AGENDA Introductions by new attendees What’s new in the EV world Thoughts on Caterham’s plans for EV Seven Conversions AOB ATTENDEES: John, Mac, Ian, Simon, Dan, John, Jonathan, Stuart, Martin (new) INTRO’S BY NEW ATTENDEES MartinNon-practicing engineer Built 420R about a year ago Work in sustainability field running own company for 9-10 years Racing driver. Used to race R400s. Endurance and prototype races including Le Man 24 twice New project We then spend about 40 minutes talking about Martin's project which he would like not to be minuted. If you'd like to find out more about Martin's project then you can join the meetings :-) Other Discussion Points McMurtry Speirling video on Carwow.
Caterham / Webinar EV question:A different question was asked this time. Previously the question was when should Caterham do an EV whereas this time we asked when Caterham should do an electric Seven. People were less enthusiastic about an electric Seven. EV Vehicle Financing and costs:EV's are getting much more expensive and some on the call have decided they'll need to do an ICE car again next time as EV's are not cost effective. Ford announced a $20k car. [ after the call a link posted to WhatsApp about how Ford has agreed to use the VW MEB platform for its cars to be built in Europe]
The other side of this is that manufacturers are going to be forced to sell certain volumes of cars that are "eco" and so can't just have expensive EVs that don't sell. Motorway charging stations now asking for 79p/kWh. Under the radar Seven EV conversionJM had a video call with him last week Saw pictures of very good progress 5 battery boxes - front engine bay, fuel tank, boot, etc Custom built motor Field weakening being used Cost of components has gone up, some almost doubled Discussion about field weakening, where signal processors create a rotating field to produce torque but also a static field that opposes the stator static magnets and so reduces their field. One of the problems with this is that under certain circumstances the permanent magnets can get demagnetized and become less effective. JM is writing another LF article, hopefully for Feb'23, about the different components of an EV Steering Column and packaging issuesOne of the problems with a Seven conversion is that the steering column gets in the way of where you'd like to put more batteries Stuart recounted how Club members in his area had taken over the conversion of a Seven to include a V6 (?) engine and where they had to re-route the steering column over the top of the engine to a transfer box and then down to a rotated steering rack. He thought the solution worked well for them. Rack can be rotated to take a vertical input. Transfer box could possibly be attached to the battery box so the chassis doesn't need anything welded to it. JM will contact them. JM said his current thoughts are to make a single rectangular front battery box but to have holes cut in the front and back where the steering column would naturally run. Then weld a pipe between the two battery box holes that the steering column runs through. This would mean only one box is required and reduce the need for extra metalwork and cabling between the boxes. Martin asked if a steering column could be added after a battery box is installed but Mac pointed out that you could include the steering column when the battery box is outside the car and then that whole assembly could in installed and the two ends of the steering column can be connected after install. Jonathan asked if mechanical linkages are a requirement under UK law. Nobody seemed to know. We had a discussion about removing some chassis members for better battery access... but JM nervous about chassis changes and DVLA Mac asked how we're going to get the battery and motor in if we can't change the chassis. JM said he was planning to create a sub-frame off the engine and gearbox mounts. We had a discussion about software updatesPoint made that VW software updates are very slow On the flip of that, Tesla updates can be infuriatingly frequent - you can get into the car in the morning and find all the controls have moved General view that Tesla has too few physical controls/stalks. Jonathan asked if there are any thoughts on "regular" EVsGeneral view that Tesla still has the best charging network and in-car software that supports it View that EVs are also too highly spec'ed and therefore increases cost of what is already expensive offering Meeting closed at 21:20 Other Links After the call a few links were shared on WhatsApp BMW's e-ink covered car: https://youtu.be/r8wUIoyN_TA List of EV's coming in 2023:
AGENDA Introductions by new attendees What’s new in the EV world Thoughts on Caterham’s plans for EV Seven Conversions AOB ATTENDEES: John, Mac, Ian, Paul, Simon (new), Dan, Andrew, John (new), Jonathan Apologies: Stu INTRO’S BY NEW ATTENDEES JohnOwns a '95 HPC and MG5 EV estate Retired IT management Has completed IMI EV maintenance course Looked (looking) at setting up in business as EV specialist but unsure of economics at the moment SimonDay job is physics teacher Also club membership sec and gen sec REMEMBER: there's a reasonably active WhatsApp group that accompanies this SIG. Contact JM on ev@caterhamlotus7.club if you want to join that or this SIG.
WHAT’S NEW IN THE EV WORLD Not really discussed THOUGHTS ON CATERHAM’S PLANS We had a fairly lengthy discussion about the comments made by Bob Laishley, Simon Lambert and David Ridley on the "An Evening with Caterham Cars" held on the previous evening (2022-12-12). Here's some of the discussion: Bob said that any EV has to conform to the Caterham ethos (from the captioned transcript of the webinar): We discussed the fact that power supplies to the circuits are going to be a challenge (there's been a BlatChat thread about this too). And if you had 15 EV's all finishing a track session at the same time and wanting to charge at 150kW then the circuit would need a 2MW connection just for the charging. And it would only be used a few times a day for a few days a week (at best). The track's economics of this are a challenge and the resulting cost per kWh might be a little eye watering. Also discussed whether tracks could have large battery banks that mean lower supply to the circuit that can be charged over a 24 hour period and therefore not need instantaneous 2MW - certainly possible, but also expensive. Though perhaps such a battery could be "trucked" in for special EV meets - espeically as this EV track day industry builds. JM metioned that MSUK has recently announced an EV race series (possibly for 2023?)Bob mentioned that a design consultancy had been commissioned to create some visualisations of what a non-Seven Caterham EV might look like Simon mentioned that CC have an IRS test car that they've worked on. We had a long-ish conversation about drag and the spreadsheet created by JM and shared on the EV WhatsApp (see below). The calculations are eerily close to what top speeds you might expect from a Seven. The frontal area and Cd figures used are guessed but seem to hold up and make the numbers work. SEVEN CONVERSIONS For newcomers JM mentioned there are a few EV conversion projects already underway. Sheffield Uni's AMRC is on their second iteration of their EV (and we're hoping their project manger to join us for one meeting), a French race training company has a couple of converted Sevens, there are a few Westfield conversions out there. JM is also aware of someone who wants to remain anonymous but is a long way through a conversion. Lots of chat about motor placement options Discussion about whether Seven EV is currently better suited as a hillclimb/sprint vehicle using a smaller battery and/or capacitor store. Led to a discussion about EVs holding records at events like Festival of Speed and McMurtry's fan assisted downforce car. Paul asked if JM had had any more thoughts about hub mounted motors. Led to a discussion about Axial Flux motors from the likes of Yasa and Equipmake etc. Axial Flux motors have higher torque and potentially reach their best efficiency at lower RPM. JM mentioned that a Seven needs to achieve about 1800 RPM at the wheel to do 120mph (will vary depending on tyres/wheels etc). Making Axial Flux viable candidates for with hub mount or for a twin motor install where a diff would sit - needs linked motor controllers that take account of different wheel speeds when cornering and can provide LSD functionality. Discussion about gearing of a conversion. Motors (especially radial flux motors) tend to run most efficiently at 10,000+ RPM and so need gear reduction to get down to 1800-2000 RPM needed at the wheel. Discussed relative merits of gear reduction at the motor, using existing gearbox (locked in one gear), diff gear reduction etc. Mac mentioned that it can be a challenge (and those attending the meeting know where Mac gets his data points from) to have a gearbox in the drive train and to use multiple gears. They tried it for a long time and couldn't get it to work. The main problem being the different intertia characteristics of an electric motor vs an ICE. You need a way of changing a motors speed to match the next gear ratio and having a smooth transition very quickly or put up with a slow gear change. There's probably a lot more that I've forgotten or didn't make notes on. Please let me know if you attended and would like to have this post updated. As mentioned above, here's a screen shot of the spreadsheet that calculates power needed to overcome drag at a given speed. If you'd like the source spreadsheet then please contact me.
The fairly simple math came form here. The figures for frontal area and Cd are guesses but seem to make sense from other discussions on these forums. JM
October 2022 EV SIG Meeting Agenda Introductions by new attendees What’s new in the EV world Thoughts on Caterham’s plans for EV Seven Conversions AOB Attendees John Dan Garry Jonathan Stuart Andrew People Introductions John Martin - Electronics Graduate 35 years doing software and hardware product development 30 years own company EV ID3 5kW solar and Tesla battery Dan Healthcare professional Recently bought R500 Interested in where EVs are going Jonathan 1800K built 20 years ago Collecting every known 7 wiring diagram and these are new wiring diagrams What would chapman be producing now Torque vectoring, tuning Heat recovering Garry Teenage years working on cars Wiring dark art Built Caterham from kit 10 years ago House has solar Peugeot 2008 EV Tesla 3 on order Stu Car nut all life Tesla Model 3 for 2.5 years, 60k miles How far does it go on a charge is irrelevant Andrew Software back ground Looked at EV 25 years ago then gone off boil Driven electric karts which are more fun than ICE karts 25+ years since owning a 7 but looking to get one Other Seven Projects Netherlands ?? French driving school http://e-motors-academy.fr Sheffield Uni https://www.amrc.co.uk/news/return-of-the-mach JM relayed points from his discussion with Bob Laishley at Beaulieu Caterham could do what I’m proposing to do tomorrow (JM agreed) But Caterham needs to have a car that has at least some credibility on a track, no good as just a Sunday car as the first thing journalists would want to do is take it to a track. Then they’d report that it overheated and ran out of juice in 15 minutes. Therefore, CC are watching but waiting for battery technology to get to the point where there’s a viable Caterham offering Decided to go with following communications: Monthly meetings JM to put notes/minutes up on a CL7C Blog JM is blogging at Purplemeanie.co.uk JM will post to BC when there’s a new blog post on Purplemeanie.co.uk JM went through some of the draft of his design presentation for remaining 35 minutes.
Agenda Introductions by new attendees What’s new in the EV world Thoughts on Caterham’s plans for EV Seven Conversions AOB Attendees: John Mac Ian Paul Dan Andrew Stu Intro’s By New Attendees Mac Automotive industry and retired Lotus for 17 years Project manager for a big name EV car project for 4 years - Vice President of Vehicle integration Built a 140 Super Sport in 2012 Interested to see if decent EV can be made in such a small package Ian Mechanical engineering Retired now Passion for classic cars Has a Caterham CSR PV, solar heating, Powerwall (moved to new house) Model 3 now and i3. Has had a leaf etc Paul Mechanical engineer retired 1995 Caterham What’s New in the EV World Bob Laishley's interview in on Caterham's EV plans in Autorcar. General consensus seemed to be that Caterham are known for the Seven and must keep that going in some form. Range considered to be a problem as Sevens are often driven in remote places where the charging network isn’t very good JM reiterated conversation with BobL at Beaulieu Caterham could do EV tomorrow, but… Know that wouldn’t be good enough to have a car that lasted 15 minutes on a track and then overheated and took 2 hours to charge Will wait for technology that can deliver a true Caterham Zero-EV Merger. JM is hoping to meet with Zero-EV soon as they are local to Bristol Swindon Powertrain's announcement of their battery module Discussed the fact that this probably wouldn’t work well for many classics and certainly not 7s Mini conversion saga, here, and how it might affect sEVen projects DVLA are holding back some car’s V5s when the owner notifies them of an EV conversion. They are stating that any chassis changes need an IVA and that they are “radically altered vehicles” also meaning they get a Q-plate and cannot keep their age appropriate plate. This leads to the conclusion that any conversion needs to make no modifications or assume it needs an IVA and subsequent Q-plate designation Thoughts on Caterham’s Plans See above Seven Conversions JM shared some animations of EV and Duratec he’s been working on An early EV concept video can be found here:
AMRC - ELLI conversation https://www.facebook.com/photo/?fbid=530986689034888&set=pb.100063706834212.-2207520000. JM talked to the ELLI project manager last week JM to visit and report back ELLI project manager has tentatively agreed to give a talk about the project at one of our monthly meetings - all agreed this would be of interest We had a long discussion about the merits of front vs rear mounted motor, especially in light of the issue converting a mini highlighted above, the DVLA points system and R100 DVLA points system https://www.gov.uk/vehicle-registration/radically-altered-vehicles We discussed how DVLA use a points system to determine if it considers a car to be radically altered R100 https://unece.org/transport/documents/2022/03/standards/regulation-no-100-rev3 At the close of the meeting JM quickly highlighted the United Nations regulation 100 that details how EV powertrains and batteries might be tested. There is some speculation this could apply to conversions and would significantly increase the complexity of a conversion and almost completely rule out the possibility of a home conversion. AOB People thought it would be good to have a place to discuss topics between monthly meetings. JM agreed to set up a WhatsApp group and will email all EV-area members so they can volunteer their mobile numbers if they’d like to take part.(If you're reading this in the future then send your mobile number to ev@caterhamlotus7.club) 27 club members have now signed up for the EV SIG area
Agenda Introductions by new attendees What’s new in the EV world Thoughts on Caterham’s plans for EV Seven Conversions AOB Attendees: John (JM) Mac Dan Tom Jonathan Martin John Intro’s By New Attendees TomBentley, Jag, MG5 and 620R owner Bought 620 last year and now produces 362bhp (PGM) 3rd owner Was originally Chris Hoy’s car Misc and Intros SIG now has 31 people signed up John reported seeing good charging infrastructure in France recently Martin reported trying to regen down a mountain road in France in a PHEV which generated 4 miles of range by the bottom after travelling 6-8 miles. Unfortunately that 4 miles only translated into 1/2 a mile of actual travel back up the mountain. Feb LowFlying EV Article JM showed the 3D model he created for the article’s pictures Model is done in Blender (blender.org) Model based on a CSR chassis, so like an SV but not the same as JM’s final project On close inspection the model clearly won’t work because various components interfere with the chassis It was created to demonstrate the components needed for an EV rather than exactly how it might be executed Under the Radar Guy - now Mr X JM visited Mr X in February and got to look at his 7 EV conversion project He sent JM some pictures of his project that were reviewed on screen on the call He is making good progress now Mr X has included a mechanical disconnect as well as “big red button”. The disconnect is in the form of a lever in the footwell [edited to change from "where the gearstick should be" to "in the footwell"]. Question: can the mechanical disconnect operate at full power - JM will ask and report back (see below) Jonathan asked if his basic configuration is the same as what JM is proposing - yes. Biggest battery pack up front with motor feeding rear diff through prop-shaft. However, a total of 5 battery boxes needed to get his required voltage, current and capacity needs into an S3 chassis. At the moment there is no cooling implemented. Speed and power are limited and so decided to monitor the temperatures once the project is running to determine whether and where cooling may be needed for a future iteration. Conversation about EV motors and failure modes around vibration - causing permanent magnets to fail Zero-EV (now Fellten) City and Guilds EV Course https://shop.fellten.com/event/level-2-and-3-combined-city-guilds-qualification-9/register Course is online tests (up to 12 hours) prior to 2 days of on-site training Online test pulled on a lot of JM’s knowledge of EV’s and electrical engineering. This is not a course for someone wanting to learn about EV’s. It’s really a way of getting a qualification for people who already know what they’re doing. There were 4 people attending the on-site training days. Two working for an EV consultancy startup, 3rd person working on converting a 1970’s VW camper van. People attend the course from all over the world, certainly EU, US and South Africa. Looking to The 3rd attendee was looking at doing a VW camper conversion but having attended the course was starting to get cold feet about what was required. The instructor said that often happens. Factory tour was fascinating. Lots of mini’s, porches, land rovers, etc being worked on. Lots of kit parts on shelving in their industrial units While the City and Guilds course was rather haphazard the online course and 2 days were revelatory and I would consider that anyone considering doing an EV conversion should do something similar. Not cheap at £800 but nor is a conversion John relayed his experiences doing C&G course run by IMI. 6 on course. John agreed that C&G tests were not well set and he had to guess at a few answers. Gave you a healthy respect for what you’re playing with. Also having the certificate is good for insurance and credibility Bonus fact: Fellten is Welsh for “Lightning” I was also given a copy of the latest EV Builders magazine whilst at Zero-EV, see below EV Builders Guide - Magazine https://pocketmags.com/ev-builder-guide-magazine Quarterly magazine about EV conversions Fellten seem to be in the magazine regularly - latest issue has review of their Mini kit with ex-Caterham F1 team engineer Gary Scott driving the car around JM not particularly impressed with the magazine - the title might imply lots of info about converting cars but it seems to be more about showing off finished conversions. However, there’s interesting adverts and tidbits that probably justifies the few pounds yearly digital subscription There are versions available for browsers or iOS & Android apps JM Conversion Update Ex-drift car, known as The Mule. Has never been road registered but has had an IVA Therefore, currently working on getting the ICE based car through its MOT - as that will be easier - and then will apply for a V55/5 registration Once the ICE version is road registered then can take out the ICE and start the conversion The Mule has had a lot of tinkering over the years (removed ignition barrel for instance) and has resulted in much of the electrics not working for different reasons. But now all of it is going again:Headlights - needed relays fitting along with dip/main and flasher dash paddle switches Indicators - needed new flasher unit and relay Fog light - needed dash switch cleaning (internal contacts had corroded) and the bulb mounting bracket was bent and needed adjusting so the rear of the bulb made contact again Reversing light - new gearbox reverse switch (contact lugs broken off of the one installed already, I managed to break another one in the same way trying to get it working, then ordered more from Burton Power as most other places were out of stock). Also needed new lens on the light box - bought from JAL Washer bottle/motor - not installed so eventually got one from Caterham (after it had been out of stock for a few weeks) and fabricated a bracket to install it. Ended up using the motor that was already installed on the car (though no bottle attached to it) because it had different connectors than the new bottles from Caterham Rear number plate light - this was completely missing. I presume it had become the victim of a cone that ran under the car at some point in its life on a circuit. Bought a new LED one form JAL and installed it In order to get at the electrics of the Mule more easily, JM removed the scuttle. This is being fixed back on with captive nuts housed 3D printed “widgets”. The SV chassis has 26 scuttle pop-rivets that will be replaced by these widgets Since the scuttle was off, the battery isolation switch flapped around. So JM 3D printed a bracket so nothing ended up shorting Mr X response to question about mechanical disconnect: “The dogs are undercut so it will take force to open it. At this point the plan is to set up as much mechanical leverage as I can and see….. I did a test with the same box on the fireblade car and opened it directly via the hand lever (no pedal on that car) but I can’t say how it will feel via the pedal. I’m more concerned about negative torque to be honest because with positive torque, hitting the estop will kill the current but there are IGBT faults leading to the failure mode of undemanded negative torque that are not mitigated by disconnecting the battery”
Agenda Introductions by new attendees What’s new in the EV world Thoughts on Caterham’s plans for EV Seven Conversions AOB Attendees John (JM) Dan Tom Jonathan John Intro’s By New Attendees None Caterham Cars and Electric Vehicles JM explained he had spent time with CC recently. Some things could be talked about and some can’t There will be a new car that isn’t a Seven, with all the fundamentals of a Seven. There will also be an EV Seven if there’s a business case for it JM’s thoughts are that CC have realised they are known for the Seven and therefore an EV Seven Also heard that new car (not 7) will be aimed at a new market - so if they’re not going to alienate the current customer base then they may need an electric 7 JM reported he went to the CC new factory opening with the Club AIM announced a new electric car, headed by someone that worked with Bob at Nissan. The AIM car will use an Equipmake drivetrain JM reported that he met Equipmake and CC at Snetterton. Equipmake are based on a business park next to Snetterton and JM had a factory tour. Lots going on at Equipmake and seem to be a very competent operation (need to be careful as they are stock market listed) JM reported on being taken around Snetterton in a 420 Cup - liked the suspension setup and may be useful for an EV. Discussion about putting SwindonPowertrain motor in transmission tunnel of SV. It should fit and would release a lot more space in the engine bay. JM will be visiting SwindonPowerTrain later in May JM Project Car JM reported that his project car now has a V5 and number plate The first decision is to chose the motor May LF will have next instalment of JM’s Putting the EV in Seven series Discussion about how Caterham’s are getting more expensive and how increased expense means increased expectation on quality. Even more so for a new car with an even higher price JM reported that he’s been busy but not on his project JM said he’s now looking at using ID3/4 battery modules now. Has seen them now in a few places and may go for second hand modules that are better density than previous LG modules he’d been looking at. Discussion around how if you can sensibly recover crash damaged car’s EV batteries, then they have probably been over engineered in the first place. Perhaps that’s needed but has the impact that second hand modules are good for conversions Insurance companies far more likely to write off an EV after an accident JM reported that there are new CCS modules now coming to market that also include contactors. JM will try and find out more details. Chinese Electric Cars Discussion around how Chinese cars (including MG) may get a march on the existing car manufacturers Discussion about Charging Infrastructure It’s patchy! M5 and M6 are ok. M1 bad Reports of Liverpool and Leeds also being bad New provider MFG seem to have good (more northerly) infrastructure that works well
Agenda Introductions by new attendees What’s new in the EV world Thoughts on Caterham’s plans for EV Seven Conversions AOB Attendees John (JM) Mac Tom John Adam Rob Paul Intro’s By New Attendees Adam 20 years ago was given a driving experience day that including a seven Took ten years to then buy a sigma which he then wrote off Insurance then paid for a new car and he went for a Duratec Track focused Has a Nissan Leaf where he does VTG Electricity Provider is Ovo Uses car battery and solar to favourably export to grid Rob Bought Seven 10 years ago Recently rejoined club and re-invigorated with car Notes Caterham’s Seven EV Announcement JM has article in June LF about the press day in Swindon JM said the neat thing about the announcement is the battery. Though not going to be cheap to mass produce Discussion about how EV’s should be cheaper than ICE cars to construct and maintain Discussion about heat in an EV and how batteries need to be at optimum temperature. Just a few percent inefficiencies can lead to a few kilowatts of heat being produced and needs to be managed to keep batteries cool in summer (and under high load) and warm in the winter (when car first started). John Kelly, Weber University just did a good video on the “heat pump” in a Tesla where lots of different systems are moving heat around the car:
Reviewed all the press photos sent by Caterham Not all press pictures got released, so we went through them all Batteries are novel because fluid passed between cells inside battery modules 80L/min coolant flow Double cooling that’s theoretically needed Battery pack shape dictated by steering column Youtube video explaining how power (BHP) and torque (lb-ft) cross at 5252rpm
Discussed whether Caterham would use regen. And how the rate of change of torque going from motoring to generating needs to be considered. View that lots of regen on track might not be desirable But driving a car with no regen (i.e. no engine breaking) would also be odd Long discussion about how battery cells are oriented inside the battery module and how there are Aluminium sandwich plates top, middle and bottom of the battery pack that provides cooling channels to feed coolant around the individual battery cells Plan is to run the Seven EV up the hill at Goodwood. But they would need to build two cars in around 2 months, so lots of work to be done before Goodwood Quick discussion about the Nyobolt fast charging concept car: https://www.pistonheads.com/news/electric-vehicles/nyobolt-reimagines-the-elise-as-fast-charging-ev/47316 Caterham’s press shots can be found here (I’ll maintain this link for a few weeks): https://www.dropbox.com/sh/4k33wgvrgkjfr3n/AADkpVJikgxkWG-TvzwZJOKpa?dl=0
