AC adapter not detected, battery does not charge, Elitebook 850 G3

[Qzoomer]

Battery does not charge when AC adapter plugged in.  Charging indicator not lit.  Battery slowly discharging as I use the computer.  HP Support Assistant shows good battery, does not recognize AC adapter.  Updated Battery Health Manager BIOS to latest version, no change.  Charger connector appears intact with center pin.  Attempted BIOS update but was unable because updater did not detect AC adapter and battery is approx 40% at this point.  Voltmeter test on adapter output shows approx 20 vdc.  Adapter is cool, indicating not loaded.  Using correct HP AC adapter for this model computer.  Battery does not charge when computer left powered down and AC adapter plugged in overnight.   Any suggestions?

[NonSequitur777]

@Qzoomer,

Based on what you have already troubleshooted, I am very much inclined to suspect a defective charger.

A quality non-OEM HP 65 watt (HP p/n: 854055-003) replacement charger is dirt cheap: for less than $15 you can get a new charger here, for example: Amazon.com: 19.5V 3.33A 65W AC Charger Replacement for HP Elitebook 850-G3 840-G3 820-G3 745-G3 725-... -or even cheaper here, for example: AC Adapter Charger For HP EliteBook 820 830 840 850 G6 G3 G4 G5 G7 725 G3 G4 G5 | eBay.

Hope this helps.

Kind Regards,

NonSequitur777

[Qzoomer]

Thanks for your reply and sorry for the delay - I needed to do some more testing.  I do not think it is the AC adapter at fault, so I will give the complete story.  I would agree that the AC adapter is a likely culprit, but based on my testing described below, I think it must be something else.

The computer in question was purchased as a "refurbished" unit.  In fact it is the second one with the same problem.  When I notified the vendor about the first one with the problem, a replacement AC adapter was furnished by the vendor.  It did not help.  I was able to make tests with a known good similar model Elitebook.  The AC adapters supplied for the "faulty" computer worked just fine when connected to the borrowed computer.  The known good AC adapter from the borrowed computer did not charge the " faulty" computer.  I returned that computer to the vendor and it was replaced.  The replacement is not the same one as it has a different serial #.  I am experiencing the same problem with the replacement computer and today I was able to make the tests of the AC adapter with the borrowed computer.  The AC adapter I have worked fine in the borrowed computer.  The AC adapter from the borrowed computer did not charge the replacement computer.  All the AC adapters are the same part number which is the correct AC adapter according to HP documentation.  I find it somewhat improbable that two computers would exhibit the same problem.  I am asking if anyone knows of some software or hardware or BIOS setting that could cause this problem.  I can only do short tests on the computer as the remaining charge on the battery drops each time I use it.

[NonSequitur777]

@Qzoomer,

Interesting.  So, we can eliminate the 45 watt (or 65 watt -depending what model you have) charger as being defective.

Let's talk about your laptop battery.  According to the specs, it's an HP p/n: 800513-001 ("Battery (Primary) - 3-cell lithium-ion (Li-Ion), 4.08Ah, 46Wh (CS03046XL-PL)" or CS03XL battery model, such as this one: Amazon.com: CS03XL Laptop Battery for HP EliteBook 840 850 755 745 G3 G4 ZBook 15u G3 G4 Series 8005...:

Question: have you run HP's "Test the battery using HP PC Hardware Diagnostics (preferred method)" and: "Calibrate the battery manually" as found here: HP Notebook PCs - Testing and calibrating the battery (Windows) | HP® Customer Support?

Kind Regards,

NonSequitur777

[Qzoomer]

Thanks for your further suggestions.

As was stated in my original post, I did test the battery using HP Support Assistant and the battery passed that test.  HP Support Assistant did not recognize the presence of the AC adapter which was plugged in during the test.  I am reluctant to perform a battery calibration as the instruction says this could take a couple of hours and I doubt there is remaining battery capacity to run for that long.  I am a bit reluctant to do any other testing that requires a software download due to the limited remaining battery capacity.

I note that there is a third connection from the adapter to the computer in the form of the small diameter center pin on the connector which, on the adapter is labeled "sense".  Does anyone on the forum know exactly what this does?  One possibility I am considering is that this signal allows the adapter/charger to reduce output or shut down when it detects a fully charged battery via a signal to this port from the computer.  Might there be a hardware/BIOS/Software issue which is causing the adapter to shut down when it should not?   In particular could there be a software setting someplace that is causing this problem?  To me, that would better explain why I have had this issue on two separate computers.