 Hello, yeah. This is a sort of state of play of a project I'm working on for building my own electric motorcycle because I've built various other motorcycles and now moved on to something electric. It's using the methods and systems that an online group called Open Inverser Dodge and their forum have been generated which takes a slightly different approach to hacking the components of electric vehicles and hybrid parts. I almost called this talk how I'm building a monstrous electric vehicle from hacked scrapping electric vehicle parts but my project was on motorcycle so that's what I chose as the as the topic. And with things like this is why as the the guy just said I built a diesel motorcycle in fact I built several diesel motorcycles four in total. One of them had a Volkswagen TDI Golf engine in it which was a turbo diesel bike and that worked really well and now I'm looking at moving on to something a bit more up to speed with current technology. I've also worked on many self-built electric vehicles. I used to work part-time or help a guy that sort of built and mended and converted cars and kick cars but that was I know whole numbers about 10 years ago and it was all lead acid batteries big DC motors and similar so it's very different to what's available now. I remember when I was doing that the very new cars on the on the game were the Prius and the Leaf and they're now very established vehicles. I also enjoy technical challenge I quite like that sort of thing the novelty the novelty of doing my own one. I put a question mark there because electric vehicles are no longer novel and I got cheap because it's cheaper than buying new again that's a relative thing because you've got your time and of course as I'll mention later on the batteries are there's no cheap way around that and economy of use and then right at the bottom the time is right and this is because electric vehicles and hybrids especially are being around long enough that they're now in the breakers they're being broken there's nothing special about the parts which makes them cheap and especially the Prius which is why I'm going to focus on you can pick up parts of those that the prices are just not special at all it's it's quite good so the time is right for that and I'll go over briefly in this presentation about the main components being the motor the battery briefly about battery management I'm not going to go into that in detail the inverter or the power controller used for controlling the motor charging and then I was gonna have a section on chassis and wheels but decided I couldn't really get into half an hour and besides the project really hasn't got that far so that the rest of the presentation is mostly going to be on how I'm going to do it rather than my previous presentations which would blow by blow stage of assembly to get over mechanical issues so I'll start with things in a different order than my list so I'll start with a battery so looking at existing electric vehicles I've just picked two at random being the zero which is a sports bike and the Harley Davidson live wire which is more of a cruiser just from ballpark look at how far you go and the one has a 14.4 kilowatt hour battery in it and the other one has a 15.5 kilowatt hour battery in it and the one has a range depending on how fast you go which is wind resistance and the start of riding is between 112 and 156 so these are the sales quotes and the Harley of 110 to 146 so you know you've got about between a hundred and about 150 miles out of those two which gives you an idea of how many watts or what hours in energy per mile they're doing and from that you can back calculate and say well I'm building a similar vehicle with similar aerodynamics and a similar size with you know it's a similar chassis arrangement compared to a car so I'm going to get a similar power requirement than these which helps it's very difficult to work these things out in advance with any great technical accuracy you can buy new batteries but what I'm looking at is what's in the breakers what can you buy and as I've mentioned the hybrids and the electric vehicles in the breakers and unless you know what you're doing these these are quite weird things there's a lot of places that still terribly frightened they're terrified of being electrocuted which is a potential problem but most of the batteries is when you cut the main 12 volt supply to it because all electric vehicles and hybrids have a 12 volt battery for running the lights and the radio and all the other systems as a conventional car with the same voltage range of a 12 volt battery once you cut that internally to the large traction battery there's contactors which isolate it so unless those isolators have malfunctioned you take the 12 volt battery off an electric car and the battery is safe to handle as a battery I mean when you take the lid off that's that's a different matter the technology of batteries is is as we all know it's all lithium a majority prismatic or rectangular cells in the electric cars I believe there's only one manufacturer I can think of that still uses cylindrical cells that's you know a choice I don't know why everyone uses rectangular cells and then and then another another company still is round ones I've I've not looked into the technical details enough to know why that's chosen but when looking at buying batteries it's it's a risky market because you don't know if you're buying a dead one or a good one or you know you take the case out and it's full of bricks it's it's it's you've got to do a bit of homework and trust the person you're buying it from or turn up with multi meters and tools you can't just put a multi meter on an electric vehicle battery you have to take the lid off and measure the cells there's a variant on that but I'll come to that later on so so the cost of the batteries I I spent a lot of time surfing eBay and online suppliers for for a second-hand battery and it was very difficult to say is it a good deal is it not until I realized that if you look at the cost of the stored energy rather than the absolute cost of a battery pack so gone into there we go gone into screen save mode let's come back so if you look at the battery of kilowatt hours is the actual energy storage divided by the cost of the actual battery and end up with kilowatt hours sorry price per kilowatt hour and a low good price is is 120 pounds per kilowatt hour if you just generally go looking and they go up and up and up to 300 pounds kilowatt hour even more so some people ask ridiculous prices because they still think that electric vehicle parts are really special and people still pay the money and the other thing is when looking for batteries is the known brands are always the favourites when people say all let's buy a let's buy an attraction battery from electric vehicle for running a project whether it be motorcycle or hacky racer or something they go oh yes lose the leaf we've heard of the leaf and someone else says no let's use the Tesla battery because they've heard of the Tesla and they've seen the the media propaganda that says they're the best in the world and then they ignore the fact that there's there's now dozens of electric vehicles and hybrids and these stop-start cars have nice 48 volt batteries lithium batteries that are quite high discharge rate the price of those hasn't dropped yet so you could kind of think out the box a bit and just look at them as as cells rather than branded parts so what I chose was a BMW i3 battery and there it is outside of its enclosure each one of those eight modules weighs I think it's 20 kilos which is quite high but not ridiculous compared to the the big turbo diesel motorcycle I bought when you think about the whole weight of the vehicle and for scale there's a pair of gloves and the actual motor there will all laid out as it was beginning of the or this was about a month before the pandemic hit and and I was all keen to work on it and then the pandemic hit and and I had all the time in the world but very limited income so basically the project has been on hold until this spring again because I couldn't afford to invest in it anymore but anyway it's a 96 cell battery 94 amp hours it's 33 kilowatt hours of of power and it's in 12 so eight 12 cell modules which module is is 20 48 volts and the other interesting thing whether I cover it now or later on is each of those modules has its own battery management system attached to it and then they're daisy chained around the the pack and then when I come on to talk about battery management in a moment people have reverse engineered the protocols so you don't have to put your own battery management system on it you can use the existing one and then use the hack to know now not open source but reverse engineered codes for for for then integrating that into your own system that one of the common things people say when I say I'm thinking about building an electric vehicle they say oh no they say the battery life what are you going to do when the battery runs out but there's been laboratory tests on on these particular cells and and those tests have either been published or found and put up and these cells are rated at 4,600 cycles in average usage but but 100 depth of discharge which is the worst case it puts the most stress on the cells going from completely fully charged to completely empty so that's 600 cycles until it's 80% depleted in usefulness at which point it's considered end of life even though it still would have a huge life after that and the i3 that the battery came from could do a quoted 125 miles per full charge and if you multiply those together you get an expected life of 575,000 miles which is way in excess of the average life of most vehicles these days within the original battery pack there was a very simple heating to prevent frost and and then there was quite a complex HVAC air conditioning type chiller in there to stop the batteries from getting too hot this is incredibly difficult to reproduce especially on a small vehicle like a motorcycle so I'm going down the path saying the UK is not an extreme climate we're not a desert we're not the Arctic it's kind of damp and horrible the whole time especially today and I'm not really expecting the the very narrow operating zone to be exceeded in normal use and if it does I can just avoid the the extreme power that they can't supply and I'll avoid rapid charging in those conditions which shouldn't be too too difficult to do and too much of a hindrance the I say the project is largely uncomplete but these are the batteries stacked up and I've got six in two rows of three with the other two on top which forms like a low rectangular format so I'm going to be building a battery box around those and then building a girder frame around around the battery box just behind it you can see the motor and then I've got a wheel on there pretending to be a seat just trying to lay things out I've covered this one I was looking at the battery so most battery packs have the built-in battery management systems it's been hacked the other interesting thing is quite recently there's a company called Zephyr is an Australian company and they've been making battery management systems for large electric vehicles which is quite special you can't use the sort of thing you'd use on a model the radio controlled model because you're talking voltages three four hundred volts as nominal and it has to be isolated and everything else and and this company made battery management systems for kit builders and they've been doing it for 14 years I think they're quite respected and the reason I mentioned them here is they went out of business last autumn which is not the sort of thing you want to announce but they've kept their website open they put a little bit of blurb in there and they've kept their catalogue and everything open but instead of clicking on the the byte now cart it links to a zip file and in the zip file you get circuit diagrams girber source code the hex file to upload straight to the the the micro and they even got stl's for 3d printing your own cases and enclosures which I thought was an amazing gesture from a company who decided not to operate anymore and the motor again there's many motors available I've chosen a Mitsubishi Outlander motor which is the one pictured but there's there's other ones like Leafs Prius the Lexus rear motor which is a transacres like this the Outlander which Outlander which is this which is a is a motor gearbox I don't know if you can see on there you got the motor on one side and then the gearbox and then and then there's the two ports you can't see because they're side on that the axles will go straight out to the wheels so you know if you were converting a car you'd put one of these where the engine was connect your shafts up and and that that would be your drive system it's very simple and and of course everyone loves a Tesla so I put those in there as well and basically any EV or hybrid has the motor in it they're all much the same they're all embedded permanent magnet motors I'll just have a quick picture of that in a minute and the commutation is determined by something called a resolver at the end of the motor that measures the absolute shaft position for generating the rotating magnetic field for things like field oriented control motor control for those that don't know what an embedded permanent magnet motor is is on the left you've got a conventional motor with the magnets around the outside of it and then on an embedded permanent magnet motor the magnets are embedded within the iron core obviously a laminated core and that I think allows it to spin a lot faster because they're locked within a steel in clay steel cage and it also allows the motor to act as a permanent magnet motor as well as a certain motors as a various induction motor as well the the resolver so I don't want to go over time is looks complex it's this weird looking thing on the left and what that is is a inductively coupled position sensor and in the middle there's three coils what you energize one coil and then as the magnets the not the magnets of the motor but a second pickup magnet or is it core iron core sorry it's an iron core so inductively coupled as that rotates you get different peaks that are 90 degrees out of phase on the other two coils and and when you resolve those two add them up you get the shaft position and that's an instantaneous non-contact very durable device it's it's made of coils of bar and bits of steel that's not going to go wrong you hope and again the reason I mentioned that is almost every electric vehicle has one in as part of the motor and normally there would be a very expensive dedicated chip that performs this this function of energizing the coil and then getting the shaft position out but the guys in the open inverter forum have worked out that you can energize it with the output from a microprocessor such as an stm32 which is their choice with an op amp buffer and then you can read the inputs with an analog input and do the job in software so you know that costs a couple of pounds worth of components and is easy the the the motor I've chosen again is the outlander motor it's a 70 kilowatt maximum peak it's got 195 newton meters of torque which is monstrous and it weighs 40 kilos which is chunky but not out of this world and you can get them in scrap price two to four hundred pounds relatively regularly obviously there's idiots out there who want ten times that much but you know if you if you get a real breaker who's got actual stock turnover they're selling them a lot lower and there's people at record you can get you know sort of 50 percent more on top of those figures for very short durations so that's that should be quite exciting how I solve my transmission problems is is on on the left hand side is the motor on the right hand side there is is the is the gearbox I've chosen and I've chosen the BMW motorbike gearbox because it fits the format of what I'm doing and I've made a coupling using the insides of two clutches one clutch from the original gearbox and the other clutch plate was found by by members of the opening inverter community who found a clutch that fitted the spline output of the motor because if you've ever walked into an engineering workshop and so I want a coupler made with a couple of slides on it splines on it it gets quite expensive and then when you say it's automotive they get disinterested and go oh no there's another loon coming to our workshop but I made this up for the cost of two clutch plates a lump of aluminium and an evening on a lathe building up a central buster bolt the two halves to and then I simply cut off the outside with a with a grinder I then made two flange plates with some cardboard aided design which is about the level I work out I should learn some proper CAD but I'd never get around to it but I like this method anyway and that's my transmission unit assembled and and ready to go which I think is quite neat the thing I had to do that was quite technical is get the two shafts aligned because if they're out of alignment you get a lot of wear on on the clutch blinds which I've seen as I mentioned in the previous life when I was helping a guy mend and repair a homegrown conversion so so that was that was it but the thing that the whole presentation kind of hinges round is the inverter and there's many choices because many electric vehicles have inverters I've got a list there of some I've chosen the price for various reasons partly because they're very cheap the scrap price is about 200 pounds the is it or is there there's the other hybrid that that toyota do that's less less sort of us so you can get an almost identical inverter for about 100 pounds and the approach the open inverter for me using is is they've realized that the inverters are in three distinct layers you've got the power components these are the high voltage high current transistors the power components the iGBTs and they'll be smoothing capacity as well then there's the middle layer which is the power power components control which has very fast switching edges to get very very little losses in in your iGBTs the overload protection so it doesn't explode you got shoot through protection because I'll explain that on the next slide the it has to have you know it has to be controlled from low voltage which is you should we say the car side controlled in the high voltage side and you need good isolation from that because you can't have 400 volts flows floating around a vehicle and then on the top I've referred this to as the brain bits and that's there to communicate with the rest of the vehicle it's there for reading the motor resolver for the shaft position which is is important functional part and it's for producing the switching sequences on the output that result in the rotating magnetic field and motor spin um to speed up a bit the so so this is a schematic of the the should we say the power side it's it's very simplified but you can see there's two the two grain gray modules are two three phase power stages for in the price it has a two motors it has a motor g motor generator one and a motor generator two and they spin in opposition to generate all the motor forward and reverse um movement that's that's a subject in itself but you get those and then on on the the left in the yellow part you've got a a boost buck controller and that converts the battery voltage into the high voltage bus uh so so that can so the battery is about normally 250 volts the bus voltage can go up to over 600 volts not that ever goes there much but we've got this device within it and if you flip take it apart and flip it over you you've presented with this the big shiny thing on the right hand side of the the right photo is the inductor for that power converter and on the left hand side is the um 12 volt or 14 volt uh DC to DC converter for running the rest of the vehicle the lights the heat of the radio heated seats and and you know you know all the other stuff like that um and and that's quite capable that's that's like 120 amps of 14 volts uh so it's a very useful bit of kit but when I joined the open inverter forum everyone was saying oh no they're saying if I connect this to my diy battery um it doesn't work because it's not within the price battery range of 80 to 235 volts therefore we can't use it and and there was all manner of talk about that so what I did and and this is my input to the open source world in in here and I'm it's all rather proud of it is I reverse engineered the input stage of this DC to DC converter and um worked out you could change the feedback resistors um and then you could get it to cut out at the voltage you wanted it to and I also looked at the spec of the components of that that part and realize that that the input to that can go as high as the high voltage bus so you can you can connect it to your four whole 400 volt battery and that's fine um and the actual hack is how how do we make it work for us uh we've got all these protocols going on and all these electric cars and and uh to reverse engineer that is it's both tedious and difficult and it's proprietary knowledge so you won't ever know if you've got it right so the open inverter approach is to remove the brain part that I just spoke about is to just take that out to say right we're not going to use that we're going to use our own one and pour our own one in and within the prius converter because that particular one has got the distinct layers that are in distinct circuit boards is you can pull one out and put your own one in and on the right hand side that is a a board that's produced by one of the guys on on the open inverter form you can get all the firmware for it and design files but he also sells them as well so you can buy that as a as a as an off the shelf thing take your prius converter apart unplug a circuit board plug that one back in put the lid on and it's yours you you connect to your battery management system uh control signals your your throttle your brake pedal um and and a few other things and and off it will go it's also wi-fi enabled so you configure it via a web page on on your laptop um it's briefly cover charging so I'm running out of time um I want an option on charging uh the ones available are ac charging which is type two or the socket in your house ccs dc charging or she demo dc charging which is falling out of favor one way is to use a pre-built module out of a leaf or an outlander and I believe the controller those the control codes for those the canvas signals are known so you can make those work yourself um but going back to that that schematic I just put up if you look at this buck boost converter in itself that can have 250 volts on one end and 600 volts on the other so there is the the potential to use that to charge your battery straight off the mains um obviously it's a non-isolated charger so you have to be careful with your insulation which you should be being careful with um yourself and commercial views uh sorry the the other one is to use the motor as an inductor in a voltage converter using the the main car inverter which is something the the zoe uses I think which is why when you hear a zoe when it or see see a zoe parked up and charging it's quite noisy because it's using the motor as a uh an inductor and and and and that's obviously uh producing some sound uh the again coming back to the opening inverter forum is the other way of doing it is to use an existing module to use an existing module and and and they've they've picked for various reasons the bmw lim module which is a local integration module and and that controls the protocol to the ccs charger which is a roadside charger and um and the the lim module takes very simple or comparatively simple can bus signals from the main car controller and then this lim module converts it into the incredibly complicated multi-layered multi-layered of abstraction into the ccs charger and we can control that um I I was going to talk about steering but I've I've run out of time um smaller things I was chatting chatting to the hacky versus hacky racers earlier so I put some smaller converters up so I got honda rime converter bmw i3 i3 um charger inverter because the i3 has a range extender engine in it and and then I've put up a kia 10 kilowatt motor alternator which is again it's not an alternator as you'd imagine it it's a three-phase motor with a resolver on it and and then the power control is done by an inverter which is the one on the extreme right my closing notes are I shouldn't have to say this but because there's been a vocalization of this on the upper inverter forum is the developers are not your your support line don't contact them well not don't contact them their inboxes are full they're fed up so they would rather and they voice this themselves which is why I'm repeating it they'd rather he went on the forums because the forums are very active I mean this is not a drop-in solution so there's work it works but it's a working process and lastly there should be a page of resources so if you want to follow any of this up you can so that concludes my presentation I've got some stickers I want to give out afterwards I'll be outside for but thank you very much