US69 Posted November 19, 2017 Share Posted November 19, 2017 You are right Marty! thats bad news for every!! mTen3 owner! as this Link is definitely designed to weak to stand the currents! For you it’s not that bad news! Try to link the 2 packs together with a much stronger connection! pure fat copper strip should do the job! as you are getting a voltage when connecting ....the cells should all be Ok!!! otherwise the bms would shutdown ...that’s his job! so with a new connection everything should work again! btw: new battery pack is about 400. Dollars....so still much cheaper than a MTen3 :-) but who wants a battery pack designed that bad??? Better work on your existing one... Link to comment Share on other sites More sharing options...
Gimlet Posted November 19, 2017 Share Posted November 19, 2017 37 minutes ago, Hunka Hunka Burning Love said: It's strange though why the nickel strip melted at that exact point. Does it butt up against the plastic shell somehow or was there a pinch or bend in the metal I wonder? Maybe the PCB separator board underneath in close proximity has something to do with it. Hopefully someone at Gotway knows the detailed assembly of the pack and can figure out why it failed at this point. I'm no expert, but I think that particular link is the one that connects the two banks of series linked batteries in parallel so it would be the only nickel link taking full voltage. The connections from the other end of the two banks of batteries are probably the output wires. Link to comment Share on other sites More sharing options...
US69 Posted November 19, 2017 Share Posted November 19, 2017 Some thoughts ot this: This isnt the first time we see something like this happening... Remembering the 680/820wh versions of Msuper? There have been also some photos around here with burned batterypacks and signs of to much stress to the pack. With THIS now, where the complete strip burned away, just has a new quality. Yip, seams the MTen3 has to much power needs for only 20s2p. What i am worried about: Has Gotway done any thoughts about the Tesla? Which operates with 1900/2000Watt, and ONLY on 4 parallel packs (instead of 6 on V3s+ and Acm84v). At least i have a new control section for my regular maintenance! 31 minutes ago, Gimlet said: connections from the other end of the two banks of batteries are probably the output wires. i dont think that the other end goes to output wires...normally the power output wires come from the BMS board. So might be there is a second weak link, which goes to the BMS board... Link to comment Share on other sites More sharing options...
US69 Posted November 19, 2017 Share Posted November 19, 2017 @Jason McNeil Can you inform Gotway about this? .... @Marty Backe I think/hope you will send some of the photos to your seller? Afaik the „green tavelling“ owner also works for/at Gotway, and it will be at least interesting what he says, and if you will get a new pack or so..... Link to comment Share on other sites More sharing options...
meepmeepmayer Posted November 19, 2017 Share Posted November 19, 2017 Quote ...Gotway is not designing this as a system. Definitely indeed! How can they not do ultra-simple, common sense, electricity 101 considerations like "What's the worst this part mighthave to handle?"??? At least with the motor cables they had an excuse (axle space), but what's the excuse for crap like this? Marty, I'd try to get a replacement on Gotway's dime. Otherwise you reward them for making wheels you have to buy twice. Link to comment Share on other sites More sharing options...
eddiemoy Posted November 19, 2017 Share Posted November 19, 2017 Wow! Lucky it didn't fail with you going 20mph over a bump. @Marty Backe, you should get paid by Gotway if you are not already to test their wheels. You seem to find weak points with them. This again points to them not doing proper stress testing on their products before sending out the final product to their user base. I really don't understand what is up with the blind loyalty. If every wheel tried to kill me, I wouldn't buy another wheel from that company who continues to show how badly designed every wheel they release are. I'm still waiting for the bugs to come out on the Tesla. More people need to figure out what will cause the wheel to fail or cut out before I buy one. I refuse to be a human test dummy. LOL Link to comment Share on other sites More sharing options...
Duf Posted November 19, 2017 Share Posted November 19, 2017 Wow this is very disappointing for sure, especially considering the Mten3 I have been waiting a month and a half for just showed up yesterday. Once again Gotway puts their lack of engineering and QC on display..... Seeing this makes me worry about doing anything that could put a high load on the wheel like back and forth reversals which I know you have done a ton of. Did I mention I was disappointed.... Link to comment Share on other sites More sharing options...
gonnabiff Posted November 19, 2017 Share Posted November 19, 2017 5 hours ago, Marty Backe said: Gotway designed and/or provided a battery pack that is not compatible with the power requirements Marty, bless your heart, you continue to be a test pilot and advocate for Gotway, influencing the purchase decisions of newcomers, with personal experience of fail after fail after fail. I understand your attraction to bleeding edge power and bleeding edge range. I don't think you hide your inclination in any way, and your experience in both riding and repairs protects you from harm to some degree. I think that most who do their due diligence and read the material on this site for hours and hours will get the sense that there are alternatives in terms of design, materials and manufacture that offer greater reliability, durability and most likely riding safety. I'd also stress that an exemplary dealer such as Jason at eWheels will discuss a new rider's wants and needs and steer her or him toward choices among the most suitable wheels, and so provide a safe and reliable path to accumulate one's own experience. Please be careful, Marty. You are a valuable asset for the community and I've learned a lot from you. Link to comment Share on other sites More sharing options...
Rehab1 Posted November 19, 2017 Share Posted November 19, 2017 Great work Marty! GW owes you again! The bridge connection could have easily been attenuated during fabrication process of the packs if the strip was stretched thinner during the electronic welding process. Depending on the sequence of the numerous welds that process could have easily heated up the bridged metal strip and stretched it thin. Now the strip would carry less amperage across that site and melt just like a fuse. There would be no reason why you could not solder a 12awg wire across that site and then check the voltage to see if the packs are ok. I am willing to bet the board survived. Good luck buddy. I miss those autopsy days. Link to comment Share on other sites More sharing options...
Chriull Posted November 19, 2017 Share Posted November 19, 2017 Looks like this nickel strip has to take quite some mechanical stress? Is it the only/one of the mechanical fixtures between the two packs? It melted nicely along the edge... From one website i found that a 10mm times 0.13mm nickel strip used to connect cells can carry 15 A. If it has this dimensions thats way too low to connect two banks of two paralleled cells. It would have to withstand the current of two paralleled cells ( ~2*10A nominal) - in combination with mechanical stress it mutates to a heavily underdimensioned fuse. As the nickel strip is also colored at the place it is welded to one of the cells i would not trust this cell anymore - could have easily got quite high temperatures! Edit : seem to be just 2 paralleled cells in total for the mten? So the nickel strip could be ok for nominal burden without mechanical stress, but still not for peak load with some deformation... Edit: would make sense that this nickel strip connects the the two 10s2p packs to a 20s2p pack? Link to comment Share on other sites More sharing options...
US69 Posted November 19, 2017 Share Posted November 19, 2017 43 minutes ago, Chriull said: ooks like this nickel strip has to take quite some mechanical stress? Is it the only/one of the mechanical fixtures between the two packs? Actually the 2 parallel systems are glued together and it cant move a bit at where the strip is... Also the complete pack is secured extra in a big black plastic box. So it seams to be just the current stess, which we have seen on other GW wheels with not that much parallel systems.... I have to say thats really a bummer....its not just a „bit brown“ ..it is totally burned away. Even the idea to parallel those 2 packs with just a cheap nickel strip shows the lack of knowledge over there at Gotways... Link to comment Share on other sites More sharing options...
FreeRide Posted November 19, 2017 Share Posted November 19, 2017 I think you can save the pack. the decision is what to use to make a new connection. you need to bridge it with something with more current capacity and I take it you don't have a spot welder. You can probably find some copper to use as a buss bar or even some heavy gauge wire. With some good flux you can probably solder onto the nickel strips close to the batteries where the resistance of the nickel would be a non issue. Sending the pack to a battery repair place might be a good idea, they could probably spot weld new thicker strips or use different materials. Since it sounded like your initial jam in the tunstiles was not too significant, I would be wondering if it had already been weakened by other events, or maybe at time of manufacturing with an unfortunate bend. Link to comment Share on other sites More sharing options...
jbwheel Posted November 19, 2017 Share Posted November 19, 2017 4 hours ago, Hunka Hunka Burning Love said: would get some flux, put some over the contacts Why not solder somewhere in the middle of the untouched nickel strip, between two cells ? And maybe another bond between the melted extremities. So you won't get to much heat to the cells. Also I don't understand why it hasn't melted on the welding spots... Anyone can see if this is a pure nickel strip ? 3 hours ago, KingSong69 said: pure fat copper strip should do the job! Have you ever done this ? Even a thin strip seems too difficult to weld. Link to comment Share on other sites More sharing options...
US69 Posted November 19, 2017 Share Posted November 19, 2017 1 hour ago, jbwheel said: Why not solder somewhere in the middle of the untouched nickel strip, between two cells ? And maybe another bond between the melted extremities. So you won't get to much heat to the cells. Also I don't understand why it hasn't melted on the welding spots... Anyone can see if this is a pure nickel strip ? Have you ever done this ? Even a thin strip seems too difficult to weld. I assume Marty has no spot welding machine, so i thought about soldering, exactly like you said would be optimal, between the 2 cells. Link to comment Share on other sites More sharing options...
Jrkline "Wheel Whisperer" Posted November 19, 2017 Share Posted November 19, 2017 3 hours ago, Rehab1 said: Great work Marty! GW owes you again! The bridge connection could have easily been attenuated during fabrication process of the packs if the strip was stretched thinner during the electronic welding process. Depending on the sequence of the numerous welds that process could have easily heated up the bridged metal strip and stretched it thin. Now the strip would carry less amperage across that site and melt just like a fuse. There would be no reason why you could not solder a 12awg wire across that site and then check the voltage to see if the packs are ok. I am willing to bet the board survived. Good luck buddy. I miss those autopsy days. You are probably right about the strip possibly being stretched a little. @Marty Backe got really lucky that it is a simple nickle strip failure and not someplace else like the BMS.And this is NOT a Gotway design flaw.All packs are constructed the same way whether it be in EUC's,laptops,battery powered tools etc. @Marty Backe's Mten3 failure is a freak occurance.I got my Mten3 the same day @Marty Backe got his and my wheel is just fine.The only reason he even opened the battery was because I asked him yesterday on our group ride if he had checked the battery voltage yet and he said no and would test it later. Link to comment Share on other sites More sharing options...
US69 Posted November 19, 2017 Share Posted November 19, 2017 24 minutes ago, Jrkline "Wheel Whisperer" said: probably right about the strip possibly being stretched a little. @Marty Backe got really lucky that it is a simple nickle strip failure and not someplace else like the BMS.And this is NOT a Gotway design flaw.All packs are constructed the same way whether it be in EUC's,laptops,battery powered tools etc. Sorry, i have to contradict that. There are several ways to design a 20s2p pack... For once, you can setup 2 different 20s packs and parallel these 2 packs.....what not happend here. From what i see, they paralled 2 cells over the complete pack, and serial this 2 times parrallel cells a 20 times. That leads to this one strip, which sits in the middle of the complete pack and in this case has to take the complete current draw of the hole battery pack! That can be designed much better, and it is, even on other GW packs! On this special strip, the amperage is (at least) double as high as on any other strip in the pack, and that lead to this burn. As others have stated a nickel strip like this can take about 8—15 Amps...while alone the 2s20s are able to give 2x10amps (peek even more). And i highly doubt that the Mten „only“ draws a 20Amp max. When i upgraded my v3 to 1160wh i had a deep lecture about this from 1radwerkstatt, when he made one pack out of my 2 420wh packs. Maybe on your Mten it is „still“ working ok...but afaik yours is newer...and if you do some more idling on it like Marty, and we will see how it goes...as long as GW is not putting a better connection here (or redesigning the pack) a warning to MTen3 users is at least reasonable. Link to comment Share on other sites More sharing options...
Jrkline "Wheel Whisperer" Posted November 19, 2017 Share Posted November 19, 2017 4 minutes ago, KingSong69 said: Maybe on your Mten it is „still“ working ok...but afaik yours is newer...and if you do some more idling on it like Marty, and we will see how it goes...as long as GW is not putting a better connection here (or redesigning the pack) a warning to MTen3 users is at least reasonable. Normally the "weak" point of a nickle strip is at the spot weld.His failed in the center as if it had been stretched or creased somehow.I have disassembled many battery packs and whether it be Gotway,KingSong,Sony,Dewalt etc.,they are all constructed pretty much the same way. Link to comment Share on other sites More sharing options...
Marty Backe Posted November 19, 2017 Author Share Posted November 19, 2017 Everyone, thank you very much for your replies, concerns, suggestions, etc. I really appreciate the sentiments that you've expressed. I'm leaning towards throwing the battery pack away. With my naked eyes I could not see some of the damage, but when reviewing the macro video shots I can see that at least one of the cells is damaged and that there is battery 'juice' near the burnt strip. These battery packs are highly manufactured, and I don't think that I want to trust my body riding on a wheel where I've hacked it back together. Maybe I would attempt a repair if I had the requisite knowledge and experience, but I don't. The construction of the battery case and battery pack is actually impressive - somehow I doubt Gotway actually makes these because they look too good. It's the lack of system design that placed too much of a load on the battery. As @Jrkline "Wheel Whisperer" says, there are all made like this one. We all know the difficulties of attempted communication with Gotway or Chinese resellers. It's the risk that we take, or at least I'm willing to take to experience the joys of wheels such as the Mten3. I do not think that the battery pack itself is defective, but Gotway's system design is lacking (to say the least). They should engineer a wheel such that the battery pack is protected by either a fuse or a more sophisticated power electronics design. @eddiemoy, I've said this time and time - it's not blind loyalty to Gotway. It's my desire to experience wheels that exist no where else. Please direct me to where I can buy an alternative to the Mten3. If there were actual comparable wheels but of higher build/design quality than Gotway, I would not buy a Gotway wheel. This is why I own a KS14S and not the Gotway MCM. @Duf, please don't be down on the Mten3, or consider it a safety hazard. I put mine through amazing stresses with all of the heavy reversals (my videos only showed a tiny fraction of what I've done). This was a case of me causing extreme power demand from the battery. Because of Gotway's poor system design, the battery failed instead of the MOSFETs. Normal riding at speed does not require huge power demands. I will either purchase a new Mten3 or battery, but I will have an Mten3 in my life. I love this wheel. @Rehab1, Gotway may "owe me one", but I think we both know that they will probably never get this feedback or do anything about it I'll send this info to the Green Traveling shop, but that's pretty much a black hole (I assume). I'm still Gotway's biggest fanboy, but I'm never going to keep from exposing crappy design or manufacturing from the light of day to protect their (or any company) image. I buy all of my products so I owe nobody preferred treatment. I'm always dubious of 'reviews' by people who are given products. In case there's any doubt, everyone still needs to buy an Mten3 to experience the joys of this wheel But I sure wouldn't mind if KingSong released a 10-inch wheel Link to comment Share on other sites More sharing options...
US69 Posted November 19, 2017 Share Posted November 19, 2017 13 minutes ago, Jrkline "Wheel Whisperer" said: Normally the "weak" point of a nickle strip is at the spot weld.His failed in the center as if it had been stretched or creased somehow.I have disassembled many battery packs and whether it be Gotway,KingSong,Sony,Dewalt etc.,they are all constructed pretty much the same way. I would go with you ...if: - there would be any possibility for stretching...but it is glued in the middle and sits in a black box, also glued - and for the constriction, again, here is the hole load on one strip...that is not needed and can be avoided in a cleverer design Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted November 19, 2017 Share Posted November 19, 2017 Maybe give the pack to @Jrkline "Wheel Whisperer" to see if he can repair the bridge as he has a lot of experience making his own super-packs. Maybe he can replace the damaged cells if they are leaking? It just seems to me a waste especially if the BMS is intact and the majority of the cells are still in working order. I would be curious to see if those battery strips are pure nickel or nickel coated steel. Maybe a small piece removed from the burned / separated area sanded and test could be tested. If the nickel tab bridge heated up due to the current draw, I wonder if it may have melted the adjacent battery plastic cover protecting the casing of the cell leading to it getting shorted out. A careful examination of the cells near the bridge might be wise to check for any insulation damage. Link to comment Share on other sites More sharing options...
steve454 Posted November 19, 2017 Share Posted November 19, 2017 Maybe sell the battery to @Jrkline "Wheel Whisperer" so he can salvage any good cells and add them to one of his wheels. Link to comment Share on other sites More sharing options...
Marty Backe Posted November 19, 2017 Author Share Posted November 19, 2017 5 minutes ago, Hunka Hunka Burning Love said: Maybe give the pack to @Jrkline "Wheel Whisperer" to see if he can repair the bridge as he has a lot of experience making his own super-packs. Maybe he can replace the damaged cells if they are leaking? It just seems to me a waste especially if the BMS is intact and the majority of the cells are still in working order. I would be curious to see if those battery strips are pure nickel or nickel coated steel. Maybe a small piece removed from the burned / separated area sanded and test could be tested. If the nickel tab bridge heated up due to the current draw, I wonder if it may have melted the adjacent battery plastic cover protecting the casing of the cell leading to it getting shorted out. A careful examination of the cells near the bridge might be wise to check for any insulation damage. I haven't dug deeper yet, but unless I'm not understanding something about these battery packs, it's not possible to isolate individual battery cells without some destruction in the process. It's not like you can plop a battery out and inspect it with a meter. These battery packs are highly manufactured difficult to disassemble/reassemble with specialized knowledge and equipment. Given the choice of $400 or physical injury and associated medical costs, I'll go with the simpler option of $400. I like to know the cause of a failure (which I think I did here), but batteries aren't my hobby so I'm not likely to investigate much further. I've already texted @Jrkline "Wheel Whisperer" telling him he can have the battery pack when I'm done with it. Link to comment Share on other sites More sharing options...
Marty Backe Posted November 19, 2017 Author Share Posted November 19, 2017 7 minutes ago, steve454 said: Maybe sell the battery to @Jrkline "Wheel Whisperer" so he can salvage any good cells and add them to one of his wheels. He can have them for free Link to comment Share on other sites More sharing options...
Sketch Posted November 19, 2017 Share Posted November 19, 2017 @Marty Backe I’m really sorry you have to deal with this. I have to say, I’ve been riding my Mten3 for a couple of days and it had been a blast. I’m really glad I followed your advice in getting one and can imagine how frustrating it would be to have yours not working. I will have to say that I’m sure many Mten3 have been sold and used and this is the only case of this kind I have heard about. I’m not saying Gotway can’t make it better, but it doesn’t mean they all are gong to fail like this. I appreciate Marty and his willingness to document all his experiences and findings. It benefits the rest of us. Until I see massive numbers of people having problems, I’m not going to stop riding it. I sure @Jason McNeil my distributor is looking into it and will give us info if this is a wide spread safety issue. We all know what we are getting ourselves into with any EUCs and failures do happen. If it fails on me it will probably be at low speeds. This is a fun around town manuvering machine. Marty, I know you feel the same and I hope you can get up and running soon. By the way, I have never been that great at backwards riding until I tried the Mten3. It’s way easier to ride backward than any other wheel I have used. I think it’s the combo of it’s wide wheel and high maneuverability characteristics.? Link to comment Share on other sites More sharing options...
Marty Backe Posted November 19, 2017 Author Share Posted November 19, 2017 56 minutes ago, Sketch said: @Marty Backe I’m really sorry you have to deal with this. I have to say, I’ve been riding my Mten3 for a couple of days and it had been a blast. I’m really glad I followed your advice in getting one and can imagine how frustrating it would be to have yours not working. I will have to say that I’m sure many Mten3 have been sold and used and this is the only case of this kind I have heard about. I’m not saying Gotway can’t make it better, but it doesn’t mean they all are gong to fail like this. I appreciate Marty and his willingness to document all his experiences and findings. It benefits the rest of us. Until I see massive numbers of people having problems, I’m not going to stop riding it. I sure @Jason McNeil my distributor is looking into it and will give us info if this is a wide spread safety issue. We all know what we are getting ourselves into with any EUCs and failures do happen. If it fails on me it will probably be at low speeds. This is a fun around town manuvering machine. Marty, I know you feel the same and I hope you can get up and running soon. By the way, I have never been that great at backwards riding until I tried the Mten3. It’s way easier to ride backward than any other wheel I have used. I think it’s the combo of it’s wide wheel and high maneuverability characteristics.? Hey @Sketch! I'm really glad that you are enjoying the Mten3. I knew the Mten3 would be easier to ride backwards. You'll eventually get really good at it and you'll see that it transfers to a great degree to your other wheels. I am sad that my Mten3 currently looks like a disassembled C-3PO, but I'm hopeful that I may get it working before the end of the year. And finally, I'm glad that you are looking at my experience rationally instead of, "I'm never riding that thing again", or buy Gotway again, as so many people are apt to do You got your Tesla too, right? Good times Link to comment Share on other sites More sharing options...
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