Battery drained at 50%

[djd3mo]

Hi !

Pavilion dv7-1245dx - january 2009

starting june 2011 laptop keeps dying at about 50%

hp assistant battery check - status OK

powercfg report:

Battery: Battery Information

Battery ID - Hewlett-Packard

Primary Manufacturer - Hewlett-Packard

Serial Number  

Chemistry - Lion

Long Term - 1

Design Capacity - 73440

Last Full Charge - 63288

Complete charge/discharge power management calibration procedure tried several times - no visible change.

Every now and then I get a "plugged in, not charging" message

All of the above while using Win7.

Right now booted in Ubuntu 10.10, charging normally. I am waiting for a full recharge to try and reboot Ubuntu batt only.

Thanks for any useful thoughts

[erico]

I recommend that you calibrate your notebook battery. The calibration procedure will reset the displayed 100% to actual capacity. Actual capacity of an Lion battery does change over time.

Best regards,

erico

[djd3mo]

Well, I've tried that too (the one with the PC in use), didn't work. But, as I stated before, the HP Battery Check shows Status: OK. It doesn't show Status: Calibrate. I've tried reflashing BIOS, nothing there either. Right now I am using Ubuntu, no AC power, slowly draining the battery and hoping it's not going to stop suddenly.

[erico]

try a manual calibration.

Best regards,
erico

[djd3mo]

This is exactly what I have tried and no difference:

Calibrate the battery while PC is in use

A calibration cycle requires that the battery be completely charged and then completely discharged. During the calibration cycle, the power management properties must be disabled to allow the battery to completely discharge.

Follow the steps below to calibrate the battery power meter readings.

1. Connect the AC adapter and allow the battery to charge to 99% - 100% of capacity.
2. Disconnect the AC adapter from the notebook PC.
3. Click Start , enter power in the Search field, and then selectPower Options from the list.
4. Select Create a power plan from the left sidebar.
5. Click in the Plan name field and type Calibrator . Then, press Enter .
6. Select Never for all topics in the On battery column.
7. Click Create to accept the values and force the battery to consistently discharge.
8. Allow the battery to discharge completely until the notebook PC shuts down.
     NOTE:  The battery power meter is now calibrated, and the battery level readings should be accurate.
9. Connect the AC adapter and restart the notebook PC.
10. After calibration, return to the Power Options dialog box (Step 3) and select your default power plan setting.

[djd3mo]

And now I've tried the second one:

<<

Calibrate the battery while PC is not in use
A calibration cycle requires that the battery be completely charged and then completely discharged. The calibration may take one to five hours, depending on the age of the battery and the notebook configuration.
Follow the steps below to calibrate the battery power meter readings.
 NOTE:  Do not use the PC during the calibration cycle.

Shut down the notebook PC.
Connect the AC Adapter and charge the notebook PC until the battery charge light is green, indicating that the battery is completely charged.
On some models the battery light glows white, and on other models the light turns off when fully charged. See your model's User Guide.
Restart the notebook.
Press F8 several times when the HP logo appears.
When the Windows Advanced Boot Options menus displays, use the Up and Down arrow keys to select Safe Mode and then press Enter .
When the Windows Advanced Startup Menu displays, select the Startup in Safe Mode option.
Disconnect the AC power adapter from the notebook PC.
Allow the battery to discharge completely until the notebook PC shuts down.
The battery is now calibrated, and the battery level reading on the power meter should be accurate.

>>

No matter what I try, my laptop drops dead at about 50%. If I try to restart it with the AC adapter disconnected, it doesn't last more than 5 seconds and dies again. When I plug it back in and restart, the battery meter shows 50% charged.

All in all, the battery is supposed to be 86.7% of its original capacity (the powercfg report says so and Ubuntu says so too), the HP assistant says that the batt's Status is OK, but, at the same time, after numerous recalibrations, something cuts the power suddenly (no matter what OS) when it reaches 50%.

Well,... I am puzzled and don't know what I should try next (besides a new battery).

[erico]

I believe that you are going to have to accept the dimished capacity of the battery.

2+ years isn't bad for longevity. Some people get far less. I would consider replacing the battery with a new one. There is no requirement to use an HP original battery and there are plenty of aftermarket lion batteries on the market for your notebook.

Best regards,

erico

[djd3mo]

Not before I try my battery on another laptop.

It's weird because it didn't give me any clues, it suddenly started happening about a month ago and also because every software tells me that the battery is OK (86% of its original best).

Thanks for your help !

[djd3mo]

Solved ??? How is this solved ? I raised the issue and I got back no real answer. You could as well told me to buy a new laptop. That would also solve my problem ! Don't count it solved cause it's not ! Maybe someone else would find a solution.

[erico]

Notebook batteries have their limitations. Their performance is based on the way they are used, charged, stored and the ambient temperature. The performance option setting in an operating system will always have a great effect on how long a charge lasts.

I suggest a bit of light reading on Lion and smart batteries.  It will help you to have a better understanding of how they operate and how performance of a battery degrades over time.  

Best regards,

erico