Light use on my laptop has always given me around 3.5hrs on a full charge with mildly loaded system. Recently this has dropped to a little over 2hrs. I thought maybe it’s the age of the laptop and the battery getting towards end of life as it is fairly old and I very rarely run off the battery, which I hear isn’t so good for Lithium batteries. Then the other day I had to do something using my Ubuntu partition (one particular software stopped working as expected in Manjaro, I think due to the 3rd party addons I use not being compatible with later versions) and it ran 3.5hrs quite happily. As you’ll see below inxi shows the battery as being at 100% health too. So it seems the battery probably isn’t actually the issue.
I can be fairly certain it is not the kernel version as I have a separate issue with later kernels so I am booting into the one I was using when I believe I had observed good battery life. I will try the one below it too (which is the oldest I have installed.) Tested with same programs running, WiFi disabled, made sure both are running Powersave mode in the CPU driver (which is the pstate driver in both instances as 5.4 is before the changes to this.)
(For completeness I’m running 5.4-rt as it mostly runs good. 5.9-rt gives me issues which caused me to revert to my previously installed kernel. I have tried 5.12-generic an 5.11-lqx but not tested the battery with them as they give me the same issue as 5.9-rt. I have 5.2-rt installed and will check how it performs on battery tomorrow (it’s quite late where I am so wont be able to today.)
$ inxi -Fxzc0 System: Kernel: 5.4.106-rt54-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0 Desktop: Xfce 4.16.0 Distro: Manjaro Linux base: Arch Linux Machine: Type: Laptop System: Hewlett-Packard product: HP EliteBook 840 G2 v: A3009D410303 serial: <filter> Mobo: Hewlett-Packard model: 2216 v: KBC Version 96.5B serial: <filter> UEFI: Hewlett-Packard v: M71 Ver. 01.27 date: 07/12/2018 Battery: ID-1: BAT0 charge: 14.8 Wh (46.4%) condition: 31.9/31.9 Wh (100.0%) volts: 12.7 min: 11.4 model: Hewlett-Packard Primary status: Charging CPU: Info: Dual Core model: Intel Core i7-5500U bits: 64 type: MT MCP arch: Broadwell rev: 4 cache: L2: 4 MiB flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 19166 Speed: 961 MHz min/max: 500/3000 MHz Core speeds (MHz): 1: 961 2: 856 3: 938 4: 952 Graphics: Device-1: Intel HD Graphics 5500 vendor: Hewlett-Packard ZBook 15u G2 Mobile Workstation driver: i915 v: kernel bus-ID: 00:02.0 Display: x11 server: X.Org 1.20.11 driver: loaded: intel resolution: 1920x1080~60Hz OpenGL: renderer: Mesa Intel HD Graphics 5500 (BDW GT2) v: 4.6 Mesa 21.0.3 direct render: Yes Audio: Device-1: Intel Broadwell-U Audio vendor: Hewlett-Packard driver: snd_hda_intel v: kernel bus-ID: 00:03.0 Device-2: Intel Wildcat Point-LP High Definition Audio vendor: Hewlett-Packard driver: snd_hda_intel v: kernel bus-ID: 00:1b.0 Sound Server-1: ALSA v: k5.4.106-rt54-MANJARO running: yes Sound Server-2: sndio v: N/A running: no Sound Server-3: JACK v: 1.9.18 running: yes Sound Server-4: PulseAudio v: 14.2 running: yes Sound Server-5: PipeWire v: 0.3.26 running: no Network: Device-1: Intel Ethernet I218-LM vendor: Hewlett-Packard driver: e1000e v: 3.2.6-k port: 5080 bus-ID: 00:19.0 IF: enp0s25 state: down mac: <filter> Device-2: Intel Wireless 7265 driver: iwlwifi v: kernel port: ef80 bus-ID: 03:00.0 IF: wlo1 state: up mac: <filter> Drives: Local Storage: total: 3.64 TiB used: 2.87 TiB (79.0%) ID-1: /dev/sda vendor: Samsung model: SSD 850 EVO 4TB size: 3.64 TiB Partition: ID-1: / size: 59.83 GiB used: 38.23 GiB (63.9%) fs: ext4 dev: /dev/sda3 ID-2: /boot/efi size: 496 MiB used: 49.9 MiB (10.1%) fs: vfat dev: /dev/sda1 Swap: ID-1: swap-1 type: partition size: 15.26 GiB used: 0 KiB (0.0%) dev: /dev/sda5 Sensors: System Temperatures: cpu: 50.0 C mobo: 0.0 C Fan Speeds (RPM): N/A Info: Processes: 209 Uptime: 1h 40m Memory: 15.04 GiB used: 2.55 GiB (16.9%) Init: systemd Compilers: gcc: 10.2.0 Packages: 2113 Shell: Bash v: 5.1.0 inxi: 3.3.04