I also own a 155H laptop using Linux Mint! Would you share your settings with TLP and LPMD? I am not getting not much longer battery life than Windows 11 on it after some tinkering, so seeing somebody else's setup may help a lot. Thanks!
My TLP and LPMD configs: https://gist.github.com/vient/f8448d56c1191bf6280122e7389fc1...
TLP: don't remember details now, as I recall scaling governor does not do anything on modern CPUs when energy perf policy is used. CPU_MAX_PERF_ON_BAT=30 seems to be crucial for battery savings, sacrificing performance (not too much for everyday use really) for joules in battery. CPU_HWP_DYN_BOOST_ON_BAT=0 further prohibits using turbo on battery, just in case.
LPMD: again, did not use it much in the end so not sure what even is written in this config. May need additional care to run alongside TLP.
Also, I used these boot parameters. For performance, I think, beneficial one are *mitigations, nohz_full, rcu*
quiet splash sysrq_always_enabled=1 mitigations=off i915.mitigations=off transparent_hugepage=always iommu=pt intel_iommu=on nohz_full=all rcu_nocbs=all rcutree.enable_rcu_lazy=1 rcupdate.rcu_expedited=1 cryptomgr.notests no_timer_check noreplace-smp page_alloc.shuffle=1 tsc=reliable