Jump to content


 


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.


Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.

Photo

New laptop battery doesn't charge


  • Please log in to reply
8 replies to this topic

#1 ChopItUp

ChopItUp

  • Members
  • 17 posts
  • OFFLINE
  •  
  • Local time:10:09 AM

Posted 11 March 2011 - 12:26 AM

I recently acquired an HP Pavilion 8140US laptop with a dead battery. The computer works well with the AC adapter, but dies as soon as the plug is pulled, so I bought a new 12-cell battery from one of the multitudes on Ebay that offer them. When it arrived 2 days ago I installed it, connected the AC adapter, and booted up (Windows XP Pro, freshly installed about a week before) and checked the battery monitor, which showed about 60% charge. I left it running for a while and saw the charge level rise to 99%, but it never hit 100, even after another couple of hours. I then unplugged the AC adapter and over the next 15 minutes or so the battery monitor showed the charge level drop way back down, I think to about 10% (I don't remember exactly). Since then I've left the AC connected continuously, but the charge level never goes above 10%. If I unplug the AC while it's running it immediately goes down to about 2%, and after 5 minutes or so the computer shuts off.

I don't know if the new battery is at fault or if it's the laptop. I would be inclined to think that the new battery is good, except that I had a bad experience a couple of years ago with another Ebay laptop battery, in which case I was sent 2 dead ones before finally getting a third one that actually worked at all. I'm wondering if there's way way to know for sure where the problem lies? Do I send back the battery and hope for a good exchange? Is there some way to test the laptop battery charging circuit?

BC AdBot (Login to Remove)

 


#2 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,377 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:02:09 PM

Posted 11 March 2011 - 01:37 AM

Did you check the battery to make sure you took any contact protection tabs off it it first before putting it into the laptop?

Does the battery appear used at all?

Are you sure the battery is making a solid contact with the laptop connections?

It is not uncommon for a laptop battery to drop down quickly during the first few charging cycles, but it should at least charge to 100% regardless.

If in doubt send it back.

By the way, does the seller have a high buyer rating?

Bruce.
Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 37 Years as an Electronics Repair Technician, to Which I am Currently Retired From.

I Am Currently Using Windows 10 Home Edition.

As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

#3 ChopItUp

ChopItUp
  • Topic Starter

  • Members
  • 17 posts
  • OFFLINE
  •  
  • Local time:10:09 AM

Posted 12 March 2011 - 03:15 PM

Thank you for the reply.

To answer your questions:
- Yes, there was no protective covering on the battery connector.
- No, the battery looks brand new.
- I can't say for certain that the contact between the computer and battery is solid on each pin because I can't actually see them engage very well. However, there is nothing that appears bent or faulty that would make me suspect that the connection is poor.
- The seller's rating is 99.7% and the battery has a 1 year warranty.

I located a pinout diagram for an HP DV9000 battery connector, which I realize may be different but is hopefully the same, and I measured the battery's voltage between the ground pin and the supposed Batt+ pin and got 16.5 volts. The battery's rated voltage is 14.8 volts.

I'll go ahead and inform the seller that I wish to exchange it for another and see how it goes. Hopefully the fault is in the battery and not in the laptop's charging circuit. As I said already, the only other time I bought a replacement laptop battery (for an HP Omnibook XE2) I was sent 2 bad ones before finally getting a working one. However, in that case I had owned it since long before the original battery's life expired so I had confidence in the charging circuit.

#4 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,377 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:02:09 PM

Posted 12 March 2011 - 04:12 PM

Thank you for the reply.

I located a pinout diagram for an HP DV9000 battery connector, which I realize may be different but is hopefully the same, and I measured the battery's voltage between the ground pin and the supposed Batt+ pin and got 16.5 volts. The battery's rated voltage is 14.8 volts.

The rating of 14.8 Volts is when the battery is under an actual load, even though you may have had a meter hooked up to the battery, the battery was not under any load, so the reading will be much higher on the meter because of this.

Same with automobile batteries, they can show +/-16 volts on a meter, even though they are rated for +/- 13 volts. When under load the readings are different. :thumbup2:

Now this is not to say there is not a problem with the charging circuit, there is no way the average computer user can trouble-shoot this circuit for problems.
Unless you have electronics repair knowledge, that would best be left up to a computer repair shop.

Bruce.
Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 37 Years as an Electronics Repair Technician, to Which I am Currently Retired From.

I Am Currently Using Windows 10 Home Edition.

As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

#5 ChopItUp

ChopItUp
  • Topic Starter

  • Members
  • 17 posts
  • OFFLINE
  •  
  • Local time:10:09 AM

Posted 13 March 2011 - 12:05 AM

As a matter of fact, I do have electronics repair knowledge. It's what I do for a living, though I don't do a whole lot actual PC repair; my forte is embedded systems. I see from your signature that your electronics experience exceeds mine by about 20 years, so I know I wouldn't be able to grasp everything you could throw at me. But at least I'm familiar with the loaded/unloaded battery readings. :thumbup2:

I might be able to get a laptop battery connector from a friend who's parting out an HP DV6000, and if the connectors are the same as the DV8000 I'll try building a breakout cable so I can take some in-circuit battery measurements. Maybe that would enable me to properly identify the root of the charge problem.

#6 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,377 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:02:09 PM

Posted 13 March 2011 - 12:16 AM

Your back-ground may be useful in repairing this laptop, this is an Hewlett Packard computer Pavilion 8140US, I believe I can locate an on-line .pdf service manual for this laptop, would that be helpful to you?

Bruce.
Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 37 Years as an Electronics Repair Technician, to Which I am Currently Retired From.

I Am Currently Using Windows 10 Home Edition.

As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

#7 ChopItUp

ChopItUp
  • Topic Starter

  • Members
  • 17 posts
  • OFFLINE
  •  
  • Local time:10:09 AM

Posted 13 March 2011 - 12:48 AM

Yes, it's an HP Pavilion dv8140US (I just noticed that I left the dv out of the model number in my original post and the thread description).

I was able to locate the Maintenance and Service Guide for the Pavilion dv8200 and dv8000 (HP Document Part Number: 403248-002), but it didn't have any specific troubleshooting information for the battery, other than instructing to try it in another computer. If you have access to any better documentation than this I would certainly be interested in having a look!

#8 MrBruce1959

MrBruce1959

    My cat Oreo


  • BC Advisor
  • 6,377 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Norwich, Connecticut. in the USA
  • Local time:02:09 PM

Posted 13 March 2011 - 12:55 AM

You may have downloaded that from the first source I would have gone to for the manual which is the Hewlett Packard web site.

They did not have a maintenance manual for the dv8140US model number?

I haven't looked, but perhaps they are all the same computer except with a different branding on them.

Bruce.
Welcome to Bleeping Computer! :welcome:
New Members: Please click here for the Bleeping Computer Forum Board Rules
 
My Career Involves 37 Years as an Electronics Repair Technician, to Which I am Currently Retired From.

I Am Currently Using Windows 10 Home Edition.

As a Volunteer Staff Member of Bleeping Computer, the Help That I Proudly Provide Here To Our BC Forum Board Membership is Free of Charge. :wink:

#9 ChopItUp

ChopItUp
  • Topic Starter

  • Members
  • 17 posts
  • OFFLINE
  •  
  • Local time:10:09 AM

Posted 13 March 2011 - 12:38 PM

I did a search by model number on the HP site and the only service manuals that came up were the dv8000/dv8200 and one that's just the dv8000.

I guess they're essentially the same model with slight variations. My BIOS says it's a dv8000, as does the tiny placard on the corner of the monitor, however the information tag on the bottom shows the model number dv8140.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users