HWP dynamic boost (Issue #468)
tlp-stat -p: cpu1..cpuN omitted for clarity, use -v to show all
USB

USB_EXCLUDE_AUDIO: exclude audio devices from autosuspend (Issue #556)