Richard Wills 2 Posted July 10, 2020 Share Posted July 10, 2020 If you have had 2 cells overcharges to that degree you are very lucky to not have had a fire. GET IT OUT OF YOUR HOUSE NOW. Then discharge it to zero volts and bin it, the battery is dangerous and faulty and cannot be shipped with any carrier. Quote Link to comment Share on other sites More sharing options...
David Ramsden Posted July 10, 2020 Author Share Posted July 10, 2020 No Bob, the cells were definitely reading 5.26v, 5.65v, and 0.41v. I abandoned the balance charge at 12.3v and I'm just about to put the battery outside the house for safety. The cells are now reading 6.9, 7.3, and 6.8 (but the balance charge had not quite finished). I will ask Wireless-Madness for another one. Thanks all. David Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted July 10, 2020 Share Posted July 10, 2020 If your cells are reading over 4.2v you have overcharged the pack and are inline for a fire. There have been a few fires caused by Lipos, one burning his garage down. Stop messing with the pack, discharge it and buy a new one, before someone gets hurt or worse... Edited By Paul Marsh on 10/07/2020 14:41:44 Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted July 10, 2020 Share Posted July 10, 2020 David If you have put the battery on charge, as distinct from trying to charge it, I seriously doubt you will get any recompense from a supplier. Most state in the small print that any sort of 'use', charge or discharge, negates their warranty. I presume your charger can display the individual cell voltages during the balance charge. It is good practise to monitor them during charging. It will be very evident if one cell is 'weak' as it will reach 4.2 V whilst the good cells are still charging at less than 4 V. With a 'good' LiPo the cell voltages should not vary by more than 0.02 V during the entire charge process. The opposite will happen if you try to use it. The weak cell will drop voltage (and become exhausted) much more quickly than the good ones. Once the weak cell is below 3 V it will be damaged further and is likely swell up. This situation will get worse each time you try to use it and could quickly lead to serious trouble. A 'weak cell' LiPO is potentially dangerous, hence the advice to safely discharge it fully and bin it. Quote Link to comment Share on other sites More sharing options...
Dickw Posted July 10, 2020 Share Posted July 10, 2020 Posted by David Ramsden on 10/07/2020 14:20:30: No Bob, the cells were definitely reading 5.26v, 5.65v, and 0.41v. I abandoned the balance charge at 12.3v and I'm just about to put the battery outside the house for safety. The cells are now reading 6.9, 7.3, and 6.8 (but the balance charge had not quite finished). I will ask Wireless-Madness for another one. Thanks all. David 6.9 + 7.3 + 6.8 = 21 volts, and yet you say you abandoned the balance charge at 12.3 volts! Something very odd there. Definitely leave that battery somewhere safe outside, and do watch carefully next time you use the charger - just in case. Dick Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted July 10, 2020 Share Posted July 10, 2020 I suspect that a LiPo cell at over 6v would at the very least look like a balloon. If those voltages were displayed on your charger then the charger needs binning as well as the battery. Any working charger should have cut off the individual cell charge at 4.2v, if they were over that when plugging the battery in then the charger should have complained of over-voltage. Something is very wrong! Are you sure that you have selected a 3 cell balance charge? Quote Link to comment Share on other sites More sharing options...
Richard Clark 2 Posted July 10, 2020 Share Posted July 10, 2020 Posted by EarlyBird on 10/07/2020 13:01:59: David For me that is very bad advice from Adam at Wireless-Madness because all the readings indicate it is a faulty battery and therefore dangerous to use. I would follow the advice given by Nigel R. What has Adam gained by his bad advice? Saved having to refund you? Totally compromised Wireless-Madness's good name? He's certainly lost me as a potential customer. All in an attempt to avoid giving David his money back. Quote Link to comment Share on other sites More sharing options...
Keith Miles 2 Posted July 10, 2020 Share Posted July 10, 2020 Agree with others. NEVER take chances with any LiPo! Cells should be balance charged and kept in balance for a reason and once any cell has dropped below 3 volts it is likely to have already suffered damage and should be discarded. Furthermore a Lipo cell should NEVER be charged above 4.2 volts and any significant voltage differences between cells is also something to be very wary of. And NEVER use any setting on a charger other than the correct setting for the battery type and cell count/voltage! A good battery and charger and correct use of both will avoid potential dangers! I would also suggest that you get yourself a battery checker. Plenty of choice. Pocket sized and more convenient to use than a multimeter. If you want to see what can happen when you mistreat a Lipo, you will find a number of clips on YouTube! P.S. Oh, I see someone has since posted such a clip and having watched it, and despite claims, in the clip, that the victim is a “professional”, human error cannot be ruled out especially as this was, apparently, his second such experience! My view is that if Lipos are inherently dangerous and unpredictable they would not be on sale! Edited By Keith Miles 2 on 10/07/2020 15:25:53 Edited By Keith Miles 2 on 10/07/2020 15:47:28 Quote Link to comment Share on other sites More sharing options...
Richard Clark 2 Posted July 10, 2020 Share Posted July 10, 2020 Posted by Keith Miles 2 on 10/07/2020 15:22:31: Agree with others. NEVER take chances with any LiPo! Cells should be balance charged and kept in balance for a reason and once any cell has dropped below 3 volts it is likely to have already suffered damage and should be discarded. Furthermore a Lipo cell should NEVER be charged above 4.2 volts and any significant voltage differences between cells is also something to be very wary of. And NEVER use any setting on a charger other than the correct setting for the battery type and cell count/voltage! A good battery and charger and correct use of both will avoid potential dangers! I would also suggest that you get yourself a battery checker. Plenty of choice. Pocket sized and more convenient to use than a multimeter. If you want to see what can happen when you mistreat a Lipo, you will find a number of clips on YouTube! P.S. Oh, I see someone has since posted such a clip! Edited By Keith Miles 2 on 10/07/2020 15:25:53 Not only did he do it twice, he didn't put a door on his 'fireproof' cabinet. Dumb or what? Quote Link to comment Share on other sites More sharing options...
Keith Miles 2 Posted July 10, 2020 Share Posted July 10, 2020 Posted by Keith Miles 2 on 10/07/2020 15:22:31: If you want to see what can happen when you mistreat a Lipo, you will find a number of clips on YouTube! P.S. Oh, I see someone has since posted such a clip! Not only did he do it twice, he didn't put a door on his 'fireproof' cabinet. Dumb or what? Richard Clark, yes, indeed! And I had edited my post before seeing your reply. There are “professionals” and “enthusiastic amateurs” and some of the latter might claim to be the former! Edited By Keith Miles 2 on 10/07/2020 15:57:08 Quote Link to comment Share on other sites More sharing options...
David Ramsden Posted July 10, 2020 Author Share Posted July 10, 2020 The battery in question is outdoors and Wireless-Madness have asked me to "Open a Returns Case" on Ebay. They will arrange for Hermes to collect it from me. Dee from Wireless-Madness just told me on the phone that people on forums are often over cautious with regard to Lipos and that packs with a low voltage cell can usually be recovered and thereafter work fine. He said between 1 in 100 and 1 in 1000 overlander batteries are like this and once recovered (by the process they talked me through) are fine. That advice seems directly contrary to all the advice I've received on this forum. As a complete novice, it is baffling to be confronted with this situation with my very first battery and charger. I am sending the battery back but obviously I still want one! Who would you go to for a good overlander 2900mah 3s by mail order? Quote Link to comment Share on other sites More sharing options...
Richard Clark 2 Posted July 10, 2020 Share Posted July 10, 2020 Posted by David Ramsden on 10/07/2020 16:16:25: The battery in question is outdoors and Wireless-Madness have asked me to "Open a Returns Case" on Ebay. They will arrange for Hermes to collect it from me. Dee from Wireless-Madness just told me on the phone that people on forums are often over cautious with regard to Lipos and that packs with a low voltage cell can usually be recovered and thereafter work fine. He said between 1 in 100 and 1 in 1000 overlander batteries are like this and once recovered (by the process they talked me through) are fine. That advice seems directly contrary to all the advice I've received on this forum. As a complete novice, it is baffling to be confronted with this situation with my very first battery and charger. I am sending the battery back but obviously I still want one! Who would you go to for a good overlander 2900mah 3s by mail order? Go to? Overlander itself. Their online service is quick, they have more of their own brand batteries in stock than anyone else (obviously), and they actually test the individual cells and 'assemble' the pack themselves (I don't think anyone in the UK actually manufactures the individual cells). So they do have a clue, unlike some unknown bloke on Ebay who will probably be selling garden buckets or naff jewellery next week, or even some model shops. Much of their business is ' industrial' so they are are a fairly big and well known business with a reputation to protect. If you should need to call them their guys are competent too. Why waste time on 'middlemen', well known or not? And why 'recover' a new battery? You shouldn't have to do that whatever he says. Edited By Richard Clark 2 on 10/07/2020 16:54:09 Edited By Richard Clark 2 on 10/07/2020 16:55:06 Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted July 10, 2020 Share Posted July 10, 2020 David It looks like Wireless-Madness are going to continue dishing out bad advice and defending themselves by accusing us of being over cautious. I wonder if they will sell the battery to someone else and if you are not the first to be sold it. Judging by the high voltage readings on the two cells it could have been charged by someone who did not know what they were doing. When I started and knew nothing I received a new 5000mah 3s lipo with exactly the same issue in that it would not charge. As you have done I checked the cell voltages and one was down to 1.5 volts. I contacted the supplier received an apology and a store credit. As for the lipo they told me do not send it back but dispose of it myself. I buy all of my lipos and much more from them simply because in my mind their response to my problem was excellent. Anyway well done and I for one can stop worrying about you burning your house down by listening to all the over cautious advice. Overlander are here. Lipo 2900 Steve Edited By EarlyBird on 10/07/2020 17:01:37 Edited By EarlyBird on 10/07/2020 17:05:38 Edited By EarlyBird on 10/07/2020 17:06:52 Quote Link to comment Share on other sites More sharing options...
Richard Wills 2 Posted July 10, 2020 Share Posted July 10, 2020 Listening to the advice that you have got, and the fact that they want to go against the carrier terms and conditions and transport a potentially dangerous pack putting more people at risk, I doubt i'll be darkening their door to make an order in the future. Quote Link to comment Share on other sites More sharing options...
Keith Miles 2 Posted July 10, 2020 Share Posted July 10, 2020 Posted by David Ramsden on 10/07/2020 16:16:25: The battery in question is outdoors and Wireless-Madness have asked me to "Open a Returns Case" on Ebay. They will arrange for Hermes to collect it from me. Dee from Wireless-Madness just told me on the phone that people on forums are often over cautious with regard to Lipos and that packs with a low voltage cell can usually be recovered and thereafter work fine. He said between 1 in 100 and 1 in 1000 overlander batteries are like this and once recovered (by the process they talked me through) are fine. That advice seems directly contrary to all the advice I've received on this forum. As a complete novice, it is baffling to be confronted with this situation with my very first battery and charger. I am sending the battery back but obviously I still want one! Who would you go to for a good overlander 2900mah 3s by mail order? Firstly, if you what you say is true, I would get a refund and never again seek advice from Dee or Adam or, perhaps, anyone else who works for Wireless Madness! Perhaps they are aptly named? ”Over cautious”? No. Scientific fact that when a Lipo cell discharges to 3v or less, the internal chemistry deteriorates. This is also the case with batteries in general but Lipos require particular care as the chemistry is more volatile. This is widely understood within the model flying community and I am baffled that a company would embarrass itself and potentially damage its business by providing such poor, and potentially dangerous advice, especially to a beginner! Then again, they might not have tried it with an experienced flyer! If you remain unsure, there is plenty of information on line about Lipos and not necessarily associated with any retail business! It is a common mantra that Lipos require a Lipo dedicated charger. Period. Multi-chargers are set up to suit specific individual chemistries and have inbuilt safety features for each individual battery type. Charging a battery, or attempting to, with a charger/battery mismatch is not only misusing both battery and charger but could be dangerous in addition to invalidating the warranties of both! Do you have to have an Overlander 2900? If so, or you just want to keep things simple for now, you can order direct from them via their website. In fact, as long established suppliers of batteries, with a pretty good reputation, you could even ask their opinion of the advice that you were given by the aforementioned duo, especially the bit about recovering the occasional low cell (that 1 in 100 or 1000) rather than the alternative of simply returning it to Overlander for a refund or replacement! The choice of possible alternatives to an Overlander 2900 might be a little baffling at first, as you probably need to consider similar dimensions and C ratings, for starters and, as in all things, whilst expensive might not mean best, cheap might not be good either and, again, opinions can vary about various makes! Welcome to the jungle! Edited By Keith Miles 2 on 10/07/2020 17:43:07 Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted July 10, 2020 Share Posted July 10, 2020 David Earlier you said your charger worked ok charging another 3 cell LiPo. Did you notice the cell voltages during that charge, were they at more or less equal and did they all show 4.2 V at the end? If it showed sensible voltages during and at the end of that charge then clearly the charger is ok and it is the Overlander battery that is at fault in some way. Bad luck that you are having problems with a brand new battery but it can happen just not very often. I would certainly expect your next 100 batteries all to work perfectly! Quote Link to comment Share on other sites More sharing options...
David Ramsden Posted July 10, 2020 Author Share Posted July 10, 2020 Thanks everyone. Simon - I might be wrong but I don't think my charger displays the individual voltages of each cell during and at the end of charge (bear in mind this is my first time using any Lipo charger). It did though show the pack voltage during charge which I monitored. I have just ordered one directly from Overlander. To be fair to Wireless-Madness, they did sound reasonable on the phone and they've not hesitated in recommending a refund. On balance though (and being a cautious sort of chap), I'm not impressed with their advice. The amount of experience amongst forum members must be immense and you are all kind enough to give free advice (which I have followed on this and other questions). Thank you all very much indeed. Quote Link to comment Share on other sites More sharing options...
Keith Miles 2 Posted July 10, 2020 Share Posted July 10, 2020 Posted by David Ramsden on 10/07/2020 19:34:05: Thanks everyone. Simon - I might be wrong but I don't think my charger displays the individual voltages of each cell during and at the end of charge (bear in mind this is my first time using any Lipo charger). It did though show the pack voltage during charge which I monitored. I have just ordered one directly from Overlander. To be fair to Wireless-Madness, they did sound reasonable on the phone and they've not hesitated in recommending a refund. On balance though (and being a cautious sort of chap), I'm not impressed with their advice. The amount of experience amongst forum members must be immense and you are all kind enough to give free advice (which I have followed on this and other questions). Thank you all very much indeed. That’s what we’re here for, well, mostly! Many things might be, or are, debatable but battery characteristics are established science and if you deviate from official instructions regarding their use you put yourself into experimental territory even if you have expertise and know what you are doing! If you have no individual cell check facility on your charger, or even if you do, I can only again highly recommend a battery checker. They are not expensive but very useful for quickly and easily checking your batteries. And on that point, though some will disagree, be particularly wary of Far Eastern suppliers (of anything!) on E-bay and, preferably, buy from a reputable model shop or supplier who will provide you with a genuine article, not a clone, and a likely more reliable and professional customer service! You can probably add a checker to your Overlander order. Check their website and give them a call. And, no, I don’t work for them! And finally, as well as this forum, there is plenty of information for beginners online regarding Lipos and electric RC in general which will provide you with a great deal of very useful basic knowledge about the hobby and the components used. Hopefully, you will be in a better position, then, to take a more informed view of advice received and to judge the possible motives that might be influencing it! P.S. Just checked and Overlander still do a decent checker for £14.99. Add a Lipo bag and the optional temperature probe (if you don’t have one) for your charger and you will have all of the basic safety factors pretty much covered! Oh, and DO read all instructions! Edited By Keith Miles 2 on 10/07/2020 20:48:49 Quote Link to comment Share on other sites More sharing options...
Mike Blandford Posted July 10, 2020 Share Posted July 10, 2020 Posted by David Ramsden on 10/07/2020 19:34:05: I might be wrong but I don't think my charger displays the individual voltages of each cell during and at the end of charge Manual pages 16/17, press the INC button while charging to show the individual cell voltages. Mike Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted July 10, 2020 Share Posted July 10, 2020 David, this is what I linked to earlier. A small investment and an invaluable and convenient tool for any leccy flyer. Those voltages sound quite unbelievable (not that I doubt your word I hasten to add). Firstly, because surely the charger would auto-cutoff at 4.2v if 'LiPo' is selected from the charger menu and secondly, Is it chemically possible for a LiPo to reach those voltages irrespective of whether it catches fire or explodes? Could the charger be telling porkies? Quote Link to comment Share on other sites More sharing options...
Michael Kulagin Posted July 10, 2020 Share Posted July 10, 2020 First off I must confess that I have absolutely no experience of electric powered flight but I have been following this topic with a great deal of interest as electric power has been recommended for my latest model. I do, however, have over 35 years experience in aviation Quality Control, much of it in calibration. From the various posts I gather that we are talking about measuring volts to 0.01V and amps to 0.5A, and I feel you'll agree that we are talking about very small measurements. I have also gathered that, in the main, we are all cautious folks and would never knowingly do anything likely to place ourselves and others in a position of danger. Electricity, as it comes out of the socket, is variable. The volts and amps that is put through whatever is plugged in are always nominal values, good enough to run fridges, freezers and tv's etc. The electrical values involved in the charging operation indicates to me that the chargers must be able to control their output to the battery on charge irrespective of the incoming values. First question: are the battery chargers in use manufactured to a recognised standard that guarantees their performance? Second question: Are they calibrated? When they are manufactured it can be assumed that they are 'doing what it says on the box'. Assuming they don't go wrong, they can give good service for a number of years. How can we be sure that they are still performing as designed? Do they ever get checked (calibrated) to ensure that the volts to 0.01V and the 0.5A on the readout are actually what is going in to the battery? Safely charging batteries is reliant on accurate readings so without checking that the equipment in use is up to the job strikes me as being very risky especially as the end result can result in a fire. Quote Link to comment Share on other sites More sharing options...
David Ramsden Posted July 10, 2020 Author Share Posted July 10, 2020 Thanks Keith Mike and Piers. I shall certainly get one of those Piers. Good tip. And great tip Mike about the inc. button while charging. I'll try that. Now the panic is over I shall take more time to get my head around the manual. Such a useful forum! David Quote Link to comment Share on other sites More sharing options...
Richard Ashworth Posted July 10, 2020 Share Posted July 10, 2020 David. Can I echo Piers advice that if you are going electric, get a battery checker. They have dropped a lot in price over the last 5 years and Overlanders checker is not overpriced at £12 for their Backing on service and support. What has not been said (That I have spotted) is the checker gets used on at least 3 occasions in each cycle of a Lipo. First, I always use mine to check its correctLy charged when it comes off the charger after being recharged just before a flying session. At the field you should check the battery is a charged battery and the cells are aligned JUST BEFORE you put it into your model. Well done to anyone who hasn’t accidentally picked up a battery used earlier in a session thinking it was unused. If you are lucky you can feel that the power is down on takeoff and land after a circuit, otherwise you risk discharging the battery to the point where the motor stops on low voltage failsafe and you are doing an unplanned deadstick landing. Lastly checking how much power remains after a successful flight tells you whether you could have flown longer or shouldn’t have flown as long as you drained the battery too much. I don’t know what safety margin others use but I set my tx timer for the plane /battery so that it goes off at about 30% capacity remaining. You then have enough power left for two or three go arounds if needed. Batteries and planes aren’t cheap. The more you look after them the longer they last. Enjoy the hobby. Richard Quote Link to comment Share on other sites More sharing options...
David Ramsden Posted July 11, 2020 Author Share Posted July 11, 2020 Thank you Richard. I have ordered the checker recommended by Piers Bowlan (above) and shall certainly use it as you suggest. With the receiver for this model I also have an extra bit of kit which will eventually give me a voltage reading of the lipo on the transmitter which should help in flight. I've not soldered it into the ESC wires yet. Thought I'd wait until the ESC has proved itself to be the right one. In my reading and watching youtube videos about setting up brushless systems, one thing that nobody seems to talk about is battery duration in flight. Not being part of a club, I have no idea whether a typical flyer takes one two or three charged batteries with them when they go for a few hours flying. I guess no one gives guidance because there are too many variables and generalisations can be misleading. Guess I'll just learn by experience. Hoping to have the maiden flight of my first electric model tomorrow, not with the 2900mah battery as planned(!) but with the 1600mah which charged up fine plus some lead in the nose to make up the weight difference. The rimfire 400 certainly produced an impressive amount of thrust when I tested it in the hanger. Wish me luck! (And thanks again to everyone) Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted July 11, 2020 Share Posted July 11, 2020 David You friend is a Watt meter. It is plugged in between the battery and the ESC. It measures the amps, the volts and calculates the Watts. Most give the peak readings achieved as well. With this information after a short (10 second) full power run you can determine how close the amps are to the limits of the motor, ESC and battery. If you divide the battery capacity (Ah) by the peak current reading it will give the full power duration. It is likely to come out at no more than 1/10 hr (6 minutes). Treat what ever figure you get as a good duration limit for the first few flights. By noting how much you put back into the battery after a flight to reach full charge will give an indication of how much you actually used and thus how much longer you could fly for. It is not uncommon to be able to fly for at least double the full power duration figure with a bit of throttle management. Powered gliders can of course stay up for much longer as they can glide power off for many times the length of the power run. However be warned never fly so that the LiPo is exhausted. You will wreck it. It is good practise not to go below 40% capacity. It takes a bit of trial and error to get to know what duration is acceptable. Quote Link to comment Share on other sites More sharing options...
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