matt Posted July 3, 2017 Share Posted July 3, 2017 Hi, so my EUC is probably about 1,5 years old (I'm the second owner) and it has < 100 km mileage. A few days ago I almost completely "emptied" the batteries riding it and forgot to turn it off at home afterwards. It started to beep in the middle of the nigh, as the batteries must have gone to zero in the "standby" mode. (By the way the batteries level as shown in the app has always been a little, hmm... dubious.) Since than, the diode on the charger goes to red for about 15 sec. and then it goes to green, i.e. it stops charging. Great. Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 3, 2017 Share Posted July 3, 2017 Does the wheel still turn on? Try opening the wheel and disconnecting the battery for a few minutes, both, the balancing wires (two connectors with mainly white small wires) and the main power connector. Measure the battery voltage directly at the power connector. Be careful not to short anything, there is no protection on the battery itself, that's all in the control box. Link to comment Share on other sites More sharing options...
matt Posted July 3, 2017 Author Share Posted July 3, 2017 Yes, it still turns on. I'll try to do what you said, thanks. Hope I can identify the right cables. Link to comment Share on other sites More sharing options...
matt Posted July 10, 2017 Author Share Posted July 10, 2017 I've tried disconnecting the wires, didn't help I haven't measured the voltage yet. Link to comment Share on other sites More sharing options...
matt Posted July 10, 2017 Author Share Posted July 10, 2017 The charger voltage is 66,7, and in the yellow connector of black and red wires there's 44,4. Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 10, 2017 Share Posted July 10, 2017 44,4 is quite a bit low... Low enough for the BMS to regard the battery as broken and not let you charge it. Please check all the single voltages of each cell, you can do this on the connectors with the many white wires. There should be one black wire on those, that's your 0 V reference aka the negative pole of the first cell, and on the second connector one or two red wires, that's the positive pole of the last cell. 44,4 V in a 16s battery would give you an average cell voltage of 2,775 V, which is not good on the one hand, but not too bad. Check if there is any cell that' below 2 V. If there isn't, I would try to charge the battery directly without the BMS by connecting the charger directly to the yellow XT60 connector of the battery, and closely monitor alle those individual voltages until the battery is up to about 55V, then reconnect everything and it should charge normally afterwards. However, be careful in what you're doing as even this "empty" battery can still produce quite a nice arc if shorted... If there are cells below 2V, this all gets quite a bit riskier, single cell voltages during charging must be monitored! If you have a cell with 0V or even a negative voltage you will need to replace those cells... If you can't do that, you will need a new battery. Link to comment Share on other sites More sharing options...
Chriull Posted July 10, 2017 Share Posted July 10, 2017 33 minutes ago, Slaughthammer said: ... 44,4 V in a 16s battery would give you an average cell voltage of 2,775 V, which is not good on the one hand, but not too bad. Check if there is any cell that' below 2 V. If there isn't, I would try to charge the battery directly without the BMS by connecting the charger directly to the yellow XT60 connector of the battery, and closely monitor alle those individual voltages until the battery is up to about 55V, then reconnect everything and it should charge normally afterwards...th 0V or even a negative voltage you will need to replace those cells... Could be a very nice way to revive the pack! Just a short repetition for @matt, that he does not miss the most important part: "closely monitor alle those individual voltages"! No cell is allowed to go over 4,2V! Also a cell beeing at higher charge then the others could be a prob once the pack gets charged full with the BMS connected again - don't know if any balancing works with his wheel while charging and when if it is capable of "taking out" a fully charged cell... (both imho quite uncommon ;( ) @matt: do you have extra balancing wires at your battery pack? If not you'd have to open the pack for individual cell voltage measurement... - be carefull to not shorten anything by accident! Edit: Imho the best solution if there are quite some differences in the different cell voltages would be to charge each of the 16 paralleled cells seperately, if you have such a LiIon Charger... Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 10, 2017 Share Posted July 10, 2017 1 minute ago, Chriull said: Just a short repetition for @matt, that he does not miss the most important part: "closely monitor alle those individual voltages"! No cell is allowed to go over 4,2V! Oh, should have mentioned that, my bad! 1 minute ago, Chriull said: do you have extra balancing wires at your battery pack? Yes, the IPS Zero has the BMS integrated in the main control board (same as the Lhotz), thus all the balancing wires. Makes wiring inside the wheel a mess, but comes in handy at some occasions. Link to comment Share on other sites More sharing options...
Chriull Posted July 10, 2017 Share Posted July 10, 2017 2 minutes ago, Slaughthammer said: Yes, the IPS Zero has the BMS integrated in the main control board (same as the Lhotz), thus all the balancing wires. Makes wiring inside the wheel a mess, but comes in handy at some occasions. Ups - i thought i've seen the wheel name somewhere, but then could not find it anymore ... since it was hidden in the topic name .... Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 10, 2017 Share Posted July 10, 2017 8 minutes ago, Chriull said: Also a cell beeing at higher charge then the others could be a prob once the pack gets charged full with the BMS connected again - don't know if any balancing works with his wheel while charging and when if it is capable of "taking out" a fully charged cell... (both imho quite uncommon ;( ) If there is a cell with a particular high voltage (which I regard as rather unlikely in this situation) it's probably best to do some manual balancing before going back to using the BMS for charging. Just connect a consumer that usually runs on a single lithium cell to any high voltage cells until the voltage has dropped enough. That's some tedious work... However, the IPS BMS works quite well at balancing the cells. Link to comment Share on other sites More sharing options...
matt Posted July 14, 2017 Author Share Posted July 14, 2017 So the batteries were charged to about 55V through the yellow connector, but after that the normal route charging was still not possible. Now someone with basic electric knowledge is trying to locate the malfunctioning ones. Can you tell me what their specs are and point a good place to buy them (when ordering from Europe)? By the way, when posting here I also sent a message to IPS with the link to the thread. No answer. Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 14, 2017 Share Posted July 14, 2017 Did you check the individual voltages through the balancing wires? The cells used in the IPS 340Wh batteries should be these: https://eu.nkon.nl/rechargeable/18650-size/panasonic-ncr18650pf-3-7v-2900mah.html (by the way one of the best online shops for 18650s in Europe) Link to comment Share on other sites More sharing options...
matt Posted July 14, 2017 Author Share Posted July 14, 2017 Thanks for the link. The lowest voltage measured the way was 0,9, but, being green, I'm not sure if this was done correctly. Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 14, 2017 Share Posted July 14, 2017 0,9V sounds plausible.... when the cells are discharged that far, imbalances tend to stand out extremely. However, I'd try to charge the extremely low cells individually, but you need a special charger for that. If you don't know exactly what you're doing, better leave it to someone who does. Link to comment Share on other sites More sharing options...
matt Posted July 14, 2017 Author Share Posted July 14, 2017 There's a guy repairing TVs nearby, but he won't touch it. A would prefer to avoid sending it to a specialist, to avoid costs. My father is going to try to identify the faulty cells to replace them. Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 14, 2017 Share Posted July 14, 2017 Do you have someone who deals with RC models? They usually have quite a bit expertise about batteries, maybe get some help there? Link to comment Share on other sites More sharing options...
matt Posted July 14, 2017 Author Share Posted July 14, 2017 Actually there was such a guy next door to the TV guy, but i think he's moved away. Anyway, it's a big city, I could find another one. Link to comment Share on other sites More sharing options...
Chriull Posted July 14, 2017 Share Posted July 14, 2017 4 minutes ago, matt said: There's a guy repairing TVs nearby, but he won't touch it. A would prefer to avoid sending it to a specialist, to avoid costs. My father is going to try to identify the faulty cells to replace them. This could be a job for an electronic bycicle shop, if they sell self-made battery packs! Normally the cells are connected by spot welding - so not really trivial to replace without the proper euipment. Soldering should be possible, but it's easy to destroy the cells by doing so... 56 minutes ago, matt said: Thanks for the link. The lowest voltage measured the way was 0,9, but, being green, I'm not sure if this was done correctly. From http://batteryuniversity.com/learn/article/low_voltage_cut_off: "Do not boost lithium-based batteries back to life that have dwelled below 1.5V/cell for a week or longer. Copper shunts may have formed inside the cells that can lead to a partial or total electrical short. When recharging, such a cell might become unstable, causing excessive heat or show other anomalies. The Cadex “boost” function halts the charge if the voltage does not rise normal" (also the li ion cells in euc's should not have a protection circuit?) But anyhow - as written there "cells having under 1.5V for a week or longer" should not be reused! Link to comment Share on other sites More sharing options...
matt Posted July 14, 2017 Author Share Posted July 14, 2017 Hmmm... Starting to look less bright. I was wondering why not use soldering... Link to comment Share on other sites More sharing options...
Chriull Posted July 14, 2017 Share Posted July 14, 2017 These Li Ion cells are also sold with "solder tails" - maybe with some of them a nice replacement can be made? Depends mainly if in the battery pack solderable material was used to connect the other cells - so one can solder this tails on the old connections? Anyhow - be carefull messing around inside the pack - every short circuit can lead to imminent disaster! Link to comment Share on other sites More sharing options...
matt Posted July 14, 2017 Author Share Posted July 14, 2017 Could a wire be attached to a cell by mechanical force, for instance by a plastic clamp, by any chance? Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 14, 2017 Share Posted July 14, 2017 Just now, matt said: Could a wire be attached to a cell by mechanical force, for instance by a plastic clamp, by any chance? No, at least not for EUC applications. You can solder to the cells, but for that you really need to know what you're doing, and an appropriate soldering iron. The other, better option is spot welding nickel strips to the poles. Link to comment Share on other sites More sharing options...
US69 Posted July 14, 2017 Share Posted July 14, 2017 Just seen this -coincidentally- on Youtube, a method to build batterie packs without soldering: A complete kit for 50 batteries comes for 30 bucks... I doubt if it's very useful for EUC batteries....and yes, the connectivity is for sure not in the ligue of spotwelding....but for playing/experimenting with some batterie-cells/packs? Link to comment Share on other sites More sharing options...
Slaughthammer Posted July 14, 2017 Share Posted July 14, 2017 2 hours ago, KingSong69 said: I doubt if it's very useful for EUC batteries.... I can only agree. Especially for a Zero, the battery would become way to large to fit in. Additionally, I wouldn't trust this contraption to guarantee a good connection under all circumstances. OK for an e-bike, where battery failure means pedaling home, but not for en EUC, where battery failure equals faceplant. Link to comment Share on other sites More sharing options...
matt Posted July 27, 2017 Author Share Posted July 27, 2017 Hello again, I've not been able to deal with my "ride" recently, but I want to get back to the problem soon. I've just noticed solder tags options on the batteries from Slaughthammer's link. The question is: Do the mentioned problems with soldering apply to batteries with the tags too or just to regular ones? Link to comment Share on other sites More sharing options...
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