Battery icon shows 255% even when battery not installed

HP dv-6c63NR Laptop. Recently (not sure when it started), the battery icon in the System Tray show 255% charge when the battery is installed or removed. I've rebooted multiple times and just finished a reset. Nothing changes, still shows 255% charge.

Any suggestions on how to trouble shoot this?

It was okay a week or two ago.

This laptop is in the Insider Fast stream and currently has 1903 18362.1. I could install a non-insider build on my 2nd HDD (I have a 500GB SSD boot and a 500GB HDD 2nd drive) as a test.

As 255% is FF (hex) - all 1's - suggests a certain kind of bug...

If you have a live boot disk, that should prove it's not hardware related.

You could also try a 3rd party battery monitoring program, but if that reads the same buggy info from the OS, might give garbage too.

Similar here, resolved:
Battery shows 255% - how is that possible when 100 is the max?? | AVForums

This is weird (and typical of when I submit a problem). I powered off the laptop. Put the battery back in, powered up and now it seems to be sort of working. First it shoed charging, now it shows 2 Hours 00 minutes to full charge. Two minutes later it says 1 hour 45 minutes to full charge.

I'll keep and eye on it and also check out the link you provided.

Thank you.

That's a LOT of percentages, how big is that battery anyways? (normally it just goes to 100%) but dude, 255% ? Now that's a very serious bug!

zbook said:

Consider using HP Hardware Diagnostics Windows to check HP hardware: (right upper area of this link)
HP PC Hardware Diagnostics | HP® Official Site

sp94947

Click system tests > system extensive test > click run once (run the test overnight)
Next day perform component tests as needed (some are interactive).
For the component test to check the battery: click component tests > power > battery check

Thanks Z, will do that. Right now it's working correctly as it did before. Currently says Fully charged (100%).

RingTailCoon said:

That's a LOT of percentages, how big is that battery anyways? (normally it just goes to 100%) but dude, 255% ? Now that's a very serious bug!

It's one of the Long term batteries with the bulge at the bottom. Since it use to last 4-5 hours, it should now last 10-12 hours

While you are doing the other tests, run one of these PowerCfg checks as well.

Code:

PowerCfg -energy -duration 0 -output D:\Desktop\EnergyReport.html

or

Code:

powercfg /batteryreport /output D:\Desktop\battery_report.html /Duration 1

{using a folder path of your own choosing}

Look through the results to find these entries and compare them to each other.
- Design Capacity
- Last Full Charge
And check the battery capacity stated on the battery label {which will probably match the entry for Design capacity}.
If these parameters make sense then it will help to confirm that you are looking at a Windows problem rather than a battery problem.

Denis

Report says:

Design capacity: 98235
Last full charge: 67687

So it sounds like it's only charging to about 2/3 of capacity. I was using it on battery earlier today and after 2 hours of web browsing mostly, it had dropped from 100% to 73%.I closed th elid and let it sleep and after another couple hours it's now down to 42%. I'm going to let it go until it either hibernates or shuts down then I'll plug it in and let it full charge then re-run the above command and see what it says.

The battery test from the HP diagnostics @zbook pointed me to peovided a lot of info too. I'll post that info as soon as I find it again.

Thanks.

Rich,

The last full charge reading [~70% of design charge] seems alright if the battery has been in use for some time. Since I started recording these readings, I have seen drops of between 10-25% over the course of a year but a lot depends on your battery usage patterns.
- The more you use battery power the greater the gradual drop.
- The cheaper the battery the greater the gradual drop in many cases. I have seen references to some battery cells being "grade A" cells and these have been more expensive but, if there was any truth to it, I would expect the computer makers to boast about all their expensive replacement batteries having "grade A" cells and thus being worth the money.
- Do note that a System Tray battery icon reading of 100% means 100% of what it is currently capable of charging and has nothing to do with design capacity. So "100%" merely means Last full charge achieved or that's all you can get nowadays.
- A couple of hours browsing resulting in 73% left seems alright [actively using a WiFi connection does drain batteries quickly but I know nothing of LAN connections these days].

Dropping from 73% to 42% over a couple of hours sleeping seems highly excessive. I have had four laptops since I started regular battery monitoring and, in general, sleep uses about 1% an hour. I know that there are some computers with sophisticated sleep modes that maintain internet connections and, whilst I know nothing about them, I would expect them to consume a lot more during sleep.

Some computer manufacturers say that allowing the battery to drain completely [to the limit of hibernating / shutting down in the normal way] every once in a while does help to "calibrate" the battery reading shown by Windows System Tray battery icon.
- Others say nothing on the subject.
- I think a lot of them simply do not know anymore - they might simply have given up researching the matter after the advent of Lion batteries made the whole thing less of a critical issue.
- Lion batteries do not have the 'memory effect' that many of us remember from NiCd / NiMh batteries.
- I once tried to research the matter but found no reliable guidance [after having dismissed online articles that seemed to me to be just trying to show off how much cleverer the authors were than other people and that therefore seemed to be unreliable].
- Allowing your battery to drain might or might not improve the Windows System Tray battery icon indication [the primary problem symptom you reported]. It might also improve the drop during sleep. If it does either of these things then that would be evidence that "calibration" is a real thing / infrequent full drains are a good thing [your powercfg battery reports would show you which of these was the case].
- Allowing your battery to drain might or might not also improve the Last full charge result. If it does then that might be evidence that 'memory effect' is a real thing with Lion batteries after all or it might merely be a fairly common bouncing around - I have often seen batteries jump up again by 5% and have sometimes [perhaps twice a year] seen individual low readings that are down 20%-ish from the previous charging but that then jumped up again to their routine level next time.

I though I'd post these thoughts now before your drain test and before you run the HP diagnostics so you will have some food for thought when you examine those results.

All the best,
Denis