Laptop battery won't hold charge, but the battery may not be the issue?
January 24, 2015 1:37 PM   Subscribe

Help me diagnose, because I'm not convinced that it's because the battery is completely/irreparably fried. I am computer hardware naive but would prefer to explore all diagnostic possibilities before purchasing a replacement battery, especially if that won't fix the issue.

This all started when the bottom half of my HP Pavilion dv7t-7000's case started to break at the right hinge, which is also the corner of the laptop where the AC power port is located. I ignored the problem with the broken case (shame on me, I agree) until one day the case completely popped apart at the right hinge AND the battery stopped accepting a charge from the a/c port at the same time. Battery continued to hold its charge until it ran out of power and died.

My partner, who is fairly computer hardware savvy and did diligent research before tackling this particular issue, took the laptop apart (removed keyboard, etc to get the case apart) and was able to fix the case so that I can now open and close it without issue. During this time, as far as I know, he did not directly remove/reinstall or touch the components of the a/c power port.

When he put the laptop back together, I discovered the laptop was, thankfully, able to power on again, but ONLY if it was plugged in. The battery no longer holds a charge if unplugged.

Partner has checked it out and swears up and down that he properly reinstalled all of the components he had to remove, including the ribbon cable. He thinks the battery was fried at some point during the laptop-case-finally-breaking incident, since it's right near the AC power port and it was plugged in at the moment that the case officially broke for good.

In summation, series of unfortunate events from A to Z: Laptop case/hinge broke and consequently the laptop ceased to accept power from the AC power cord, battery then held on to the last several minutes of charge it had before until it died, laptop components were then taken completely apart (except the screen/upper portion of case), case/hinge was fixed and laptop was put back together, now the same battery would accept the power from the AC again, but would no longer hold the charge if the AC power was removed. Laptop stays on as long as it's plugged in.

ALSO OF NOTE: The a/c power port is wobbly, meaning the a/c power cord input won't stay firmly inside the port. This was an issue when the case was gradually falling apart (it fit just fine before the case issue began) and continued to be an issue after the case was repaired. Partner recently fitted some kind of material inside the port to keep the power cord firmly inserted (I don't remember what the material was and can't make it out when peering inside). **I mostly bring this up since I think the loose a/c power cord may indicate something about how the power/charge issue started**

I'm not totally convinced that my partner's explanation (that the battery is fried) is the actual cause of the problem. Why? Because I admit that I am stubborn and also don't totally understand how laptop batteries function. In my mind, I want to believe that if the battery got fried when the case broke, it would have quit functioning altogether - you know, it would have gone from being 100% charged to a suddenly worthless battery that no longer communicated power to the laptop - rather than doing a slow fade until all remaining power had dissipated.

I want to make sure I understand what the issue may be before I drop money on a new battery. I understand this may require taking the computer apart again, but having some additional guidance (beyond YouTube "How to take apart the HP Pavilion DV7T-7000" videos) on how to diagnose this would be helpful.

Please provide any directions or ideas you may have about what may have caused the battery to stop holding a charge, and if it's as simple as replacing the battery; or if it's a problem with the a/c power port; or if I won't know until I try using a new battery, or take the laptop completely apart again.

Thank you in advance!
posted by nightrecordings to Computers & Internet (7 answers total)
 
1. these machines are junk. i know that might be a bit personal opinion and tangential, but seriously, they're some of the most horribly made machines out there

2. on a lot of modern machines the charger and the PMU/charge controller/dc-dc board/whatever in the laptop actually talk to eachother. it's either asked for or broadcasted "hey, what model of charger are you, what power can you supply, are you overheating?" etc. a lot of dells, and most HPs can seemingly tell quite a bit about the charger and what state its in. If the connection from the charging socket to the motherboard gets screwy it'll often fall back in to a sort of "limp home" mode like an automatic transmission in a car, and either refuse to charge or run in a low performance mode or both.

3. the battery could have gotten too discharged to recharge, or too discharged to recharge in crappy power mode as mentioned above.

Do you get any message if you power the machine on from being totally off about the charger? Just because you don't doesn't mean #2 isn't happening, i've noticed that mostly only nicer "business" laptops will actually say anything.

Personally i'd go on amazon and order a new charger AND a new battery. Try old charger + new battery, new charger + old battery, new everything. If it makes no difference return it all and you know it's the socket or a motherboard issue.

The case popping open and the charging jack getting messed with could have also partially damaged something near the socket on the motherboard. Some part of the charging or power management circuitry, popped a pin off of a pad on an IC that controls some bit of that, etc. It may very well be able to run on a charger battery, but not charge it now. I've seen that before, but i wouldn't give up immediately.
posted by emptythought at 1:57 PM on January 24, 2015 [2 favorites]


Response by poster: Emptythought - When powering on the laptop, I don't get any messages about the charger or battery or anything.

Also, this may be irrelevant, but totally forgot to mention that my a/c charger (one of those universal ones you can get at Best Buy) was also killed when the case officially broke, because after the case was fixed I couldn't get it to work. I replaced that with a PWR+ brand a/c charger, and that allowed me to power up the computer (as long as it's plugged in) but no go with the battery.

Sounds like I just need to try a new battery and if that doesn't work, it's the socket/motherboard and I'm screwed?
posted by nightrecordings at 3:02 PM on January 24, 2015


Help me diagnose ... HP Pavilion

You bought a really crappy laptop and now it's broken.

So at this point, you have a choice between continuing to throw money at your cheap crappy machine, which will just eat it and break some more; or you can replace it with something not made by HP or Toshiba.

If your problem were my problem, I'd ditch the HP in a heartbeat. Life's too short.
posted by flabdablet at 4:23 PM on January 24, 2015 [1 favorite]


Response by poster: I am aware that the laptop is a potato. But let's please save that discussion for when I make a post asking for everyone's opinion on what laptop I should buy next.

For now, just assume I'm okay with dumping money into this problem, if it means having a functional battery and a laptop that I can eventually sell on Ebay for a little more than I could if the battery were non-functional. As I stated in my post, I'm looking to understand how to better diagnose this problem.
posted by nightrecordings at 5:00 PM on January 24, 2015


I agree with you that it's more likely a problem with the charging mechanism rather than with the battery. Personally I would guess it was damage caused by the case warping when the hinge broke.

First, leave it powered off, plugged in, with the battery in, overnight. This will diagnose "slow charging" vs "not charging".

Then inspect for physical damage... When you remove the battery does the inside of the battery compartment seem intact? Are all of the metal contacts lined up properly? (Also give them a quick wipe with a rag or paper towel or something to get rid of anything that might be impeding them). If you can't see anything in the battery compartment, it's probably something internal, which is really not worth the money to repair.

If you really need it to operate on battery power, you can get an external battery charger that charges without the laptop, but they're not cheap and...well, agree with the above re: your laptop is not worth it.
posted by anaelith at 5:16 PM on January 24, 2015


If the time between you running the battery dead and later trying to charge it was more than a week or two, it is not at all unlikely the battery pack's protection circuit tripped and will now refuse to accept a charge. This is because rechargable batteries discharge themselves while not being used at a rate around 2-4% per day when they are outside their optimal storage charge (40-70%), and it is worse the warmer they are. Also, the protection circuit itself uses a small amount of power.

Generally speaking, when the laptop tells you it has 0% remaining there is actually somewhere between 5 and 10% in the actual cells that make up the battery pack. Some packs have a little reset button on them that you can press to reactivate them if they haven't gotten so low that the protection circuit in the individual cells has tripped. If you can find something like that on yours, take the battery out after the laptop has been on the charger a few minutes, press it for a couple of seconds, and plug it back in overnight and you might just revive it. Not likely, but it's possible.

The reason for all the protection circuitry, by the way, is that trying to charge a lithium ion cell once it has gotten too low is somewhat likely to cause venting with flame. Same if they get inadvertantly overcharged. Since the individual cells have their own protection and the pack's internal logic should prevent it from dumping too much current into the cells, it's not actually very likely to happen if you do manage to reset the pack's protection. Still, it would be best to not try to charge it on or near anything flammable if you do try to revive it.

On the bright side, even if it doesn't work, you may have some perfectly good cells in that pack that you or someone else could use with an RC plane or whatever. It's likely at least some could be revived with a proper external charger, a bit of luck, some foolhardiness, and proper care to avoid burning down the house. ;)

Really, the easiest way to diagnose the issue is to try a different, known good, battery pack. Good return policies (or knowing someone with a laptop that has a compatible battery) are your friend here.
posted by wierdo at 9:22 PM on January 24, 2015


Also, this may be irrelevant, but totally forgot to mention that my a/c charger (one of those universal ones you can get at Best Buy) was also killed when the case officially broke, because after the case was fixed I couldn't get it to work. I replaced that with a PWR+ brand a/c charger, and that allowed me to power up the computer (as long as it's plugged in) but no go with the battery.

I have experience with these, with this exact issue... and with people bringing machines to me(and my dad calling me up in the middle of the day to drop off coworkers personal machines at my office to take a quick look at... ugh).

You want an HP charger, that says HP on the bottom. Remember my spiel above about the laptops controller communicating with the power brick? it doesn't like these chargers.

I would, at this point, assume that the battery AND machine are fine until you test with a real, OEM hp charger.

One of the totally brandless ebay chargers almost burned my house down, but somehow i hate these targus/generic universal/PWR+ chargers even more since they always tend to do this half-working thing.

If there's a PC recycling shop in your town, take the machine down there and see if you can try it out with one of the HP chargers they'll have in their MASSIVE bins of hp chargers. Look up which ones are compatible online first and then just try one.

I really bet it's the stupid universal/generic charger screwing you over here. I'd be SHOCKED if that didn't resolve the issue. Every time someone has had not charging+generic charger, using a real brand name charger like the one that came in the box worked. I especially believe this since it just "suddenly stopped charging". I think the drop was a red herring, at this point. Especially since it killed the charger, too.

You want this. They're common as hell. Every time i go in to a goodwill, there's one in there. any 19v HP brand charger that puts out 3.33amps or MORE will work(some of the gaming models, etc have higher current ratings but are just the same thing with the same logic circuitry).

Having looked it up and seen that it takes that charger, i can tell you for sure there's that laptop-charger communication logic going on here because i've owned several, and serviced HP systems that also used that charger(and would occasionally whine at me that my charger was no good after the cord was damaged some or it got partially unplugged accidentally or whatever).

If a real HP charger doesn't help, then you move on to motherboard damage or battery problems.
posted by emptythought at 4:02 AM on January 25, 2015


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