Timeline for Is this HP laptop battery — that has been fully drained — safe to use?
Current License: CC BY-SA 4.0
13 events
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| Feb 25, 2020 at 0:22 | history | edited | Giacomo1968 | CC BY-SA 4.0 |
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| Feb 24, 2020 at 2:13 | comment | added | Jeff | @Moab I suspected the same. At the time I haven't read up on lithium, so I just followed their instruction. Later I read that this pretty much puts it in sleep mode. | |
| Feb 23, 2020 at 13:13 | comment | added | Moab | "I have no idea why HP would have told you to run it down to zero " That is how they sell batteries, they have done this for many years, worst thing you can do on an old lion battery. | |
| Feb 23, 2020 at 12:46 | comment | added | Jeff | Well actually the voltage from my current battery comes directly from HP's battery diagnostic test. | |
| Feb 23, 2020 at 12:13 | comment | added | Tetsujin | As @Tonny has already mentioned, you cannot measure the voltage of a battery under load without some pretty sophisticated equipment. Just slapping a meter over the unloaded terminals will give you no clue at all, the figures are false. Don't rely on them. Recycle & replace the entire unit[s]. | |
| Feb 23, 2020 at 11:28 | vote | accept | Jeff | ||
| Feb 25, 2020 at 14:19 | |||||
| Feb 23, 2020 at 11:19 | comment | added | Jeff | I was under the impression that lithium batteries "lose" voltage as it ages, not gain. Is this normal? So one is 4.03, another 4.06, which seems normal, and the bad one is 4.16 when not charging. I recently replaced the fuse on this battery from another laptop. This one is 11.1v while the one I took it from was 10.8v. I thought they would be the same, but could they use different fuse? And could this fuse somehow affecting the voltage? Thanks! | |
| Feb 23, 2020 at 11:16 | comment | added | Jeff | Thank you, you guys. Yeah, I think you're all correct. It's not worth the risk. Had the cells been in a laptop I'm currently using and still keeping it charged, I might try it. But 3 years drained and sitting on the shelf, I think that's just asking for bad tings to happen. If possible, I'm wondering if I can ask another similar question so I don't have to start a new topic. My current battery stops charging at 54%. I checked the voltage, apparently 1 of them is too high. So basically it won't charge if the whole set reaches 12.6V (around 12.55). to be continued... | |
| Feb 23, 2020 at 11:01 | comment | added | Tonny | @Jeff Continued... And in a special fire-proofed shack next to the normal workshop. Please: Don't try this at home !!! | |
| Feb 23, 2020 at 10:59 | comment | added | Tonny | @Jeff I understand your reasoning, building a good battery pack out of 2 bad ones, but I strongly advise against it. First: voltage doesn't mean anything with these cells, because you measure that without any load applied. So there is a high chance they are still bad. Second: rebuilding battery-packs can be done, but leave it to the professionals. Too much room for bad results (fire, explosion). I happen to know a such professional, but even he (20 years of experience and a well equipped lab/workshop) is very careful and only does it with a safety-glass screen between him and the cells. | |
| Feb 23, 2020 at 10:57 | comment | added | Tetsujin | Please don't guess with something that could potentially burn the house down. Recycle & replace with new. Any Li-ion which has dropped below 2v for even a short time can develop copper shorts internally. These cannot be seen, but will result in what the manufacturers like to refer to as "rapid disassembly" but we'd call 'venting with flame' - Ref: batteryuniversity.com/learn/article/safety_concerns_with_li_ion | |
| Feb 23, 2020 at 10:43 | comment | added | Jeff | Thanks for the reply. Yes, I was really upset with HP when they suggested I do that. They said that is suppose to "calibrate" my battery, but after leaving it over night, it just went dead. I'm thinking of salvaging the cell b/c my current battery is showing similar signs, it lost 50% of capacity and I'm thinking 1 pair of the cells are dead. I'm hoping to replace it with one of the 2 pair of this one that is having 4V. Some say only voltage matters, so they should be good. But they have been sitting there for 3 years, I'm not so sure. | |
| Feb 23, 2020 at 10:39 | history | answered | Tetsujin | CC BY-SA 4.0 |