Re: Hint on reviving old rechargable batteries
Typically, a bank of 18650 Li-ion batteries is used in laptop power packs. Each cell is nominally 3.7 V when fully charged. Circuitry in the cells puts them into "sleep" mode at about 2 V. This can happen with any Li-ion battery not used for a long time. All that is needed is a "kick start" at about 2 A for a few seconds to get them above the threshold and wake them up. Some battery chargers will do this, most won't. One needs to be cautious - if it is overdone, there is a risk of explosion. I have done this with 18650 cells from a "defunct" laptop power pack & used them in emergency lights. Also with mobile batteries. Alan C -Original Message- From: mike wilson Sent: 26 December, 2017 1:26 AM To: Pentax-Discuss Mail List Subject: Re: Hint on reviving old rechargable batteries I had a netbook, about four years old at the time, running on XP, that had a "dead" battery. No problem, as I would just run it on the charger. I changed the OS to UBUNTU and !suddenly! the battery could charge. Checking the charge history (which I could not do in XP) I found that the OS had checked the battery, found nothing wrong with it and proceeded to charge it. Clearly, there was something in XP preventing the charge sequence. You could argue that there was something going on to protect the computer but Occam's Razor suggests to me that it merely counted out time or number of charges and decided at that point that the battery was toast and refused to play. I think a truly dead battery is a very rare occurrence. On 25 December 2017 at 10:51 Alex Sarbu wrote: Indeed, "intelligent" chargers would detect "bad" batteries and refuse to charge them; and often you can jump-start them in a "dummy" charger. Apparently that's a feature. You could use the BC 900 to test or refresh the batteries (don't leave the charger unsupervised! - nor near flammable materials). I assume the old batteries had no signs of physical damage/leaks/corrosion. Alex On Tue, Dec 19, 2017 at 8:00 PM, Igor PDML-StR wrote: > > > I've discovered that NiMH AA batteries that were in the old Pentax DS > body > (remember those?) were completely dead. > I tried to put them in renown La Crosse charger (BC-900), and that > refused > to charge them. > > I was able to resuscitate them by putting them into a "fast" Duracell > charger, and then trying to start charging a few times by plugging that > charger into the power outlet. At first, that charger also refused to > charge > them, but after 3-4 attempts, the first pair started charging, and then > (after that pair was somewhat charged, so that I can put them in > BC-900), I > did 2-3 more attempts with the second pair, and it worked. > > I suspect BC-900 was a bit too gentle with the initial charge attempt. > But it is also possible that it could have worked if I tried a few more > times. > > I am not sure how well these batteries will work, the time will show. > But at least this allowed to charge them up. > > An alternative would be to use a 1.5 V power supply, but this trick was > simple enough. > > I thought this might be useful to somebody. > > > Igor > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Hint on reviving old rechargable batteries
My 9 year old Dell laptop stopped charging the battery after about 2 years of ownership so I've been running it off the power cable, although I did find an external charger on Ebay that allowed me to charge the battery unmounted from the computer. Inconvenient, but at least it enabled me to use the battery when needed. Then, 6 months ago the power cable stopped working completely. Luckily I found a cheap no-name replacement on Ebay - which immediately started charging the battery again. I should have ditched the original Dell cable 7 years ago and just got the no-name one then. Cheers Brian ++ Brian Walters Western Sydney Australia http://lyons-ryan.org/southernlight/ On 26 December 2017 at 10:26 mike wilson wrote: I had a netbook, about four years old at the time, running on XP, that had a "dead" battery. No problem, as I would just run it on the charger. I changed the OS to UBUNTU and !suddenly! the battery could charge. Checking the charge history (which I could not do in XP) I found that the OS had checked the battery, found nothing wrong with it and proceeded to charge it. Clearly, there was something in XP preventing the charge sequence. You could argue that there was something going on to protect the computer but Occam's Razor suggests to me that it merely counted out time or number of charges and decided at that point that the battery was toast and refused to play. I think a truly dead battery is a very rare occurrence. > On 25 December 2017 at 10:51 Alex Sarbu wrote: > > Indeed, "intelligent" chargers would detect "bad" batteries and refuse > to charge them; and often you can jump-start them in a "dummy" > charger. Apparently that's a feature. > You could use the BC 900 to test or refresh the batteries (don't leave > the charger unsupervised! - nor near flammable materials). I assume > the old batteries had no signs of physical damage/leaks/corrosion. > > Alex > > On Tue, Dec 19, 2017 at 8:00 PM, Igor PDML-StR wrote: > > I've discovered that NiMH AA batteries that were in the old Pentax DS body > > (remember those?) were completely dead. > > I tried to put them in renown La Crosse charger (BC-900), and that refused > > to charge them. > > > > I was able to resuscitate them by putting them into a "fast" Duracell > > charger, and then trying to start charging a few times by plugging that > > charger into the power outlet. At first, that charger also refused to > > charge > > them, but after 3-4 attempts, the first pair started charging, and then > > (after that pair was somewhat charged, so that I can put them in BC-900), > > I > > did 2-3 more attempts with the second pair, and it worked. > > > > I suspect BC-900 was a bit too gentle with the initial charge attempt. > > But it is also possible that it could have worked if I tried a few more > > times. > > > > I am not sure how well these batteries will work, the time will show. > > But at least this allowed to charge them up. > > > > An alternative would be to use a 1.5 V power supply, but this trick was > > simple enough. > > > > I thought this might be useful to somebody. > > > > Igor > -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Hint on reviving old rechargable batteries
I had a netbook, about four years old at the time, running on XP, that had a "dead" battery. No problem, as I would just run it on the charger. I changed the OS to UBUNTU and !suddenly! the battery could charge. Checking the charge history (which I could not do in XP) I found that the OS had checked the battery, found nothing wrong with it and proceeded to charge it. Clearly, there was something in XP preventing the charge sequence. You could argue that there was something going on to protect the computer but Occam's Razor suggests to me that it merely counted out time or number of charges and decided at that point that the battery was toast and refused to play. I think a truly dead battery is a very rare occurrence. > On 25 December 2017 at 10:51 Alex Sarbu wrote: > > > Indeed, "intelligent" chargers would detect "bad" batteries and refuse > to charge them; and often you can jump-start them in a "dummy" > charger. Apparently that's a feature. > You could use the BC 900 to test or refresh the batteries (don't leave > the charger unsupervised! - nor near flammable materials). I assume > the old batteries had no signs of physical damage/leaks/corrosion. > > Alex > > On Tue, Dec 19, 2017 at 8:00 PM, Igor PDML-StR wrote: > > > > > > I've discovered that NiMH AA batteries that were in the old Pentax DS body > > (remember those?) were completely dead. > > I tried to put them in renown La Crosse charger (BC-900), and that refused > > to charge them. > > > > I was able to resuscitate them by putting them into a "fast" Duracell > > charger, and then trying to start charging a few times by plugging that > > charger into the power outlet. At first, that charger also refused to charge > > them, but after 3-4 attempts, the first pair started charging, and then > > (after that pair was somewhat charged, so that I can put them in BC-900), I > > did 2-3 more attempts with the second pair, and it worked. > > > > I suspect BC-900 was a bit too gentle with the initial charge attempt. > > But it is also possible that it could have worked if I tried a few more > > times. > > > > I am not sure how well these batteries will work, the time will show. > > But at least this allowed to charge them up. > > > > An alternative would be to use a 1.5 V power supply, but this trick was > > simple enough. > > > > I thought this might be useful to somebody. > > > > > > Igor > > > > > > -- > > PDML Pentax-Discuss Mail List > > PDML@pdml.net > > http://pdml.net/mailman/listinfo/pdml_pdml.net > > to UNSUBSCRIBE from the PDML, please visit the link directly above and > > follow the directions. > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Re: Hint on reviving old rechargable batteries
Indeed, "intelligent" chargers would detect "bad" batteries and refuse to charge them; and often you can jump-start them in a "dummy" charger. Apparently that's a feature. You could use the BC 900 to test or refresh the batteries (don't leave the charger unsupervised! - nor near flammable materials). I assume the old batteries had no signs of physical damage/leaks/corrosion. Alex On Tue, Dec 19, 2017 at 8:00 PM, Igor PDML-StR wrote: > > > I've discovered that NiMH AA batteries that were in the old Pentax DS body > (remember those?) were completely dead. > I tried to put them in renown La Crosse charger (BC-900), and that refused > to charge them. > > I was able to resuscitate them by putting them into a "fast" Duracell > charger, and then trying to start charging a few times by plugging that > charger into the power outlet. At first, that charger also refused to charge > them, but after 3-4 attempts, the first pair started charging, and then > (after that pair was somewhat charged, so that I can put them in BC-900), I > did 2-3 more attempts with the second pair, and it worked. > > I suspect BC-900 was a bit too gentle with the initial charge attempt. > But it is also possible that it could have worked if I tried a few more > times. > > I am not sure how well these batteries will work, the time will show. > But at least this allowed to charge them up. > > An alternative would be to use a 1.5 V power supply, but this trick was > simple enough. > > I thought this might be useful to somebody. > > > Igor > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
Hint on reviving old rechargable batteries
I've discovered that NiMH AA batteries that were in the old Pentax DS body (remember those?) were completely dead. I tried to put them in renown La Crosse charger (BC-900), and that refused to charge them. I was able to resuscitate them by putting them into a "fast" Duracell charger, and then trying to start charging a few times by plugging that charger into the power outlet. At first, that charger also refused to charge them, but after 3-4 attempts, the first pair started charging, and then (after that pair was somewhat charged, so that I can put them in BC-900), I did 2-3 more attempts with the second pair, and it worked. I suspect BC-900 was a bit too gentle with the initial charge attempt. But it is also possible that it could have worked if I tried a few more times. I am not sure how well these batteries will work, the time will show. But at least this allowed to charge them up. An alternative would be to use a 1.5 V power supply, but this trick was simple enough. I thought this might be useful to somebody. Igor -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
