WakefulTraveller Posted April 23, 2016 Share Posted April 23, 2016 My MCM3 came with and currently has a 260 WH Sony battery, and it's just about powerful enough to make it all the way from where I work to home, with it coming to a crawl near the end of the journey. So I'm looking for something that can get me to work and back again without slowing down much. I'm thinking 680WH (or higher?) battery pack set will do nicely. Now there's a problem with this plan right from the start: the PCB is currently situated in the area where the second battery pack would normally go. There's this video below which shows how to relocate the EUC: To do this I will need: 1. A drill with a drill bit set (already on its way) 2. A tube of grey silicone gunk (I can pick some up at Home Depot or order it online.) Anyways. What is this even used as? Electrical insulation? Sealant? Glue? All of the above? Now once the PCB is relocated, the next step will be to install the two battery packs. Each pack will contain 32 cells. The part that I'm finding the most difficult is finding a set of battery packs. I've looked around online for someone that sells 32s battery packs that are put together in the same way as the GotWay battery packs and to no avail. I seeing a lot of 16s battery packs, but that's clearly not what I'm looking for. So I'm thinking that I might have to find someone to custom make the battery packs, and hope that they don't charge an arm and a leg and that they're put together properly. Or perhaps contact someone from GotWay? The cells of these packs are stacked diagonally to reduce thickness. Below is the 260WH battery to give you some idea of where it will fit: Once I have the battery packs, I will need some sort of power splitter I believe. Below are a couple of photos up the cables and the PCB: This is still very much still in the planning phase. I'm currently in the midst of making of pedal extension mod for my long feet. Hopefully this all goes well. Link to comment Share on other sites More sharing options...
esaj Posted April 23, 2016 Share Posted April 23, 2016 Ask around e-bike- or RC-shops or such, they might be able to make you pack with decent quality cells and BMS. 1Radwerkstatt also builds custom packs, but depending where you live, it might come costly with shipping & customs. Link to comment Share on other sites More sharing options...
Keith Posted April 23, 2016 Share Posted April 23, 2016 @WakefulTraveller, I get the impression we are going to be spending quite a lot of time saying "I told you so" we did all say that 260Wh wasn't enough to go 9 miles, adding the extra packs will almost certainly cost you more than getting a 680Wh wheel in the first place. There is so much you are not understanding that it is concerning as quite a lot of what you are aiming to do is dangerous. Your wheel has a 16S battery, not 32S which is why you cannot find one (thank God - the brief fire would have been quite spectacular!) It may well have 32 cells but that would be because it is a 16S2P pack. You want a good quality 16S pack of whatever capacity you want that will fit in the space you have. That capacity will, itself determine how many cells are in parallel, however, you are correct in that a 340Wh pack would typically be a total of 32 cells in 16s2p configuration. Read up, in this forum, or elsewhere, on how BMS work and, why, if you buy a cheap pack you might need to modify the BMS. Also read up on why packs have to be at the same state of charge when they are connected. Make damn sure positive goes to positive, etc and that, at no point can the packs wires touch each other (if you need to change connectors etc.) I have not quite got the willpower to trawl through how to move a Gotway main board (bearing in mind I have a KingSong) but I assume it does include telling you to reprogramme the board if the orientation changes, as it will not work without either exactly the same orientation or some sort of programming? Finally Silicone is the stuff that fish tanks get glued together with and bathtubs, washbasins, etc get sealed against the wall to stop water going behind them. It reacts with air catalytically and gives off acetic acid (vinegar) whilst curing which takes around a day. So, yes it is a glue and sealant and is not electrically conductive. Link to comment Share on other sites More sharing options...
esaj Posted April 23, 2016 Share Posted April 23, 2016 @Keith does make very good points, educate yourself on the batteries, so you don't end up buying wrong packs, electrocute yourself or cause a fire/explosion. Even cellphone/tablet batteries can make pretty spectacular fireworks, and they contain a fraction of the energy vs. a 16S2P pack (or two of them). The safest and easiest route is probably to sell your current wheel and get a new one with larger batteries. Link to comment Share on other sites More sharing options...
OliverH Posted April 23, 2016 Share Posted April 23, 2016 The main board is located on top under the handle with the 680 Wh setup: You started a real challenge. Link to comment Share on other sites More sharing options...
Keith Posted April 23, 2016 Share Posted April 23, 2016 13 minutes ago, OliverH said: The main board is located on top under the handle with the 680 Wh set-up You started a real challenge. Ahhhhhh. @OliverH, are you saying this video shows you how to fit the 680Wh main board, and not how to move the 260Wh board to a new position? If that is the case, @WakefulTraveller, you may not have found the answer you are looking for, as you cannot just reposition a main board without reprogramming it. I would take @esaj's advice if I was you. Link to comment Share on other sites More sharing options...
WakefulTraveller Posted April 23, 2016 Author Share Posted April 23, 2016 @Keith I'm still happy with my decision to go with only the 260WH initially. It was always my plan to upgrade the wheel if I felt that wasn't enough, which now appears to be the case. This was my first wheel, I wasn't 100% sure that I would fall in love with it, and I did not have the spare cash to buy a $1,000+ wheel at the time. Plus, it's not like I could have gotten the MCM3 at such a great price with any other battery option; 260WH was all that they were offering. You're right about me knowing next to nothing about battery packs. I was referring to the 16S2P configuration, naturally. @esaj I have no intention of building the pack myself, and simply plugging it in is not such a great risk in itself. However, if there's anything in particular that you are concerned about, feel free to mention it. I contacted Chen from Aliexpress and he said that he can sell the packs separately (as he normally ships them separately), so I will probably just buy them from him. -edit- @Keith I'm thinking that I'm just going to need to recalibrate it. I'm 99% positive that the PCB board is identical. Link to comment Share on other sites More sharing options...
OliverH Posted April 23, 2016 Share Posted April 23, 2016 Just now, Keith said: Ahhhhhh. @OliverH, are you saying this video shows you how to fit the 680Wh main board, and not how to move the 260Wh board to a new position? If that is the case, @WakefulTraveller, you may not have found the answer you are looking for, as you cannot just reposition a main board without reprogramming it. I would take @esaj's advice if I was you. It depends if the Mainboard would recalibrate. No idea if it's calibation or firmware related. It's may be worth to investigate. I would sell it or give it to someone in the family and buy an ACM 3 minutes ago, WakefulTraveller said: @Keith I'm still happy with my decision to go with only the 260WH initially. It was always my plan to upgrade the wheel if I felt that wasn't enough, which now appears to be the case. This was my first wheel, I wasn't 100% sure that I would fall in love with it, and I did not have the spare cash to buy a $1,000+ wheel at the time. Plus it's not like I could have gotten the MCM3 at such a great price with any other battery option; 260WH was all that they were offering. You're right about me knowing next to nothing about battery packs. I was referring to the 16S2P configuration, naturally. @esaj I have no intention of building the pack myself, and simply plugging it in is not such a great risk in itself. However, if there's anything in particular that you are concerned about, feel free to mention it. I contacted Chen from Aliexpress and he said that he can sell the packs separately (as he normally ships them separately), so I will probably just buy them from him. Maybe ask @Jane Mo for some advise in the case of the mainboard. Link to comment Share on other sites More sharing options...
esaj Posted April 23, 2016 Share Posted April 23, 2016 7 minutes ago, WakefulTraveller said: @esaj I have no intention of building the pack myself, and simply plugging it in is not such a great risk in itself. However, if there's anything in particular that you are concerned about, feel free to mention it. I contacted Chen from Aliexpress and he said that he can sell the packs separately (as he normally ships them separately), so I will probably just buy them from him. Nothing in particular and everything Some knowledge of potential hazards and common sense goes a long way. Plugging in batteries shouldn't be dangerous, just make sure to charge the packs to as exactly the same voltage as possible BEFORE connecting them. Small (< 1V?) voltage difference probably won't matter much, large difference can be a disaster, but I cannot give any exact values. 7 minutes ago, WakefulTraveller said: @Keith I really think that all I need to do is recalibrate the EUC for the change in orientation. I'm 99% positive that the PCB board is identical. It could work, or it could not. Better make sure of that before ordering the packs, ask @Linneaunicycles or @Jane Mo. You don't want to have gone through all the trouble and spending money, and then noticing it won't work. The thing is, the axes along which the backward/forward (pitch) and sideways (roll) tilts occur change if the board (ie. the gyro) is rotated to another position, so the firmware either has to be programmed in a way where it "knows" this and can switch to using other axes during recalibration, or be reprogrammed with a version that uses different axes. Link to comment Share on other sites More sharing options...
Keith Posted April 23, 2016 Share Posted April 23, 2016 9 minutes ago, WakefulTraveller said: @Keith @esaj I have no intention of building the pack myself, and simply plugging it in is not such a great risk in itself. However, if there's anything in particular that you are concerned about, feel free to mention it. Errrrrrr. Neither of us were suggesting that you built packs, it is worrying that you think just plugging them in is simple, it is not, at the very least you have to make up charging and power Y-leads, unless you can get a pair of packs designed to connect together. The rest of the issues with connecting two packs I've mentioned already. Assuming @OliverH is correct and recalibration is all that is required, (quite possible as it probably is the same board in both wheels) then you still have to ensure you do that correctly and the board is solidly, but not too solidly held down, any movement would make the wheel uncontrollable, but too rigid may make it react to vibration. Link to comment Share on other sites More sharing options...
WakefulTraveller Posted April 23, 2016 Author Share Posted April 23, 2016 @esaj If I was to lean the wheel against something while I was calibrating it, it would then think that the angle that I was leaning it at to be true up. Therefore, it should be as simple as recalibrating it at the new angle. For me trying to wrap my head around yaw / roll / pitch is making my head hurt. And I've played Kerbal Space Program; I should know this. As far as battery packs go, if I buy them from Chen, then I'm probably not going to need to synchronize the voltage, as they would already be in sync. Or at least I presume that they would be. I will try asking him. @Keith I'm thinking that the packs will be designed to go with each other, and that the converging / splitting cables will be included, but I will check with Chen to be certain about this. Link to comment Share on other sites More sharing options...
esaj Posted April 24, 2016 Share Posted April 24, 2016 1 hour ago, WakefulTraveller said: @esaj If I was to lean the wheel against something while I was calibrating it, it would then think that the angle that I was leaning it at to be true up. Therefore, it should be as simple as recalibrating it at the new angle. Trying to wrap my head around yaw / roll / pitch is making my head hurt. And I've played Kerbal Space Program; I should know this. I've played around a bit with the MPU-6050 (a 6-axis gyroscope/accelerometer chip) that many wheels use. Depending how the programming is made, it could be hard-coded to use rotational value around a specific "local" axis as "global" pitch and another as roll (it can also measure yaw, but I doubt it's used for anything in the wheels, as it doesn't have a compass, so it doesn't know true north). If you had background in (3d) game programming, you'd already know stuff like euler angles and cartesian system, quaternions, and the difference between "local" and "global" axes/coordinates, and whatnot, but as you probably don't, I'll try to explain up how the rotation of the board/gyro to another position will affect with an example: You are now the gyroscope There are three rotational axes around you: pitch, meaning your lean forward and back, ie. the rotation around the axis that passes through you from left to right (or right to left, depending whether we'd be using left- or right-handed coordinate system, but it doesn't really matter here), usually denoted as X-axis. Another axis is your lean from side to side, rotation around an axis that passes through you from back to front (or front to back...), that's roll, usually denoted as Z-axis. The last axis is the yaw, your rotation around an axis that passes through you from down to upwards (or from up to downwards), that would mean you turning in place (left or right), Y-axis. These are you local axes. The thing is, these axes turn with you. Basically your rotation around your own axes won't change when you lean back/forth/left/right or turn around, because the axes move with you (the red axes in the animation): Then there are global axes, like the blue axes in above animation. The directions are still the same: x goes from left to right, y goes down/up and z goes depth-wise front and back, but these are "fixed", ie. they don't move with you. If the ball in the above animation was your head, it could be like you'd turn your head left first, then look upwards, and then turn it more. For real world, we could denote the global axes like this: Do note that the blue axes in the earlier animation do not turn, ie. if global "up" is thought as "against the gravity", global "up" is still up even if you were laying on your back on floor. And of course which way really (globally) is "up" is very important in controlling the balance of the wheel. But when you lay on your back on the floor, your local "up" axis is now pointing sideways in relation to the global axes (ie. along the surface of the floor). Your "up" is no longer the same as the global "up". If you turn around your local up-axis, meaning to your left or right, in global coordinates, you're turning around x- or z-axis (or some vector along them). Ok, so if that made any sense, here's the deal: The gyroscope tells the changes in rotation (and acceleration) around its local axes. Depending how the chip is rotated (ie. how the main board is rotated, as it's fixed to that), the global ("real world") pitch could be reported as rotation around X, or Y or Z. For my self-balancing robot, I placed the chip flat on the robot, then I checked which axis changed in value when I tilted the robot back and forth, and used that, so it was lined with the global axis that runs sideways through the robot. But if I now go, and turn the chip on it's side, around the z-axis (running through the robot's back and front), that axis I'm reading no longer tells me the robots back and forward lean, but actually the yaw (sideways turning!) of the robot! Of course my software won't know that, it will try to balance the robot according to the values it gets from that axis I've picked at programming time, and will fall over! But, there might be a way to handle this: if the accelerometer of the chip can detect gravitational acceleration, it should be (maybe?) possible to pick the correct axis matching global up, and then during calibration, determine which of the remaining axes tells the pitch and which is roll. Maybe Quote As far as battery packs go, if I buy them from Chen, then I'm probably not going to need to synchronize the voltage, as they would already be in sync. Or at least I presume that they would be. I will try asking him. The packs can go "out of sync" through self-discharge when they are not connected together. Best to check with a multimeter beforehand. The "easy" way to get them "synced" (around same voltage) is to charge both battery packs to full before connecting, then they should both be at full voltage (but best still to check with a multimeter before connecting). Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted April 24, 2016 Share Posted April 24, 2016 Maybe try unscrewing the motherboard from the case and orientate it the way you plan to have it mounted (if there's enough cable slack) next to the case, and try calibrating it in that position first before doing much more? Be cautious to somehow prop it up carefully to avoid shorting anything out and avoid the need to touch the motherboard while doing so. Perhaps taping it to a box next to the wheel that is supported by two tables on each side would work? From the calibration videos I've seen the wheel should be able to roll freely while the chassis is kept level. Link to comment Share on other sites More sharing options...
WakefulTraveller Posted April 24, 2016 Author Share Posted April 24, 2016 @esaj Are you trying to make my head hurt? Okay. So in all seriousness. I know that the X and the Y (like in the image below) can be calibrated at the same time. The Z as far as I can tell can't be calibrated and doesn't have any need to be. It's likely fixed. The forward and a backward, which would be the right and left side of the board respectively, won't change when I move it. So no problem there. I'm trying to wrap my head around what would happen if the board was rotated 180 degrees on its Y axis and then recalibrated. Would leaning forward then make it go backwards? By your logic with the batteries... wouldn't they just go out of sync again if not charged for a while? Plus, I don't really see why it matters all that much. I imagine that they would self correct eventually. Link to comment Share on other sites More sharing options...
esaj Posted April 24, 2016 Share Posted April 24, 2016 21 minutes ago, WakefulTraveller said: @esaj Are you trying to make my head hurt? Okay. So in all seriousness. I know that the X and the Y (like in the image below) can be calibrated at the same time. The Z as far as I can tell can't be calibrated and doesn't have any need to be. If it could, it would be calibrated relative to the other two axes. So no problem there. The forward and a backward, which would be the right and left side of the board respectively, won't change when I move it. It's the rotation around Y-axis (yaw, the orangeish arrow turning around the character, that's rotation about the up-down = Y -axis) that doesn't matter, the Z there means that the red axis pointing through (back to front) the character is Z-axis (and the rotation around that is the bluish arrow). The problem is that if that character were the gyro, and in the current position of the mainboard (assuming it's "on its side" inside the other battery compartment), the real pitch of the wheel would be denoted by the rotation around the sideways axis (X), which I assume you mean with "Y" (tilting forward and backward). If you now turn the mainboard, and thus, the gyro to "flat" position, what happens is that the character would now be sideways. The local X-axis running through the sides of the character is now pointing up in global coordinates. So the "up"-axis of the wheel is now the "sideways" axis of the gyro. The firmware-program still reads the rotation around that axis, thinking it's the forward/backward lean of the wheel (pitch), when in reality it's the turning around the wheels Y-axis (yaw), and the real pitch of the wheel is now rotation around the characters Y-axis (what the program would think as yaw, and probably doesn't read at all). So it would try to balance "around the wrong axis" and would probably seem to behave very weirdly. I'm a bit tired (it's around 4AM here ), I might not make much sense right now. Quote By your logic with the batteries... wouldn't they just go out of sync again if not charged for a while? Plus, I don't really see why it matters all that much. I imagine that they would self correct eventually. After they're connected together (and have reached the same voltage), they will keep the same voltage until they're disconnected. They will start "self-correcting" when you connect them together, the problem is, the "correction" may be very violent if the voltage level is very different, as the difference and internal resistances will define how much current is passing between the packs. See here for more technical details: Link to comment Share on other sites More sharing options...
WakefulTraveller Posted April 24, 2016 Author Share Posted April 24, 2016 @esaj I updated my last post with with how I think it works, or at least what would make sense. So the Z axis is likely fixed relative to the board itself and is only used for giving the unicycle a forward and a backward. When I move the board up I'm only going to be altering the X and Y axes. The Z axis will stay the same. Therefore leaning forward will still move it forward and so forth. The X and Y can be recalibrated. Also, how are the battery packs connected to each other exactly? Is it through the board or the cables? And what are you doing up so late / early? Link to comment Share on other sites More sharing options...
US69 Posted April 24, 2016 Share Posted April 24, 2016 To say it an easy -hopefully understandable-way: some Boards Are only for horizontal installing/operation some Boards Are only for Vertical installing/Operation! And if You have a Board like that: no recalibration in the world will Ever Change that!!! Thats what The People here Are tryin to say this Wheel Is also Sold by The "godfather" of Batterie upgrading: 1radwerkstatt, WHO always gives You The option of upgrade....!!!but!!! there Is One big sentence on The selling Website for this MCM3: attention!: for this Wheel no other Batterie configurations possible!!! i already Said that on an other Thread before, that Perhaps You Are stuck to Change Your 260wh to a better Batteries with 414wh, because of that!I and thats all You can Do.... so i Go with everything what @Keith has Said..... Link to comment Share on other sites More sharing options...
OliverH Posted April 24, 2016 Share Posted April 24, 2016 If I remeber right from the EM Microworks board 30B which is in parts similar to the Gotway Board. There's no reoriantation jumper/ bridge like on the the old 18 k/h boards. On this you can change the portrait to the wide orientation. So I think Gotway has a tweaked Fimware for the MCM2s 680 Wh. You can only desolder the MPU and put it in an other orientation (never do this, it's only a theoretical option). Buying a new PCB and 2 new battery packs would not make sense from a financial point of view. Sell the wheel and buy an other one. The first wheel is the entry and than you know your requirements. Happened to me also. Link to comment Share on other sites More sharing options...
jer Posted April 24, 2016 Share Posted April 24, 2016 I would charge it at work. No need to change anything. Another way is I am quite fat and can quite a reasonible range, by not rinsing the power at the beginning of journey. This applies to all EV's including those formula E ones. I know this is boring way to travel, but I expect even Tesla owners have to do this. Ironically it become the challenge to get from A to B with using not too much power. 3rd Can 1radwerstatt send by sea? Link to comment Share on other sites More sharing options...
Chriull Posted April 24, 2016 Share Posted April 24, 2016 5 minutes ago, jer said: ... Can 1radwerstatt send by sea? I would assume that shipment from Germany to UK should not impose any problems - but the best is to ask them directly. @1RadWerkstattis a member here or can be reached via Facebook, email or telephone. Link to comment Share on other sites More sharing options...
jer Posted April 24, 2016 Share Posted April 24, 2016 No problem for me getting them in the UK, we are still in the EU. Jer Link to comment Share on other sites More sharing options...
SlowMo Posted April 24, 2016 Share Posted April 24, 2016 Like what @OliverH have said, it would be very expensive to buy a separate battery pack + motherboard. Advises were given in another thread to buy the biggest capacity battery or at least 340wh but were ignored. Link to comment Share on other sites More sharing options...
esaj Posted April 24, 2016 Share Posted April 24, 2016 8 hours ago, WakefulTraveller said: @esaj I updated my last post with with how I think it works, or at least what would make sense. So the Z axis is likely fixed relative to the board itself and is only used for giving the unicycle a forward and a backward. When I move the board up I'm only going to be altering the X and Y axes. The Z axis will stay the same. Therefore leaning forward will still move it forward and so forth. The X and Y can be recalibrated. Try what @HunkaHunkaBurningLove suggested and see if the calibration works when the board is in another angle. Just trying to prevent you from losing your money, in case it doesn't work. 8 hours ago, WakefulTraveller said: Also, how are the battery packs connected to each other exactly? Is it through the board or the cables? Usually through the cables, the mainboard typically has only one battery input cables. Something like that, check if the connector comes with the packs, and if not, check what type of connectors the packs use and solder one yourself or order from Aliexpress, or Amazon or whatever. Search for "<connector-type> y-connector", the above for example is "XT60 y-connector". 8 hours ago, WakefulTraveller said: And what are you doing up so late / early? I'm a bit of a night person Link to comment Share on other sites More sharing options...
Keith Posted April 24, 2016 Share Posted April 24, 2016 1 hour ago, esaj said: Try what @HunkaHunkaBurningLove suggested and see if the calibration works when the board is in another angle. Just trying to prevent you from losing your money, in case it doesn't work. It really isn't necessary to physically move the main board to test if recalibration will work. Simply lay the wheel on its side so the main board is in the same orientation as it would be if fitted in the top. Recalibrate the wheel and, leaving it on its side lift the rear casing a little, the wheel should spin forwards, lift the front casing a little it should stop and spin backwards. If the wheel is lifted to its normal riding position it should beep and shut down in the same way as if it had fallen over. Don't forget to recalibrate again with the wheel upright so you can actually use it still as it is. like @KingSong69 is saying, if @1RadWerkstatt, are saying this wheel cannot be upgraded then I do not believe simple recalibration will make the main board change orientation. However, at least this way you can test the theory without dismantling the wheel. Link to comment Share on other sites More sharing options...
US69 Posted April 24, 2016 Share Posted April 24, 2016 @Keith i Just Said that 1radwerkstatt Is Not giving Upgrade options....what Is a "Fingertipp" that it's not possible or Even hard at all to Do so....it also Is possible they don't give The Option because they don't want to Mess Around with moving The Board ... which Is Quit a Hard Tasks ....if You Are no Gotway engineer.... i would prefer to buy another Wheel before moving/Messing with The Board....but Not my choice Link to comment Share on other sites More sharing options...
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