tag:blogger.com,1999:blog-5854741938955568545.post5837908371448182743..comments2024-03-26T01:53:19.600-07:00Comments on ElectricRCAircraftGuy.com--RC, Arduino, Programming, & Electronics: Restoring/Recharging Over-discharged LiPo (Lithium Polymer) Batteries!Gabriel Stapleshttp://www.blogger.com/profile/10071071884455787806noreply@blogger.comBlogger66125tag:blogger.com,1999:blog-5854741938955568545.post-58592641637970317222023-10-02T16:59:24.596-07:002023-10-02T16:59:24.596-07:00Hi Gabriel. Thanks for your blog post about overly...Hi Gabriel. Thanks for your blog post about overly discharged lipos. I just had a small accident on my desk while doing some setup on my drone. I left the 2S 450mah battery attached and it burned down to ~3.0V per cell. My first thought: toss it. My second: Why should I? - Maybe there is some explanation on the internet why and when to toss damaged, discharged lipo packs.<br />So my 2S pack is currently, slowly recovering at the charger after being less that 10 minutes in that deep discharged state. They are doing well. Cold to the touch and slowly regaining energy. Does the time they spend deeply discharged add up to the damage/internal resistance? Or asked the other way around: Is time critical? Since it is chemistry, that will cause the internal resistance that leads to temperature build up, I am curious if time is critical.Larshttps://www.blogger.com/profile/01699622582014237330noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-31021181307962169922023-08-28T04:39:14.779-07:002023-08-28T04:39:14.779-07:00Hi ,sir I have a question about 2S lipo battery ,h...Hi ,sir I have a question about 2S lipo battery ,how long will a 2S lipo battery which is powering an esp32 and 4 1000 kv bldc motors (for a drone) last? Because as I was testing my drone motors for merely 30 minutes and powering the motors one by one and then powering all of them together for hardly 6 sec the motors stopped working and when I checked the voltages, the total voltage was 4 V while one of the cell was unbalancedly discharged to 0.96 V .Intitially both of them were at nearly 3.7 v(3.71 nad 3.73 V respectively) .And also is it possible to balance them again?Shubhhttps://www.blogger.com/profile/12237148402012636164noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-46184487292897374602022-02-01T02:26:50.009-08:002022-02-01T02:26:50.009-08:00Hello, thank you for your blog. Consider that any ...Hello, thank you for your blog. Consider that any battery can catch fire if discharged at a high rate (not only on charge, as example due a shorcircuit or due electric motor stalled). The energy dissipated in the internal resistance can heat it in the same amount in charging or discharging at the same rate. The dissipated power is I^2*R where R is the internal resistance, if the dissipation resistance temperature increases the battery over 60ºC, the battery catch fire. Best regards, JavierJavierhttps://www.blogger.com/profile/03648043912612436932noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-51598070807547726622021-09-09T14:55:42.616-07:002021-09-09T14:55:42.616-07:00Greetings Gabriel,
Two months later and I can'...Greetings Gabriel,<br /><br />Two months later and I can't tell any difference between this battery and the one that DID NOT spend the night in a tree. Thanks again for posting this. I've picked up our club newsletter duties and think I'll write a very short story and include a link to this page.<br /><br />If you don't mind, I may have to browse your pages for other great tips to share in the newsletter.<br /><br />Respectfully,<br /><br />JohnJohnThttps://www.blogger.com/profile/02898675925429579078noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-81808796906255200842021-07-01T10:49:56.509-07:002021-07-01T10:49:56.509-07:00JohnT, hey, thanks for sharing your experience! Le...JohnT, hey, thanks for sharing your experience! Let me know how well the battery works once you get it recovered and back in-use. The battery you see at the top of this article, overdischarged on 12/17/2012, I just flew yesterday (30 June 2021) on one of my 3D combat airplanes. It still flies ok, all this time later, despite being discharged to ~1.0V/cell those 8.5 yrs. ago or so. It has **definitely** had a noticeable decrease in power since that day, but it still works today, nonetheless. <br /><br />The secret to battery long life is to **store your batteries in the fridge**, always, to increase their longevity. This prevents natural capacity decay/battery health decay which otherwise occurs over time and is exacerbated by the batteries being stored full (which I frequently do anyways, so they can be ready-to-go), or at warm temperatures. Hot temperatures are especially bad for the batteries. By storing them in the fridge, always, I at least double if not quadruple their lifespan. Again, that overdischarged battery from 2012 still works today in 2021, and still has enough power to hover my 3D airplane and accelerate it vertically, just not as well as the other one like it (also from 2012), which I never overdischarged nor got stuck in a tree.Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-77780342517586372612021-06-30T13:23:53.587-07:002021-06-30T13:23:53.587-07:00Gabriel, "get your plane stuck overnight in a...Gabriel, "get your plane stuck overnight in a tree".<br /><br />This is just the thing that brought me here. After spending the night 55 feet up a Pin Oak, getting knocked about by some guy that climbed the tree with pool cleaning poles taped together and finally being rescued, the LiPo in my Volantex Phoenix was reading: 0.92V | 1.01v | 0.98V.<br /><br />My first thought was, "Toast". Next thought was GTS! (Google That Sh!t!). Found your page and am slowly recovering my battery. Had to charge the 1800mAh nano-tech at 0.01A on the NiMh setting. After about 30 minutes, battery is just over 3V/cell and I'm back on the LiPo setting following Step 2.<br /><br />From one tree parker to another, THANKS!<br /><br />John<br /><br />JohnThttps://www.blogger.com/profile/02898675925429579078noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-62069305709512611352020-09-18T04:10:41.165-07:002020-09-18T04:10:41.165-07:00Hello,
I had two lithium polymer batteries of 11.1...Hello,<br />I had two lithium polymer batteries of 11.1 V and 14.8 V and both are of 25C. The voltage on when checked by multimeter was 11.48 V and 15.07 V respectively. Now I want to discharge those batteries using resistors. I was doing calculations to find the resistor values. Can any one help me in calculating the resistor values.Kranthi Kumar Reddyhttps://www.blogger.com/profile/11780800447566008399noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-20947813238998159752020-07-01T13:00:50.097-07:002020-07-01T13:00:50.097-07:00Hi Gabriel, thank you for your reply. Testing the ...Hi Gabriel, thank you for your reply. Testing the cells individually all cells in the 2 batteries had more than 3V. As the chances for a broken charger were quite high I have purchased a new one. And indeed it was the charger that was not working properly anymore. Any chance one can fix it?Nr2.aboonhttps://www.blogger.com/profile/01148341309126329170noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-23215553844136869952020-06-08T01:38:56.983-07:002020-06-08T01:38:56.983-07:00Note: in the 2S LiPo case of 4.2V in one cell and ...Note: in the 2S LiPo case of 4.2V in one cell and 2.61V in the other, if the charger refuses to charge in LiPo mode it would be because the one cell is too low. It may detect that it is < 3.0V in that one cell and refuse to charge. Please report back your findings. I'm anxious to see what you figure out. Thanks!Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-46345779288449714652020-06-08T01:37:11.555-07:002020-06-08T01:37:11.555-07:00Not sure. What makes you think they both have >...Not sure. What makes you think they both have > 3V/cell? I suspect they actually *don't*. A 2S LiPo at 6.81V, for instance, could have 1 full cell at 4.2V and the other cell at 6.81V - 4.2V = 2.61V. If this is the case, the charger may refuse to charge it in LiPo mode and you may start yourself a fire in NiCd mode. <b>Check each cell individually and please report back to me.</b><br /><br />Also, most likely, if you can read the voltage for each cell on the balance plug, and for the whole pack on the main lead, chances are the battery wiring is OK and it's the charger, although an intermittent open circuit due to a broken wire inside the battery pack is always a possibility. A normal multimeter can be used to read the voltage. Reading individual cell voltage is just a matter of reading 2 wires on the balance lead next to each other. Each pair of 2 is a cell. Move down the line 1 wire at a time to measure the next cell. Just be very careful NOT to short the leads while reading manually if you use a multimeter.Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-5001086217352756282020-06-01T04:40:07.982-07:002020-06-01T04:40:07.982-07:00Hi Gabrial, thank you for this.
I have a question....Hi Gabrial, thank you for this.<br />I have a question. I have 2 batteries (2s) that wont charge anymore. Both of them have more than 3v per cell. One having around 6.2, the other having 6.81. Normal LiPo charging does not change the voltage, I have also tried to charge with the NiCd method but the voltage does not change and remains at 6.2 for example, charging only around 2 mintues and then stopping the charge automatically. Could it be that the charger is not working properly or the batteries?<br />Thank you, JanNr2.aboonhttps://www.blogger.com/profile/01148341309126329170noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-23295343303276847352020-05-14T09:04:04.784-07:002020-05-14T09:04:04.784-07:00end results: 1874mah 12.59v 69minutes avearge of 7...end results: 1874mah 12.59v 69minutes avearge of 7mA charge rateAnonymoushttps://www.blogger.com/profile/13360834277373027552noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-40620267876382199742020-05-14T08:01:54.614-07:002020-05-14T08:01:54.614-07:00Worked almost instantly on a TP 1800 30c which was...Worked almost instantly on a TP 1800 30c which was on average 1.2v/cell from being left plugged in for months on end and just discovered. Set the Triton for NiMh @ .1a and watched until the voltage was just over 9v. Literally took less than 5 minutes, then switched to LiPo bal/1800 11.1v NOTE:Keep an eye on the voltage!! It happened very quickly!! Will report the charge info when completed.Anonymoushttps://www.blogger.com/profile/13360834277373027552noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-74399055467464406422019-12-23T22:03:34.189-08:002019-12-23T22:03:34.189-08:00I used a 5v 2.0 amp power supply and brought back ...I used a 5v 2.0 amp power supply and brought back 6 3.7s that were down to 1.3volts each. I had a couple that were below 1v and after charged the voltage fell like you described. These also got warm while charging, while the "restored" batteries never heated up. Seems like they would give a fair warning before a meltdown but i still charged in a metal cash box with a timer just in caseprerunninghttps://www.blogger.com/profile/08141220640908158152noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-71700368078392060982019-09-22T21:49:10.679-07:002019-09-22T21:49:10.679-07:00@XAirCdt, as I explain in the article, use the NiM...@XAirCdt, as I explain in the article, use the NiMh setting temporarily:<br /><br />"Additional Charge Setting Notes: recharging a LiPo below 3.0V/cell may require using a NiMh or NiCad charger setting on the LiPo batteries, as most smart chargers have safety features which prevent a user from attempting to charge a LiPo which is below 2.5V/cell, as this can be dangerous if a standard charge rate is used. Since all we are after is setting a low (and safe) constant charge current to get the LiPo back up to a safe charge level, using a NiMH/NiCad setting is fine until we get the battery >3.0V/cell. WHEN USING AN NIMH or NiCad SETTING TO GET THE LIPOS ABOVE 3.0V/CELL, ***NEVER*** LEAVE THEM UNATTENDED. You should not leave them unattended because the NiMh/NiCad end-of-charge detection method is not compatible with Lithium based batteries, and if left on the charger until full, the end-of-charge state will never be detected and the LiPo battery will be overcharged until it (likely) catches fire and destroys itself (see the burning LiPo picture above; you don't want that to happen)."Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-12151742056320118752019-09-22T08:53:53.758-07:002019-09-22T08:53:53.758-07:00How do I bypass the Turnigy Accucel and its batter...How do I bypass the Turnigy Accucel and its battery check.. just says "low voltage" and doesn't let me startXAirCdthttps://www.blogger.com/profile/04305738987708038118noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-21551194521562692852019-07-07T14:22:12.661-07:002019-07-07T14:22:12.661-07:00@Gabriel and all readers. Alot of useful informati...@Gabriel and all readers. Alot of useful information Gabriel. Like you im not at all a "by the book" type person and if it was up to me would of took my chances and kept my Samsung Note 8 phone everyone was so scared of because a handful out of millions caught fire..<br /> However people should know when a fairly large Lipo does "explode",it can be quite dangerous. Yes its not like a 1/4 stick of dynamite and a quick boom. <br /> The best way i can describe the "explosion" that happened to me with a fully charged 7.2 volt 30-40C burst 4000mha brick shaped R/C type battery. Would be initially a burst of super hot flame and smoke shooting from the work bench in my garage almost to the ceiling. Luckily the overhead door was open and i was only 5-6 feet from the door. I was able to pull it off the bench with the the claw of a hammer that was right there, then managed to kick it out of the garage into my driveway. After the initial blast it turned into a continuous flame that id best describe as the flame coming off of a road flare except going from Much larger initially then alittle smaller until all the gases had depleted.<br /> I don't think you've personally experienced how bad they can possibly be and your advice kinda makes light of it in my opinion. <br /> Firstly you said something along the lines of you prefer holding the battery with a flame proof bag nearby in case you need to put it in it. If it explodes your not going to be holding it anymore, its going to immediately fall from your hand and ignite anything it combustible.. <br /> Secondly someone asked about "depuffing a battery ?" You were absolutely correct with saying the internal gases will probably be ruined if they come in contact with oxygen.<br /> EXCEPT, they will be more the ruined.. Several years ago before i properly educated myself on Lipo batterys. Thats exactly what caused my explosion. I stupidly attempted to "debloat" the battery. It looked to me like there was just air trapped in the heat shrink causing it to be swollen. So i tried to just put a pin hole in the heat shrink thinking it just needed to breath.<br /> NOT.. Ive read since that Lipo batteries are intentionally sealed because the gases will immediately ignite if they come in contact with air or water. So i don't know this for a fact but that makes it sound like water wouldn't even help in the case of a Lipo battery burning. I don't know if it would be as bad as trying to put an oil fire out with water, but I know from experience that flame was so intense I don't think anything would put it out until it's done doing its thing.. Seemed like forever when it happened to me, was probably about 30-40 seconds. Id imagine a cell phone size battery would be at the most like 10 seconds.. <br /> So anyways unless you have a store bought Lipo charging container. Especially if your messing around and breaking the Lipo "rules". I suggest not having anything combustible close by and placing the battery in something metal. Grab a kitchen pot with a lid if you have to. Then you can put the lid on contain it and carry it outside if you have too. (Actually just thought of that.)<br /> Thank god i happened to make this stupid decision in my garage rather then my basement where I normally worked/charged batteries. Best case scenario I would have had a small fire. But if I happen to like have it in my hand and panicked and tossed it and it landed on a bunch of boxes and crap it could of been life changing.<br /> Thanks and Good Luck.Kenhttps://www.blogger.com/profile/01586706403747562684noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-14215248675745124092019-07-07T14:21:39.734-07:002019-07-07T14:21:39.734-07:00@Gabriel and all readers. Alot of useful informati...@Gabriel and all readers. Alot of useful information Gabriel. Like you im not at all a "by the book" type person and if it was up to me would of took my chances and kept my Samsung Note 8 phone everyone was so scared of because a handful out of millions caught fire..<br /> However people should know when a fairly large Lipo does "explode",it can be quite dangerous. Yes its not like a 1/4 stick of dynamite and a quick boom. <br /> The best way i can describe the "explosion" that happened to me with a fully charged 7.2 volt 30-40C burst 4000mha brick shaped R/C type battery. Would be initially a burst of super hot flame and smoke shooting from the work bench in my garage almost to the ceiling. Luckily the overhead door was open and i was only 5-6 feet from the door. I was able to pull it off the bench with the the claw of a hammer that was right there, then managed to kick it out of the garage into my driveway. After the initial blast it turned into a continuous flame that id best describe as the flame coming off of a road flare except going from Much larger initially then alittle smaller until all the gases had depleted.<br /> I don't think you've personally experienced how bad they can possibly be and your advice kinda makes light of it in my opinion. <br /> Firstly you said something along the lines of you prefer holding the battery with a flame proof bag nearby in case you need to put it in it. If it explodes your not going to be holding it anymore, its going to immediately fall from your hand and ignite anything it combustible.. <br /> Secondly someone asked about "depuffing a battery ?" You were absolutely correct with saying the internal gases will probably be ruined if they come in contact with oxygen.<br /> EXCEPT, they will be more the ruined.. Several years ago before i properly educated myself on Lipo batterys. Thats exactly what caused my explosion. I stupidly attempted to "debloat" the battery. It looked to me like there was just air trapped in the heat shrink causing it to be swollen. So i tried to just put a pin hole in the heat shrink thinking it just needed to breath.<br /> NOT.. Ive read since that Lipo batteries are intentionally sealed because the gases will immediately ignite if they come in contact with air or water. So i don't know this for a fact but that makes it sound like water wouldn't even help in the case of a Lipo battery burning. I don't know if it would be as bad as trying to put an oil fire out with water, but I know from experience that flame was so intense I don't think anything would put it out until it's done doing its thing.. Seemed like forever when it happened to me, was probably about 30-40 seconds. Id imagine a cell phone size battery would be at the most like 10 seconds.. <br /> So anyways unless you have a store bought Lipo charging container. Especially if your messing around and breaking the Lipo "rules". I suggest not having anything combustible close by and placing the battery in something metal. Grab a kitchen pot with a lid if you have to. Then you can put the lid on contain it and carry it outside if you have too. (Actually just thought of that.)<br /> Thank god i happened to make this stupid decision in my garage rather then my basement where I normally worked/charged batteries. Best case scenario I would have had a small fire. But if I happen to like have it in my hand and panicked and tossed it and it landed on a bunch of boxes and crap it could of been life changing.<br /> Thanks and Good Luck.Kenhttps://www.blogger.com/profile/01586706403747562684noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-77848244981172643122019-05-20T12:53:29.507-07:002019-05-20T12:53:29.507-07:00@MikeThePipe, thanks for the info! I appreciate th...@MikeThePipe, thanks for the info! I appreciate the tip. I googled for the "B3603" buck converter and it looks like a nice little economical DC-DC step-down converter to help with our specialty power supply and charging needs, as you've said. I may end up purchasing one sometime. Thanks again!Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-67539065254534884522019-05-19T02:46:39.881-07:002019-05-19T02:46:39.881-07:00Hi. Thanks for a great article on LiPo recovery. I...Hi. Thanks for a great article on LiPo recovery. I'm just trying to recover a 2200mAh 3s that's down at 3.4v total.<br />Main reason for my comment is to introduce you to a great constant current/voltage device I use a lot, the B3603 a DC-DC step down (user manual here: <a href="URL" rel="nofollow">https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwiM77L1pafiAhW7UBUIHWu1A-oQFjAAegQIARAC&url=https%3A%2F%2Fwww.elecrow.com%2Fdownload%2FB3603%2520User%2520Manual.pdf&usg=AOvVaw1cjA4qF6fnUHf-plstbCXd</a>). It has complete control over output volts and current. Ideal for 'bespoke' charging needs. One WARNING: Always set & check outputs before connecting device - it has a bad habit of powering-on to previous state.MikeThePipehttps://www.blogger.com/profile/01874076135856569935noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-52111425403688326832019-02-05T23:34:42.017-08:002019-02-05T23:34:42.017-08:00Hi, taking a guess that the tiny LiPo cells from p...Hi, taking a guess that the tiny LiPo cells from picture frames are probably trash now. Some of them are over 6 years old and though charged at the factory are most likely bricked, attempted to restore them but they are usually hopeless.<br />I did get one working from an E-cig though and the slightly older "metal" case ones seem more robust.<br />Anonymoushttps://www.blogger.com/profile/04413052252957228654noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-89968514777543409672018-10-04T13:48:31.335-07:002018-10-04T13:48:31.335-07:00Thanks Gabriel for the info. Th bad news 3 of the ...Thanks Gabriel for the info. Th bad news 3 of the 4 cells are short and I was not able to regenerate, but 1 cell from the middle of the battery was recovered and charged fully.<br />Luckily I had a same tipy of 4S battery where only ne cell damaged in crash.<br />I made a 4s using the recovered cell and teh 3 remaining from that battery and it flies perfect, no voltage drop.<br />It took for a while as the batttery leads were mmade of aluminium or spacial steel and I had to order special flux from Russa to be able to solder aluminium, but now it is done :)<br />At leaset I could recover 1 cell and fix my other batery using that.<br />The other 3 cell cannot take charge, if I put them on 80mA for a day theri internal material becomes soft like a gel.. very strange but no heat....Foto Amghttps://www.blogger.com/profile/12641610895665499843noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-69149274736524831782018-09-11T19:02:06.258-07:002018-09-11T19:02:06.258-07:00That looks like a pretty good link you shared.
I ...That looks like a <a href="https://lygte-info.dk/review/Review%20Charger%20TP4056%20UK.html" rel="nofollow">pretty good link you shared</a>.<br /><br />I don't think I've ever recovered and been able to use a cell that was less than 1.0V or so (maybe 0.5~1.0V?), so I think you're out of luck: buy a new battery. There is too much permanent damage done. I think it has to do with crystal growth from anode to cathode which punctures internal cell walls and internally shorts the battery or something--I'd have to do a lot more research to be able to speak more knowledgeably than that, and to verify my facts. In either case, sorry, but you'll have to buy a new battery.Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-43833202206140291102018-09-11T15:14:46.881-07:002018-09-11T15:14:46.881-07:00Hi!
I have a smaller board TP4056 charger which ca...Hi!<br />I have a smaller board TP4056 charger which can regenerate cells.<br />https://lygte-info.dk/review/Review%20Charger%20TP4056%20UK.html<br />I use it on the balance plug and regenerate cells one by one.<br />If the cell voltage is below 2.85 volt the charger will charge with about 80mA max, but now I am facing a big challenge. My drone lost and I found it 46day later battery was plugged in for 46days and it was at zero voltage for more thena month :( the battery is brand new I only used it once before Infinity Graphene 70C 1500mAh and did not get any hit or deformation in the crash and not puffy so no signs of externel damage.<br />I put fist cell to that regenarator ahd waited now 4 hours, no heating at all, but voltage is still at 0.6V :( no way to get them back?Foto Amghttps://www.blogger.com/profile/12641610895665499843noreply@blogger.comtag:blogger.com,1999:blog-5854741938955568545.post-56463724681173875132018-02-24T14:53:08.588-08:002018-02-24T14:53:08.588-08:00Thanks for the comment! It looks like they can be ...Thanks for the comment! It looks like they can be purchased for < $1 a piece too when you buy a pack of them on Amazon! See here: <a href="https://www.amazon.com/s/ref=as_li_ss_tl?url=search-alias=aps&field-keywords=tp4056&linkCode=ll2&tag=wwwel-20&linkId=e043f044fc386e7f1b2a095144b8bc9c" rel="nofollow">Amazon search for "TP4056"</a>Gabriel Stapleshttps://www.blogger.com/profile/10071071884455787806noreply@blogger.com