Sudden crashing on battery

[ALDMJ]

My laptop recently started crashing without warning me of low battery power.  Then it has become worse  and started crashing when the battery is about 40-50% Again no warning so I lose work if not careful.  All hardware updates have been installed including BIOS. Low battery warning is set at 7%.  Battery Check says the battery is fine and about 89% of original charging.

Is there anything else I can try other than reinstalling windows or buying a new battery?

[WAWood]

@ALDMJ 

First off, this is most likely a hardware issue with the battery -- so why would you think that reinstalling Windows would do anything to fix a failing battery? All it would do is make matters worse because after that, Windows Update would fire up and lock up your PC for HOURS doing update after update after update.

You can check the battery to some extent using Powershell built into Windows 10. as follows:
1) Press Windows key + X
2) Click Powershell in the menu
3) Type powercfg /batteryreport

This will generate a report and if you scroll down, you will see Design Capacity and Full Charge Capacity ratings. If the Full Charge Capacity is less than 50% of the Design Capacity, it is faulty and needs to be replaced.

Also note the figure alongside the "Cycle Count". This tells how many times the battery has been fully recharged. A typical battery can handle around 500 charge cycles, but some will fail sooner than that.

If the battery checks out, then there is most likely an underlying hardware issue with the motherboard and we have no diagnostics we can provide you to check that out.

For this issue, you would need to contact an HP Repair or Service Center.

Since you live outside the U.S., here is a link to HP Service Centers, by Country/Region: https://support.hp.com/in-en/service-center

Good Luck

[ALDMJ]

Thanks.  I do think it is most likely hardware but I have had nothing but problems with this computer.  

I tried to do what you said but although Win X brings up the menu and I click powershell, nothing happens!

Now I notice that when plugged in the brightness keeps going up and down and looking at the battery indicator it seems to alternate between acknowledging  the mains power and then reverting to battery...still plugged in, weird.

I have tried via command and cannot run as administrator even though I am logged in on an administrator account.

[ALDMJ]

Finally got a battery report.  Capacity is approx 75% of design capacity according to that. Cycle count is "-" Weird again.

Any other suggestions?