Note this a FYI issue related to recent dell-laptop kernel driver changes. The dell-laptop driver recently got support for the charge_control_start_threshold / charge_control_end_threshold power-supply attributes, but with a twist.
The Dell firmware also has a battery-mode setting represented by a charge-types attribute: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d24bf99214b199c25f9c2cb04b3a4993d1c7ab60
And the start / end thresholds are only applied when this is set to custom.
So when there is a /sys/class/power_supply/BATx/charge_types attribute on a power-supply class device and the list of possible values in that attribute contains "Custom" then PowerDevil will need to take this into account.
For upower the plan is to report start/end thresholds of 0 (disabled) for start and 100 for end when charge_types contains Custom but is not set to Custom and to set charge_types to Custom when writing the thresholds.