CMOS 502 and Charger Plugged In Only

[Foam050797]

Dear Everyone

Good day!

I have some issue on my HP Laptop - 15s-du2034tx.

As I open the laptop it shows a message of CMOS Reset 502, and once I click enter button to proceed the laptop wont charge it only indicates plugged in. The battery percentage is always 0 %. It immediately shutdowns once the plug is remove. 

What I have done so far was to update the bios but nothing happens. I also tried to locate the cmos battery but found out that it doesn't have one.  

Can anyone help me.?

Thank you

[banhien · Accepted solution]

@Foam050797 

The specs of your machine is

            https://support.hp.com/au-en/document/c06701398

It does NOT have CMOS (or RTC) battery therefore it has to use main battery. Now looks like your battery is no longer available therefore causing error 502. 

You left the battery dead for too long, my suggestion you replace new battery now using part # L11119-855 which is N/A from HP. You can use part # to search online including eBay

Regards.

[KingGoblin]

My HP Stream was doing the same - no charging, shut off as soon as PSU is unplugged, and the 'CMOS reset 502' error on startup.

Ran HP battery check, and got this report:

"charged 0%; Primary battery: no battery - not detected.
re-insert battery and ac adapter to retest"

Instead of doing this, I opened device manager:  Checked S/W driver; got 'OK' report, so assumed H/W i.e. battery, issue:

IMPORTANT ! UNPLUG AND DISCONNECT YOUR DEVICE OR PC FROM THE MAINS SUPPLY BEFORE DOING THE FOLLOWING !

Me:
Removed rubber feet; took out 7 screws; levered case apart with my paperknife.

Found:
Li-ion battery: HP p/n 823908-2D1
also has 'PO02XL' on it and : "Replace with HP spare 824560-005"

Checked on 'net - New one is £35+ so I replaced top of case, and did this instead:

Here's what worked:

Step 01. Click on the Start Button

Step 02. Type "Device Manager" in the start search box & open the Device Manager

Step 03. Look for Batteries in the list and expand it by clicking on the + symbol on the left

Step 04. Right Click on "Microsoft ACPI Compliant Control Method Battery" & uninstall the driver

Note: This Battery driver will get re-installed automatically when you restart the Notebook again

Step 05. Now go to  Shutdown the Notebook / Laptop

Step 06. Remove the Battery and unplug the Power Adapter

Step 07. Press and Hold the Power Button for full 1 Minute

Step 08. Go ahead and put back the Battery and connect the Power Adapter

Step 09. Look for "Plugged In Charging" message on the Battery icon, or run the HP battery diag's check,

(Note: I did not remove or disconnect the battery, and it worked just fine anyway)

[Foam050797]

Thank You for the information Banhien.

Yes indeed upon reading the manuals there were CMoS nor RTC. 

I was just worried if it was really the main battery, because if it is not I am spending cash for improperly.

Anyways do you have a manual for HT03XL battery if there are instructions on how to test or charge it externally without using the laptop.

Thank you

[Foam050797]

I tried to ran the hp battery check and the result was error. Not the same with you will it be okay if I try to do your steps on uninstalling the driver?

Thank you

[KingGoblin]

Hi,

You need to uninstall then re-install the battery charging driver - because there is no CMOS, or Secondary backup battery in these pc models, once the big Primary Battery is totally discharged, the settings for it are lost.

This is what happened to mine - I left it discharged over months and when re-connecting the charger, got the symptoms I described above: CMOS reset 502.

I too was not happy to spend money on a new battery - this would not have solved the charging problem anyway since it turns out to be a CMOS 502 error, only a software reset will cure this. To do that, you must make the system re-load the driver afresh upon startup, by deleting the old one - the update driver option will not work, because it's the CMOS settings for the driver that are gone.

Do this exactly as described in the sequence 'Here's what worked:' above using device manager, and don't miss out the 1-minute power button part; this forces a hardware reset thet is required.

(Although it says to remove or disconnect Primary Battery, I did not do this and it solved the problem anyway. I'm not sure if this is applicable to every case, however.)

This Battery driver will then get re-installed automatically when you restart the Notebook again, and the CMOS reset 502 error will no longer appear, along with the message to contact HP you may have seen.

Run HP battery check once more, and you will see 'battery OK' and a charge percentage will start to count up.

If it doesn't solve it, then you may well be looking at a new battery, but you will have lost nothing by going to this software solution first.

[Foam050797]

Hi,

I did try to do your instruction, unfortunately it doesn't work. 

[KingGoblin]

Your fault was a little different, as when you ran HP battery check, you wrote that it showed 'error' rather than 'missing battery' as mine did.

I'm thinking that if it still shows the same 'error' result when you run it after the battery driver was re-installed, then it is looking like an actual battery fault.

Have you tried disconnecting then re-seating all the battery connectors then running HP battery check again?

If there is no change at all whatever you do then it looks as if the solution is, in fact, to get a new battery as the previous poster wrote.