Dell Power Manager - Not working through WD19 Dock Station

Additionally I confirm the following:

• I have updated the WD19 to the latest version using the Dell Firmware Update Utility. (05.04.03 / 01.00.00.04)
• Dell Power Manager running latest version: 3.6.0 
• Event Log / Application / [filter by: dellcommandpowermanager] contains no error/warning log entries except for: Information from DellPowerManager.exe Message: Client [3.6.0.12] Server [3.6.0.12]
• The Windows Power Plan selected is "Dell", not "Balanced".
• There are no domain admin policies in use on my computer because it is not joined to a domain so all battery settings are available to choose, however none of them having any effect as mentioned in my previous message.
• Again, if i disconnect the WD19 docking station by removing the USB-C cable(the power cable), and instead use the default normal power cable, then only does Dell Power Manager function to do what it is supposed to do. 

I am cognisant of wanting to extend my computer's battery life before having to replace it. 

I want to continue, needing only to unplug x1 cable, instead of x6 cables & peripherals. 

Thank you.

Understood.

I'll venture into the BIOS as instructed and report back to you soon. Thx!

@jphughan  Here's the results:

--Bios--
The BIOS battery policy was set to "Primarily AC use" which did not match DPM policy of 50%<>90% and had to set it to match, then saved and re-entered BIOS.
I've observed charging using only USB-C PD going from 88% to 90% and the charging status then changed to "idle" - as it should. Nice!

--Win10--
Back into O.S there is a new twist.
Continuing with the USB-C DP as the only power source, I can see that DPM is reporting: "Charge Status: 90% available, plugged in, not charging".

I then fired up a game to switch on the GeForce MX250 in order to speed-up discharge, however the battery level in DPM and on the taskbar remained stationary at 90%.

This means it is not "not charging", it is charging and kept at 90%.

Then I unplugged the USB-C cable coming from the WD19 and the DPM Charge status changed to:"90% remaining". And the % went down to 89% and declining which means it is now discharging.

I then plugged in the barrel-type charger only, and the Charge Status changed again to "...plugged in, not charging". To my suprise, the % level again was locked in 87% and is not discharging as I thought it would.

Now, I've set this custom policy the same day I received the docking station and before this, the setting was always set to "Adaptive". Therefore I have to conclude that neither the DPM Policy, nor the BIOS Policy, is actually doing what it is supposed to do which is to DISCHARGE down to 50%.

No matter what the power source is, but rather IF a power source is connected, discharging does not occur. Subsequently referred to as a Bug, yes? 

Where does one report this to ?

@Cyberflake  Interesting that DPM didn't align with the BIOS settings.  That seems like a bug, although it likely accounts for the inconsistent behavior you're observing.

In terms of your findings, playing a game while connected to AC power should NOT speed up the discharge of your battery.  It seems like you might not understand how the maximum and minimum charge levels work.  If you set both maximum and minimum charge levels, then whenever the system is connected to AC power and the battery level is between those values, the battery is neither charged, nor kept topped up, nor actively discharged.  It is kept idle, which means it will be allowed to "self-discharge" down to the minimum value.  If you have a battery at 90% charge level and never run it on battery, self-discharging down to 50% would take MANY days, and playing a game would NOT speed that process up because again, the system is not actively drawing from the battery to run itself.  It's drawing all of the operating power it needs from the AC source, but NOT sending anything to the battery.  Your battery remaining at 90% during what sounds like a relatively short test window would be expected, since again dropping from 90% to 50% purely on self-discharge takes quite a long time.

Ah, okay that clears things up then!

"Self-discharge", like switching off your mobile phone, placing it in your drawer and let it bleed down slowly over weeks. 

Interesting. 

Thank you for your time to respond.

@Cyberflake  Exactly right, and all else being equal, higher quality batteries have slower self-discharge rates.

@jphughan 

In conclusion:

The DPM question I initially posted was redundant as there are, in fact, no issues except for the BIOS and DPM settings not kept in-sync.

In order to extend longevity of the battery, one should try to...(correct me if i'm wrong):

• Increase the time between charge-cycles by allowing the battery to self-discharge.
• Charge up to 80%.
• Keeping the computer environment cool as apposed to inside a hot car in the sun.
• Any other tips ?