Jez_Fila Posted November 22, 2015 Share Posted November 22, 2015 Hi Guys, New to the forum but been riding for about 2 months now. I have a TG-T3 which I bought quite cheaply as I was not sure about the whole UE thing. I love it and find it is an great way to get about. Some things that I have noticed on the T3 which I need some advice from those more knowlegable than I: 1. When I first bought it it never charged to 4 lights. The light on the charger goes green, but when I start up the unicycle there is never more than three lights out of 4 lit up. At first I suspected that the battery has some dead cells. Not sure how to test for this? 2. The unicycle seems to run out of juice fast! I think that the lights to down to 1 after 5-10 minutes of use. 2-3kms seems it be its limit and possibly less if there is a hill. 3. I shunted the BMS because I was getting faceplant shutdowns randomly. Usually on a hill it would just shut off and throw me. After doing this I have not experienced a shutdown but something different has happened. After a ride when the uni got to one battery the lights started to flash (all) and the UE started to beep. It also tilted back. I had never experienced this before. I am thinking that this is the way the battery tells you its properly out of power after the BMS has been shunted? Its definitely better than getting thrown onto the pavement. Maybe I shunted the BMS wrong? 4. Tyre inflation. I find that when I over inflate the tire it uses less power, but on the other hand is a little harder to control side to side. What would be the ideal tire inflation on these? it says 36-45. I weigh 88kg. Thanks in advance Link to comment Share on other sites More sharing options...
Chriull Posted November 23, 2015 Share Posted November 23, 2015 1) You can test the battery for dead cells by opening the battery pack and measuring the voltage of each individual cell (or all the 2 cells, which are in parallel). If you look at the pics of the BMS PCB in http://forum.electricunicycle.org/topic/459-electric-unicycles-bms-problem-and-solution/ you have solder points labeled with V1 till V15 (or more or less - depending on the number of cells in series). So you can measure the different cells between V1 and V2, V2 and V3 and so on. If you have dead/bad cells you should notice a different voltage. In some of the other threads or on http://batteryuniversity.com/ you can find the nominal/maximal/minimum sane voltages for Li Ion cells. If you did the shunting by connecting P- with B- it could be, that you shunted a couple of cells "away", if you got a wrong soldier point for B-? If all of the cells are ok, it still could be the charger? You already measured the voltage the charger supplies without load/while charging? 3) Tilting should be the normal behaviour. So it seems, that you did the shunting right. But if this is a new behaviour you already had currents flowing, where the BMS would have shut off - so in the worst case you could "overload" the MOSFETs driving the motor. Edit: This "overloading" of the MOSFETs should not be dramatic - imho the chance to kill the MOSFETS should be quite low. But to be on the secure side, you just could drive more gentle/not as fast once you notice the new behaviour... Link to comment Share on other sites More sharing options...
Jez_Fila Posted November 23, 2015 Author Share Posted November 23, 2015 Thanks for that! Its interesting. Now that I have shunted it, instead of a cuttoff i have flashing and gradual tiltback. The thing about the tiltback is that it flashes and keeps going. i.e. if i lift up the UE it will keep running the wheel and flashing. I can almost get it to the point it tiltrs back to the point it needs to be turned upside down to change direction. (at this point i am holding the UE by the handle and tilting it. The mod i used was by shorting all 3 T1's bypassing shutoff though solder blob. I tried running a wider from P- to B- but that did not seem to work. Still got a shutoff. should I run a wire from one of the T1's ive soldered to B-? Link to comment Share on other sites More sharing options...
Chriull Posted November 24, 2015 Share Posted November 24, 2015 2 hours ago, Jez_Fila said: The mod i used was by shorting all 3 T1's bypassing shutoff though solder blob. Ok. Seems like its working fine. 2 hours ago, Jez_Fila said: I tried running a wider from P- to B- but that did not seem to work. Still got a shutoff. Then you got something wrong trying this - it's both more or less the same. 2 hours ago, Jez_Fila said: should I run a wire from one of the T1's ive soldered to B-? No. The connection is already on the board. Link to comment Share on other sites More sharing options...
Jez_Fila Posted November 25, 2015 Author Share Posted November 25, 2015 One think that I have noticed is that whatever I have done has limited the range by quite a bit. Positive is that no more cut off, but the range has severely reduced before the flashing and tilt back starts. I can keep riding through it as it keeps tilting back harder and harder! Turning off and on helps a little but not for long. Before shunting it would through me off and then make me wait 10 minutes, by then I can turn on again and go. But this is wierd because the tilt back starts before i even do 1 KM! Wondering if this could be caused becuase I shunted all 3 of the T1 (Q1) Mosfets? Should I un-shunt the one to the rightmost side? Link to comment Share on other sites More sharing options...
Jurgen Posted November 25, 2015 Share Posted November 25, 2015 I have mine at 4bar (58psi) at 100Kg it's harder and more nervous to ride and has less grip on loose underground but you have more control when pushing hard and riding of sidewalks, faster reaction times if you're a newby I would go for around 3 bar Link to comment Share on other sites More sharing options...
Chriull Posted November 25, 2015 Share Posted November 25, 2015 7 hours ago, Jez_Fila said: One think that I have noticed is that whatever I have done has limited the range by quite a bit. Positive is that no more cut off, but the range has severely reduced before the flashing and tilt back starts. I can keep riding through it as it keeps tilting back harder and harder! Turning off and on helps a little but not for long. Before shunting it would through me off and then make me wait 10 minutes, by then I can turn on again and go. But this is wierd because the tilt back starts before i even do 1 KM! Wondering if this could be caused becuase I shunted all 3 of the T1 (Q1) Mosfets? Should I un-shunt the one to the rightmost side? You are quite eager in not trusting in your shunting The lower range is definitely not in because of shunting all of the three mosfets. The are in parellel anyhow on the board - which you can doublecheck easily by looking at the board layout. If the three legs of the three mosfets you shunted are not connected on the motherboard, you shunted a wrong one - there is a fourth mosfet, which is for charging (overvoltage protection) and which should stay unshunted. However shunting this fourth mosfet want limit your range - it just makes charging unsafer... Around my place it started to get colder the last week - could be just the temperature drop. Colder Li Ion batteries have noticeable less charge. You mentioned battery/charger problems in the beginning. If you have bad/dead cells in the the pack, the can easily have got worse quite fast. Also in one thread was written, that there were problems with the cell balancing while/after charging - charging once every cell by its own was imho the solution. You already had a chance to measure the individual cell voltages? Link to comment Share on other sites More sharing options...
Jez_Fila Posted November 26, 2015 Author Share Posted November 26, 2015 16 hours ago, Jurgen said: I have mine at 4bar (58psi) at 100Kg it's harder and more nervous to ride and has less grip on loose underground but you have more control when pushing hard and riding of sidewalks, faster reaction times if you're a newby I would go for around 3 bar Ok so I will pump my tires a bit more. 15 hours ago, Chriull said: You are quite eager in not trusting in your shunting The lower range is definitely not in because of shunting all of the three mosfets. The are in parellel anyhow on the board - which you can doublecheck easily by looking at the board layout. If the three legs of the three mosfets you shunted are not connected on the motherboard, you shunted a wrong one - there is a fourth mosfet, which is for charging (overvoltage protection) and which should stay unshunted. However shunting this fourth mosfet want limit your range - it just makes charging unsafer... Around my place it started to get colder the last week - could be just the temperature drop. Colder Li Ion batteries have noticeable less charge. You mentioned battery/charger problems in the beginning. If you have bad/dead cells in the the pack, the can easily have got worse quite fast. Also in one thread was written, that there were problems with the cell balancing while/after charging - charging once every cell by its own was imho the solution. You already had a chance to measure the individual cell voltages? Here's something interesting. The middle leg of each of the mosfets doesnt touch the board. Only the left and right. The middle one is shorter. Does this make any difference? I'm in Australia and its quite warm here so I dont think the range is because of temperature. I may take a picture of my work on the weekend and put it up so you can see what I have done. I havent checked the individual batteries cells yet. I have a multimeter but not sure how to use it against the cells in the pack so I can get individual cell voltages. Charging cells individually? Not sure how I would do that. I should say I am a novice at electronics but a quick learner. Link to comment Share on other sites More sharing options...
SuperSport Posted November 26, 2015 Share Posted November 26, 2015 I also had the battery issues you describe on my TG F3. Bought it from BangGood.com and they are sending me a new battery after I described the problem. But I only bought it less than a week ago, so it might be harder for you to get a replacement. Also, I have not shunted yet. Also, my charger was only putting out about 62 volts without a load. I was told to bring it up to 67.2, so I did. Adjusted it inside the charger. Link to comment Share on other sites More sharing options...
Jez_Fila Posted November 26, 2015 Author Share Posted November 26, 2015 I bought my from tmart.com. I contacted them with my concerns and they said that they would replace it. However the cost to ship it back to them was prohibitive $$$ and they would not just ship another battery. Link to comment Share on other sites More sharing options...
SuperSport Posted November 26, 2015 Share Posted November 26, 2015 Yeah, I was concerned about that too. Fortunately, they are shipping an additional battery and I don't need to send back the original. Link to comment Share on other sites More sharing options...
Chriull Posted November 26, 2015 Share Posted November 26, 2015 9 hours ago, Jez_Fila said: Here's something interesting. The middle leg of each of the mosfets doesnt touch the board. Only the left and right. The middle one is shorter. Does this make any difference? No. The middle leg (drain) has an internal connection to the "backside" of the moset, by whichnit has contact to the board. 9 hours ago, Jez_Fila said: I'm in Australia and its quite warm here so I dont think the range is because of temperature. I may take a picture of my work on the weekend and put it up so you can see what I have done. I havent checked the individual batteries cells yet. I have a multimeter but not sure how to use it against the cells in the pack so I can get individual cell voltages. You can measure it as described in my above post. 9 hours ago, Jez_Fila said: Charging cells individually? Not sure how I would do that. I should say I am a novice at electronics but a quick learner. First you should check the charger, as SuperSport mentioned. If its not working correctly you can maybe adjust it/by a new one. if thats not the reason you should check the individula cells. Then sou can charge (with a seperate charger) or replace the bad cells, or jusr by a new battery pack. Maybe you have to replace/repair both. Link to comment Share on other sites More sharing options...
SuperSport Posted November 26, 2015 Share Posted November 26, 2015 5 hours ago, Chriull said: Maybe you have to replace/repair both. That's where I'm at. Mine came with a bad Charger and Battery. I've adjusted the Charger so it will work, but BangGood is sending a new battery. Good on them... The battery for your's only runs about $60. I know that sucks, but it's better than not being able to ride anymore. Chargers are as low as $15. But, you might be able to adjust it. Probably the same charger I got. If I get a chance, I'll make a video showing how I adjusted it. Link to comment Share on other sites More sharing options...
Jez_Fila Posted November 29, 2015 Author Share Posted November 29, 2015 I bought my from tmart.com. I contacted them with my concerns and they said that they would replace it. However the cost to ship it back to them was prohibitive and they would not replace just the battery. I've bit the bullet and just ordered the replacement battery last week from banggood. I opted for the 174kwh instead of my 132kwh for the extra couple of dollars. The performance on mine has been getting worse. The shunting has meant that I no longer have cuttoffs, however the range in it has been gradually getting worse. To the point now I can barely do one kilometer before flash beeping and titlback! I don't think that its necessarily due to lack of charge either! When its starts flashing and tilting back, I can usually turn it off and restart and it will go for a few hunded metres more. It depends on how hard I accelerate too. If i go faster it will warn me earlier. If I go slower it may last longer. I also noted that I never had a problem downhill. probably because of the regenerating of the battery? Not sure. It could be that there is an issue with the circuitry work or the batteries are unstable. No idea. I am not sure if any of these symptoms are ringing a bell? It would be off if I were the only one having issues like this. Hopefully the new batteries will make a difference. I will not shunt them straight away as I want to test them out first. I dont do great distances daily. Perhaps 1-2 kms between charges, no more. I weigh around 88KG. This could make a difference. I checked the battery voltage fully charged with a multimeter and noticed som minor variations. The cells averaged at around 3.7V. Also measured V1 to V2 etc. Ans it showed a range of 14.7V to 15.4V. Not sure if I was checking correctly. Charger was putting out over 67.2. It fluctuated between this and 68. Mostly at the higher end. My charger does not have the ability to be toggled to different voltage. Link to comment Share on other sites More sharing options...
SuperSport Posted November 30, 2015 Share Posted November 30, 2015 6 hours ago, Jez_Fila said: Charger was putting out over 67.2. It fluctuated between this and 68. Mostly at the higher end. My charger does not have the ability to be toggled to different voltage. They aren't a simple switch, you have to open the case and make an adjustment on the motherboard. But it sounds like yours is outputting just fine, so no need. I think your battery choice was a good one... Link to comment Share on other sites More sharing options...
Chriull Posted November 30, 2015 Share Posted November 30, 2015 17 hours ago, Jez_Fila said: ... I checked the battery voltage fully charged with a multimeter and noticed som minor variations. The cells averaged at around 3.7V. According to http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries with ~3,7V are about half empty. Did you measure this after freshly charging your battery pack? Normaly after charging they should have about 4,1-4,2V per cell. Imho - there are people here with more experience with the Li Ion cells... 17 hours ago, Jez_Fila said: 17 hours ago, Jez_Fila said: Charger was putting out over 67.2. It fluctuated between this and 68. Mostly at the higher end. My charger does not have the ability to be toggled to different voltage. That should be ok for a 16 cell pack - that would be the 4,2V per cell fully charged... Once you got your new battery pack (which is hopefully ok) you will know the exact reason Link to comment Share on other sites More sharing options...
Jez_Fila Posted November 30, 2015 Author Share Posted November 30, 2015 6 hours ago, Chriull said: According to http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries with ~3,7V are about half empty. Did you measure this after freshly charging your battery pack? Normaly after charging they should have about 4,1-4,2V per cell. Imho - there are people here with more experience with the Li Ion cells... That should be ok for a 16 cell pack - that would be the 4,2V per cell fully charged... Once you got your new battery pack (which is hopefully ok) you will know the exact reason Yes it was freshly charged. It could be that the batteries already have a diminished capacity. it was also the average so it may vary between cells. Link to comment Share on other sites More sharing options...
Chriull Posted November 30, 2015 Share Posted November 30, 2015 ... or the charger only has the right voltage while running idle - but as written above, you'll see once you have your new battery pack. Link to comment Share on other sites More sharing options...
Jez_Fila Posted November 30, 2015 Author Share Posted November 30, 2015 13 minutes ago, Chriull said: ... or the charger only has the right voltage while running idle - but as written above, you'll see once you have your new battery pack. So you think that it might be the charger not doing its job? Whatever it is it seems that the light doesn't take long to get to green, almost as if it's not charging fully or something. Link to comment Share on other sites More sharing options...
SuperSport Posted December 1, 2015 Share Posted December 1, 2015 28 minutes ago, Jez_Fila said: So you think that it might be the charger not doing its job? Whatever it is it seems that the light doesn't take long to get to green, almost as if it's not charging fully or something. That's how mine acts. Waiting for the replacement battery, then I'll know. Link to comment Share on other sites More sharing options...
Chriull Posted December 1, 2015 Share Posted December 1, 2015 8 hours ago, Jez_Fila said: So you think that it might be the charger not doing its job? Whatever it is it seems that the light doesn't take long to get to green, almost as if it's not charging fully or something. It's not possible to say this now. If you look at http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries the charger should work as constant current source in the first stage, until the voltage rises to 16*4,2V=67,2V and then charge with a constant voltage of 67,2V until the current drops below some threshold (saturation charge). So if your charging goes to fast it could be some malfunctioning of the charger or bad battery cells - you will know when you get your new battery pack or you can do some voltage measuring while charging and maybe we get a clue whats going on... ... Or you order a new charger just in case - imho they are quite cheap (from what think to remember from some threads around here...) Then you have quite good chances to have a "working" system again, once both arrives and in the worst case you have a spare charger... Link to comment Share on other sites More sharing options...
electric_vehicle_lover Posted December 1, 2015 Share Posted December 1, 2015 @Jez_Fila 3) that is done by the controller and not by the battery pack/BMS. The controller just reads the battery voltage and is programmed to do that on low battery voltage. The controller also controls the LEDs. We are making an OpenSource firmware and so we are exploring how the controller and that generic EUC works :-) Link to comment Share on other sites More sharing options...
Jez_Fila Posted December 1, 2015 Author Share Posted December 1, 2015 2 hours ago, electric_vehicle_lover said: @Jez_Fila 3) that is done by the controller and not by the battery pack/BMS. The controller just reads the battery voltage and is programmed to do that on low battery voltage. The controller also controls the LEDs. We are making an OpenSource firmware and so we are exploring how the controller and that generic EUC works :-) Hmmm... I cant remember what its like inside I'll have to take it apart again, but what if I bypassed the controller and charged the batteries directly measuring the voltage? I also assume the Overcharge protection on the BMS will not allow the batteries get overcharged? Link to comment Share on other sites More sharing options...
electric_vehicle_lover Posted December 1, 2015 Share Posted December 1, 2015 The BMS controls the battery charge and discharge. The controller also controls the behavior of the motor, buzzer and LEDs. It have as input the battery voltage. Link to comment Share on other sites More sharing options...
Jez_Fila Posted December 1, 2015 Author Share Posted December 1, 2015 1 minute ago, electric_vehicle_lover said: The BMS controls the battery charge and discharge. The controller also controls the behavior of the motor, buzzer and LEDs. It have as input the battery voltage. OK I understand what you are referring to now. I thought you mean the battery charge stopping. You are referring to the behavior of the Unicycle at low charge or during acceleration making it tilt back at certain points. The firmware you are developing is for a TG-T3? Link to comment Share on other sites More sharing options...
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