Monday, 24 February 2014

Now it’s done, Do it all again! :-(

So 3 days in from finally getting the charger onboard the EV and I learned to my cost that the Soliton does indeed damage the charger if it is permanently connected to the live traction pack terminals, I got home and went to charge as usual (a little more excited than usual in fact due to the new improved and much simpler charging regime) except this time as I turned off the car and stepped out to unlock the workshop where I charge from I noticed a fan whirring from the boot, Damn! Opened boot to be presented with the charger running whilst seemingly not plugged in! Damn Damn! Check output diode with DVM, its blown! Dead short across 1 of the diodes in the package! Damn Damn Damn!

However luckily I was planning on building another of these cool chargers and had already bought a second identical output diode from Digikey so after another evening of rapid strip down part replacement and reconstruction I was ready to charge once more, however I would be unable to fit the charger into the car again until I had sourced another HV contactor, an email to Steve and a swift meeting a few days later and I had 2 HV contactors in hand (Thanks again Steve)  the second is for the ceramic heater I am intending to fit soon for rapid demisting of the windscreen.


So after a minor rewire of the charge +ve cable via an HV contactor that is activated from the 12v line of the charger (so it switches on and connects the output of the charger to the +ve line of the traction pack) the charger is now back in the car and working as expected. Sweet!

Monday, 27 January 2014

Fitting the EMW Charger into the “ElectroBeat”

So finally this weekend I found the time (Stole the time from my family more like!) to get the charger fitted into my EV.

I began by using a MiniCraft drill (Dremel in the US) with several cutting discs to cut the holes for the two fans, as I began I intended to cut circles and bolt the fans to the car but it soon became apparent that it would be much simpler to cut a single large rectangular hole and leave the fans bolted to the charger case.
After this I moved onto re-orientating the J1772 socket so that the plug would point down and not up (my mechanic had fitted it this way round to avoid the socket cap fouling the ex-petrol filler cap), I discovered that a little minor bending of the ex-petrol filler cap’s closure clip was all that was required to fix this. Checked it all fitted by plugging the J1772 plug into the socket it looks so sweet, massive EV grin :-)

Once this was done I ripped the lid of the charger disconnected the control board and attempted to fit the charger case into the mini boot, it again became apparent that in order to do this I would have to strip the fans off the case and refit them once the charger case was fitted, all in all this was a complete bitch to fit partly due to the addition of a couple of M8 bolts to hole the massive capacitor bracket in place, this needed another hole to be drilled in the cars boot to accommodate the extra bolt length.

Once this was all done I discovered that access to the Bolt holes that I had drilled to hold the charger firmly fixed into the car boot was severely limited by the fact that the bolt hole on the underside of the boot was behind a bulkhead pressed panel, luckily there was a hole in it just large enough for me to get my fingers into and hold the bolt in place whilst I did a little contortion-ism to get the nut on the other end, damn I hate working on cars but heck at least with EV’s there is no bloody oil and s#!t to get covered in, road dirt is about the worst you will encounter (which reminds me I must get my water-pump fixed so I can use my jet-washer again!)

Once the charger was securely bolted into the car I refitted the controller (just 4 nuts as it only needs moving about an inch to the left to allow the charger to be squeezed in place) and drove the car back into the barn as the light was beginning to fade at this point (damn I hate British winters! Oh and if you are wondering why my tone has changed to the decidedly miserable I have just given up smoking again! Whoopeee!)
Once back in the barn lights on (short break for  a cup of tea) and continued onto wiring in the J1772 socket wires to the charger.
When this was done I reworked the charge cables so that they would connect with the new charger permanently (no crappy Anderson connectors here) unfortunately the 50A cable I had was too short so I have had to temporarily extend it with a lower 16A cable for the time being (fused of course, 30A fuse).

I had previously checked to see if it was safe to have the charger permanently connected without the controller damaging the charger when driving and according to Steve (Jozztek) this should be fine (well at least according to his experience of doing this several times before) but he did mention that someone on the diyelectriccar forum had suggested that the charger may be damaged by the Soliton over a long period of time, we shall see as I would rather not fit yet another HV contactor, and I feel that the output diode should be beefy enough to handle it as this charger is seriously over specked for what I actually need in this EV.

So for now I will have to stick to 16A charges (better than 12A which was the max I could do up till now) until I can get a longer 50A welders cable fitted (I do actually have a bit of cable that would extend the existing cable but it needs two crimps to be fitted and I don’t have a crimp tools that is up to the job (borrowed this from Steve when I was wiring up my EV) I will have to get a longer cable from Steve or crimp the bit I have next time I am round his way.

Once this was all done I refitted the fans I had previously stripped and wired them up (a total bitch as I needed to pull the wires through a hole that was fairly inaccessible, but got there in the end.

After this I decided that it was about time I extended all the wires from my driver board to the control board (on the lid of the charger case) so that I can remove the lid without disconnecting all the cables (which has been a pain in the arse since I first put the charger inside its case) this took a fair while as there is around 11 wires to extend each one needed to be Cut/Stripped/Tinned & Hooked, then the extension wires also needed the same at both ends so this was 44 x Cut/Strip/Tin/Hook/Solder/Heat-shrink!

Whilst doing this job I realized that I was talking to myself and was starting to sound like the geek kid out of “Cloudy with a chance of meatballs”, “CUT/STRIP/TIN/HOOK/SOLDER/SHRINK”, man I really need a break from the EV!

Anyway 44 renditions of that mantra later and voila I had a lid that could be removed without breaking the charger.

As I was seriously running out of time (it was pushing 11:00PM at this point) and my partner was threatening to leave me forever (again) unless I left that other bitch alone and came in for some dinner!
I thought it best to stop for another cup of tea and then get back wire up the J1772 ASAP (basically because I have to use this as my commuter car I have no choice but to get the EV charged every weekday night and Sundays ready for the following Monday)

So refreshed (well sort of) I got back to wiring up the 8 meter J1772 cable and plug up to a fuse box I have spare in the workshop, the only disadvantage of this setup is that I have to charge the car outside (in the rain!) The big advantage is faster charging.

So about another 30 minutes or so later the J1772 was wired and ready to go.

Plugged it in and bam (no it did not blow up!) the charger whirred into life, stepped through the motions and began charging the car, MASSIVE EV GRIN! :-))

Finished charging the car at around 1:00AM (16A charge) and it pissed down so I call that a successful full weather test.

And the Beat does look sweet with a proper charge cable hanging out the ex-petrol filler cap.
Might need to earth the car to the mains earth though as I do get a nice tingle off the chassis now :-$ 

Getting used to using the EMW charger

I ran a test a the weekend with the intention of filming the whole charge sequence, it all went well until firstly my camera ran out of space on its SD Card, offloaded the contents and continued filming at which point the DC current clam I had borrowed ran out of battery, closely followed by the AC Current clam I was borrowing from work timing out (odd that it would time out whilst readings are changing but I get is is a cheap one designed for single current readings.
All of this put the kibosh on me getting a complete charge cycle recorded and due to the need to have the car running for Monday (For my work commute) I resorted to just finishing the charge and seeing how I got on with a week’s worth of actual use of this charger to charge my car.
I am charging from approximately a half charged pack to a fully charged pack every week day evening and so far so good I have had to limit the charge current to 12 Amps to avoid melting anything (again!) and this means that it takes approximately 3 hours to complete the charge (Half Charge) I am visiting regularly during the charge cycle to check on things and other than a slightly melted Anderson connector it is all going well.
I intend (if I have time) this weekend to try and get the charger fitted into the car and wire up the J1772 socket so that I can use the heavy duty J1772 cable I have purchased, this will allow a much greater current to be drawn and therefore a faster charge.
However there are a number of constraints more to do with the location in which I am charging the car, currently I have it parked in the entrance of my barn which has a standard domestic 32A 3 pin UK socket supply, as I have already melted several 3 Pin plugs and sockets this is not ideal, the supply for the barn comes from my workshop where the electricity meter is located, this would be the ideal place to connect the J1772 lead and plug for charging but it means that the car would have to be charged outside in the atrocious weather we are currently experiencing ,a good test of the waterproof-ness of my cars electrics you might think.
I have several concerns over this fact and the amount of work required to fit the charge into my car, I still have several things to complete to get the charger fitted:-
1) Drill some fan holes in the car, trivial but time consuming
2) Reworking the fans so that they fit in the car rather than being jerry rigged on the outside of the charger box as they are currently, and wiring them up 
3) Securing the charger box inside the car, already have the holes drilled for this just a matter of bolting it in
4) Securing the heat-sink inside the charger case, I have a problem here as the heat-sink appears to have some voltage on it and the last time I used metal machine screws to secure the heat-sink I got a shook from the case (not good) might 3d print some screws and tap/die them off to fit (not sure if ABS will be strong enough to handle the vibration though)
5) Wiring the output connections in permanently with bigger wires (already have these made up) to avoid the need for Anderson connectors (from my limited experience Anderson connectors are not really up to the job)
6) Wiring in the J1772 socket to the chargers AC inputs, this should be fairly trivial the cable is already in the car, however
7) I need to change the orientation of the J1772 socket so that when the plug is inserted it points down, my mechanic fitted it so the socket points up to avoid the socket cap fouling the ex-petrol filler hinge, I will probably have to mod the socket lid by hack sawing of the tab that is fouling the hinge, as if I intend to run this in foul weather I need the plug pointing down so any water runs down and drips off the cable not down into the plug!
8) Insulating the chargers case from the cars chassis, although this is not required it would be another level of safety if I have a short inside the charger for any reason.
9) I have also been advised that to resolve the voltage on the heat sink issue I might be able to use mica sheet to electrically isolate the bridge/IGBT/Output diode from the heat sink (I need to check this with Valery first though)

Monday, 6 January 2014

Collected Fuel/Charge Gauge.

At last I visited Steve this weekend for just a couple of hours (he is as busy as me) and collected a few bits and bobs, mainly I swapped the V3 Charge Analyst for his V2 as it turns out the guy who makes these has made a big change to the design which means that I would have had to make the Car’s chassis common with the Traction Packs –ve terminal, BAD IDEA! This would mean that if I had the covers off or boot open and was working on the car whist leaning on the chassis I would only need to touch a live terminal an bamm! Instant perm!
The V2 Charge analyst does not have this problem as it does not require a common ground, Steve can’t understand why the guy that makes these has done this as it has essentially blown this product for HV use post V2!
Also picked up the extra cell cables I need for the LVC/HVC circuit and borrowed a DC current clamp to run some tests on the charger.
Steve finally got to take it for a spin and I think he was impressed, although it is not as powerful as his it sure shifts when you boot it, his primary concern was the shit brakes which although I have serviced them still don’t work that much better, I know that 1 Disc on the rear is shot and needs skimming/replacing but even though they are tiny discs and pads so I think I will look at getting bigger callipers and disc’s fitted if I can find some that will fit.

Voltage sensing fixed & Chargers Final Assembly nears completion

Found the problem with my voltage sensing circuit, I have accidentally used a 0.1uf ceramic capacitor for C32 instead of the correct 1uf, swapped it out for the correct 1uf value and tried calibration again, 10 volts better on the first sensing during calibration, and once you punch in the correct value it then senses voltage bang on correct, Sweet!
Wired up some fans I had ripped off a bunch of old CPU coolers I had laying around and bolted them to the outside of the case to suck air through the Ali box I have the charger fitted into now, wired the into the 12V circuit and fitted an AC mains cable for now whilst I continue testing.
I got a belt (Electric Shock) off the case the first time I fitted it into the case and discovered that the heat sink appears to have some voltage on it, proved this by removing the metal machine screws holding the heat sink to the case and the problem disappeared, not sure if this is right but I noticed a post from Arber on the EV forum (diyelectriccar) who has the same non PFC charger and he is also getting around 30v AC on his case, I posted a reply stating I had the same problem and promised him I would check mine to see what the voltage was i.e. AC/DC and how much, but I have not had the chance to test this as yet. However I know it is AC as I know what AC electrocution feels like having put my hands in the wrong place to many times before (use to be an apprentice TV engineer/Tea boy in the days of CRT TV’s) but it would be good to get a reading anyhow.
Continued testing the charger over the next few days and melted a few more AC power plugs :-$, I think it is time to move onto getting my J1772 Lead wired in and working as this would solve all the overheating AC plug issues and allow greater currents to be drawn and therefore faster charging.
I am not really interested in fast charging at home but on the go it would be a very handy feature, I noticed today that my most local EV meet is in Portsmouth around 60 miles from me, my car has 40 mile range so I could stop in to the Little chef at Fontwell and charge whilst getting a spot of lunch get to the meet have a short spin and get back to the little chef for the next charge to bring me home again, it’s that or take the Diesel or maybe I should organise a more local meet.
Damn it is getting exiting I can’t believe I am nearly able to travel in this little electric beauty, talk about Electric Dreams!
Heck maybe I will fit an additional battery box in the front there is plenty of room for it and I could use the extra weight for grip  whilst racing ,but I think I would be better off waiting till I replace my battery completely and by them 3-5 years from now (probably 3) I will hopefully be getting a much better energy density for my cash, this year 170kwh batts are available if expensive and I hear of 200kwh also being available this year, bring it on!

Monday, 30 December 2013

EMW 12Kw Charger is Working!

I just got my charger working for the first time, well an actual charge test anyhow.
Ran the test for around 16minutes, toroid got warm ~35-40Deg so it was definitely charging, it stayed in CC stage for 16 minutes before I unplugged, temp reported on screen was 12Deg, I am using an AC desk fan whilst testing, duty hovered around 25%, this was a 10A test charge. (rose to 26.5% in ~20 mins)
Second test at 16A in & out, all seems to be working even if the sensed voltage values are not correct, charged for around 20 minutes and took my single battery box up from around 76.4v up to 78.5v after disconnecting so it is definitely charging
Superb, now it is time to start my final assembly, I won’t be able to complete it until I have addressed the voltage sensing error issue but heck at least I can now charge my battery with my own charger 
My camera ran out of battery whilst doing these tests and I have stopped to charge and upload, I also tweaked the video settings as a test of a low res 640x480 video to see if I can read the screen’s (charger & DVM) if so I will use these settings as I would be able to record a whole charge cycle (I hope)

There is still quite a bit of finishing up to do on this charger before I can fit it into the car :-
Updates *** Done over Xmas period ***
1) Pot the caps (Update:- Done used electrical silicone)
2) Secure all the plugs, hot glue gun should do it, need to buy one (Update:- Done used electrical silicone as I already had it)
3) Hot Glue the Driver board to the power board, (can think of a better way at the moment) to avoid road vibration loosening boards. (Update:- Done used electrical silicone)
4) Drill some holes in my car for ventilation of charger, due to space issues I will probably fit the fans on the outside of the charger box.
5) Change output connections for an Anderson style connector (Update:- Done)
6) Rewire my charge connections in the car to accommodate a single charger connection, I currently use 2 separate chargers to charge with, kindly borrowed from Steve of Jozztek (Thanks Steve you are a life saver) (Update:- Done)
7) Wire up the J1772 Connector in the fuel filler cap to the charger (the charger will have to be in the car for this to be done)

Monday, 11 November 2013

Charger repair begins

Sunday I was still feeling unwell but decided to try and pickup from where I left off about a month ago with my charger build, Solved the display refresh issue by downloading the latest firmware release (V11) after reading the last few entries on the diyelectricar charger thread last night, luckily this latest post included the TimerOne & LCD libraries, after downloading installing libraries compiling and flashing the display issue has vanished!

Horrah, I just hope when I get to the HV tests I don’t blow another IGBT/Driver/Isolator as this charger is starting to look expensive already.

However my envy of seeing other people using these chargers successfully should keep me going ;-)
Can’t wait to charge on the go, I am currently running my EV (for around a month now) to and from work via School for my daughter I do around 25 miles round trip and use approximately half of my 10kw traction pack, I only specified 40 mile range so currently it is all looking pretty good.


I am borrowing a couple of Zivan chargers from a friend who’s EV is off the road at the moment, charging takes me around 2 to 2 and a half hours total although I have to revisit half way through to switch off one charger as I am using one charger to charge two (paired) of my three battery boxes, the other to charge the third.

I hope to get my HV cut off boards (installed in the batt boxes) to control the charger so I can simply plug and go rather than timing everything.

Test1                                                       Test2
video
Calibration Sequence