Heat or no heat

So I thought I'd assemble and install my brilliant PTC heating system. It consist of three 500W elements meant for 110VAC, a fuse and one of the temperature monitoring relays that came with the elements. Seemed to work really nicely like this, with no air flow going throught them. Almost scary even, because the elements quickly shot up to 100 degrees Celsius and kept on going until 200 degrees.

Imagine my disasppointment when I had them installed and found out they made nearly zero heat once in action. Oh, if I put the blower on first setting there was a little bit of heat, but not nearly enough to clear the windshield. I suppose I just have to give up and find a liquid tank heater to get the job done. Meh.

It wasn't a complete waste of time though, because now I have the wiring ready for whatever heating system I end up with. The smallish 80 amp contactor in the right is what controls it. The DC/DC converter wires come in from the left. The Kelly controller is sticking in from the top and motor wires go out to the left. That throttle pot system is a bit flimsy still and it will need another spring, but that's another improvement that might have to wait until later.

Loose ends

I was tying some loose ends today. Not that I'd run out anytime soon. One of them was tying down the battery box. I decided to do it this way for now and maybe change it later. Hopefully the inspector won't have a problem with this approach. Then again, it's not a huge issue, if I have to go for a more permanent fix. The thick black wire in the picture grounds the battery box into the chassis. It's not very pretty, but gets the job done. Another little thing to tidy up later, if there's time and interest.

As is usually the case with French cars, my Xsara also had it's spare tire under the boot, outside the car. I believe it's not required to have a spare wheel anymore, a lot of new cars don't, so I figured I'd take it out. It was a full sized wheel with sturdy mounting system, but I was still suprised to find out the pile of crap came in at a hefty 20 kg! Very nice weight savings indeed. Almost half the weight of my batteries.

I also picked up the Power Steering pump which had the piece from the old pump fitted into it's now stubby pipe, making it compatible with the plumbing in the car. This is to me the most favored solution since now I can keep buying Xsara plumbing and 307 pumps as long as I like, if they break.

A problem surfaced regarding the VAG vacuum pump. I don't know if it's by design or if the pump is broken, I'm guessing the latter, but once I got everything put together and running otherwise fine, the vacuum would escape through the hole in the pump which it uses to blow out extra air from the vacuum side. Bloody annoying. I took the cap of the pump and found a couple of seals, which seemed fine, and nothing else broken either. Maybe I can find a one-way valve that would keep the vacuum from escaping? That would fix the issue. The vacuum relay I got from ebay works as advertised.

The non-update

Not much to be told at this time I'm afraid. The lack of a warm, clean garage is slowing me down. I did get the Power Steering pump working though thanks to this blog post I found. It was just as simple as they told. Just connect the two big wires to the 12 volt supply and two of the control pins to plus and it ran. Ran quiet too. I think it will make for some excellent power steering. Possibly even better than what the car originally had. Now I'll just have to get the piping fitted.

Still trying to find an electrician who would check my high voltage connections. Well, it's not even high voltage really. It's really, really low voltage at around 80 volts DC, but the rules say they must be inspected. Apparently it's enought though that the eletrician checks just the high voltage circuit and general installation of high voltage components and the rest of the E100 paper can be dealt with at the inspection. That means I'm pretty much ready for the inspection. Well, maybe I need to install those charging plugs and bolt the battery box to the car, but other than that it should be all good.

The rest of the components for the brakes and heat did also arrive. I should now be able to construct the vacuum assembly for the brakes. Not expecting any problems there. Just a matter of some tubing, a relay and a piece of aluminium to keep them in place. I'm kind of hoping to get that done within the next week. Either that or the heat, which will consist of three 500 watt PTC elements. I will replace the pollen filter in the car with those elements and see if the result is sufficient heat to pass the inspection. Fingers crossed.

I'm also constantly thinking about replacing my expertly welded motor to transmission adapter with an industrial flexible joint. It may have to wait until later though. The thought of once again removing the motor is not extremely appealing at this point. I will need to improve the motor mounts though. Oh, such a long list of little things to do here and there.

Parts galore

So I've got plenty of parts now. A vacuum pump from VAG (Audi), a blue funny-shaped pressure bottle also from an Audi, power steering pump from a Peugeot 307 (just like my daily driver!), a couple of 80A relays for the charging connector and some trailer connectors I was thinking I'd use for plugging in the charger. That way I could put the same connector on my motorcycle as well and switch chargers between the two at will.

For the power brake setup I'm still waiting for a vacuum switch to arrive which would allow me to control the pump via relay to switch on and off based on amount of vacuum in the bottle. The pump itself works great and doesn't make too much noise. It had a three pin connector, but once the plastic around it got removed along with a little relay board, there were just two normal connectors on the pump, which simply take 12 volts to run the pump.

The power steering is a bit less clear cut at this point. The pump has a metal tube coming out of it for the high pressure output. That needs to be somehow made to fit the original plumbing in the car. Luckily I have some contacts to a local hydraulics company so I'm guessing they might of help there. The pump also has a number of wires in addition to what are clearly the main 12 volt power lines. I tried to plug the 12 volt wires directly into a 12V battery, but nothing happened, so there must be a board with some logic somewhere in there. I'll have to try to find a pinout for the connector with all those little wires or take the damn thing apart to see if I can find a way to "hot-wire" the pump into action.

Other than that the only thing that I don't have parts or a plan set in stone yet for is the heating. The current thinking is to replace the pollen filter with some PTC heating elements. The simplest, yet the most expensive solution, would be to get a ready made hot water system and plug it into the existing plumbing. But we don't usually go for the expensive-but-easy solution, now do we.

Little progress here and there

There's been a little bit of progress here and there. I've connected the DC/DC converter to the 12 volt system and succesfully too. The little voltmeter that plugs into the cigarette lighter outlet now shows 13.5 volts when I have power on. The converter was drawing about an amp when just charging the auxiliary lead acid battery, but with all lights on the current draw jumped to about 5 A.

I've also mounted the Cycle Analyst display in the dashboard. It's blocking the view to the tachometer and fual gauge, but they're not working anyway. Also it blocks the bright out-of-gas light as well, which was rather intentional. It does not block the speedometer or any other useful signals though.

In addition to the Cycle Analyst you can see a red flip switch in front of the gear stick. It has two positions. Forward or "AJO" activates the main contactor (provided that the car is turned on using the original key) and lights the switch red, albeit dimly. Flip towards the rear of the car or "SEIS", the main contactor deactivates and the car will not move by it's own power. Should be pretty easy to do that even in an emergency. Also you can always switch to neutral by hand, which should be doable even without the clutch.

I was also looking into some heat. I dismantled a 1000 W 230 VAC cabin heater that I got for 9,99€, but unfortunately the PTC heating element inside didn't put out any useful amount of heat at 80 VDC. Also it was quite small and pushing all the air though that small element would have been less than ideal. I did figure out a place to put it in though. There's a pollen filter that's easily accessible that I think I might be able to adapt to hold whatever workable heating element I can get my hands on.

Regarding UNECE R100 (aka. "E100-sääntö")

I have been talking to the local vehicle inspector about the UNECE R100 rule, also known in Finland as the "E100-sääntö". I thought it would help fellow converters in Finland to share what I've discovered.

As you may or may not be aware, the R100 is required from all conversions done in Finland. The local inspector whoever doesn't know anything about electrics, so what you need to have is someone with the proper qualifications to check the vehicle.

The next question is which version of R100 do you need to follow. The answer depends. Any vehicle must adhere to a version. Even if it's 1961 VW Beetle, you have to pick one to follow. There wasn't a R100 paper then, but nevertheless you need to follow one.

For a 1997 vehicle like mine you could go with the version that was in effect at the time of the first registration of the vehicle. That would to my knowledge be the 1995 version. However I can't find a version of it in finnish and the 2002 version, strangely published in 2009, seems to have pretty much the same text. So I'll probably go with that. You can always use a newer version.

What you don't want to do is pick the fresh August 2013 version. It seems to have some horrible requirements for the battery box construction, testing and so forth. Just goes to show that the OEMs are really trying to do everything in their power to stop people from building their own EVs.

All of this of course only applies to M and N class vehicles, or cars and vans. Motorcycles have no such requirements as far as I know. Unless of course they're new enough to require EMC testing.

As for the paper itself I still maintain that you should probably only be concerned of section 5, since it's the only section which really lists the requirements proper. The rest of it is definitions and type testing approval crap, so I believe you can ignore that. YMMV though...

ps. I've prepared a document with checkboxes to give to the electrician. It's in finnish. If you'd like a copy, throw me an email. The address is at the top the blog. It is still untested however.

Good old back and forth

I had a little bit of the good old back and forth fun with the car last week. That's to say I got the 12 volt systems wired up as well so I could jump in the car, turn the key, flip a switch and press the acceleration pedal. Not just that, but even make the car move by doing so. And move it did. Shamefully I have zero photographic or video evidence of this event, unless you count this picture which shows that the vehicle has indeed turned around.

I tried third and fourth gears which both seemed fine for taking off. No clutch required, or available, for that matter. Reverse gear was a little bit more problematic. Too much power available resulting in jerky movement unless pressing the pedal extremely gently and letting go at least as gently. Probably this jerkiness was what bent my support structure too. Oh well. At least my welds were stronger than the thick angle iron! That's worth something, I suppose. Also goes to show much power a small 8" electric motor has.

It's also quite amazing how simple my 12 volt electrics are. Especially compared to the complicated original wiring of the petrol engine. I have most of the original wire bundle ziptied in place just to get the three wires that are required for the speedometer to work. Perhaps I will remove more of the extra wiring later. All the new electric car wiring is on top of the case which houses all the high voltage wiring and the 0-5k throttle. Just a few fuses and a single relay so far.

I've also been talking to the authorities and my plans for power brakes and steering seem solid. I'll need to implement more heat that I'll ever need, but I think I'll figure that out as well. For the UNECE R100 regulation the final word is that I'll need to have my wirings checked by a certified professional and get a paper for it. That should be enough for the "MOT" check. Sounds reasonable to me.

Aux battery still needs to be secured in place.

Needs a bit of tidying up.

The mess of original wiring. Actually in use: 3 leads.

WattiViestin lukijoille

This post is in finnish, mainly for the readers of my writing in the local WattiViesti magazine.

Muutama lukija on ottanut yhteyttä WattiViesti-juttuni johdosta. On kyselty mm. mistä käytettyjä komponentteja mahtaisi saada. Omat moottorini löysin Sähköautot - Nyt! -sivuston foorumin ilmoituspalstan kautta. Valitettavasti käytettyjä komponentteja on Suomessa liikkeellä mielestäni varsin harvoin. Toisaalta kerran hankitut omat komponentit on mahdollista kierrättää ajoneuvosta toiseen. Eri asia sitten on, kauanko Trafi suvaitsee hyväksyä mitään muutoksia. Suunta ei ole ainakaan parempaan päin. Syytä toki pitää etsiä myös kauempaa sekä paikallisesta lainsäädännöstä että EU-tasolta.

Toinen kyselty asia on sähkömoottoreiden teho. Jotain osviittaa käytettyjen moottoreiden tehoista saa esimerkiksi katsomalla Kostovin moottoreiden vertailua. Sähkömoottori kuitenkin eroaa polttomoottoreista samaan tapaan kuin esim. Diesel-moottori eroaa bensamoottorista, mutta vielä radikaalimmin. Tehohuippua ei esimerkiksi ole vaan moottorin täysi vääntö on käytettävissä heti kierrokselta nolla. Muunnetulla sähköautolla voi täten lähteä liikkeelle paikaltaan ilman kytkintä esimerkiksi jopa 3- tai 4-vaihteella. Oma kWsara-projektini ainakin näyttää kotipihassa liikkuvan näillä vaihteilla ihan hyvin. Peruutusvaihteen välitys on turhankin tiheä ja auto tahtoo singahtaa taaksepäin.

Moottorin lisäksi tehoon vaikuttaa toki myös käytetty ohjain ja akusto. Omaan autooni tuleva ohjain toimii 120 volttiin ja 600 ampeeriin asti, joten sen laskennallinen huipputeho on 72 kW. Todellinen mitattu teho voi sitten olla jotain ihan muuta ja tuo vääntökäyrän erilaisuus kannattaa edelleen pitää mielessä. Sähkömoottorin vääntö kun on tasainen aina sen huippukierroksille asti, jonka jälkeen vääntö alkaa loivasti laskea. Näiden asioiden lisäksi akuston tulee myös pystyä antamaan riittävä määrä ampeereja ja voltteja "kyykähtämättä". Teho on siis sähköautossakin monen tekijän summa.

Voin listata käyttämieni komponenttien hankintapaikkoja sitten kun olen varmistanut, että niillä todella pääsee muutoskatsastuksesta läpi eikä Trafi ala vaatia jotain sellaista, jota heidän ei mielestäni pitäisi.

Get your motor running, again

Yesterday I spent the whole day working on the car. It was worth it though. I got the high voltage parts all wired up and the wheels spinning using the controller. Here's the proof.

I had the idea of putting the high voltage cabling inside some clear plastic tubing, but the cables didn't want to go in so I just gave up on that idea. The cables routed below the car doesn't look half to me though.

Plenty of room below the car now. Kind of makes me sad to have all that space that cannot be easily put to use. Oh well. At least I got a lot of crap out that could fail the yearly check.

New cable

I finally found a good place to get some proper, orange 50 mm2 cable and other useful stuff for my electric car conversion. To my surprise the place to go to is IKH. They sell all kinds of tools and tractor parts, but also heavy cable and such. They had up to 70 mm2 right there in the shelf. I figured I could get away with 50 mm2. Especially since I'm not exactly creating a supercar.

I got 10 meters of the cable. I had some red cable from Biltema before that was 6 m in length, but it turns out it wasn't quite long enough. I hope 10 will do. Maybe I should have measured how much I need. I also got some clear 40 mm diameter tube to use as a conduit from the back of the car to the front. I got the idea from this Damien Maguire's youtube video:

Very nice, clean and hopefully durable solution. My cabling from first go from the trunk to below the read seats, where there are a couple of holes already available for bringing the cable down to the underside of the car and then using the exhaust pipe tunnel into the front.

The heater in the picture is a cheap 1000 W cabin heater. I'll see if the heating element would happen to work on 80 volts DC as well. The fan most likely will not work in any case.

Tank out, batteries in

Yesterday I finally took out the gas tank from the kWsara. Main motivation was to make room for battery cabling. I've decided to have a single simple battery box in the trunk for now. It's actually an aluminum box from Biltema. Right now it houses the 25 CALB SE40AHA 40 Ah cells from the kWsaki motorcycle. They should be good for about 30 kW and 3 kWh.

The battery box also houses the main contactor and a cut-off switch. Essentially all electric power can be contained within the box simply by turning the switch off. I also got some gland nuts for the cables to exit the box in a clean and secure way. Cables within the box are just 35mm2 for now, but the longer cables are 50mm2. I'll need to get some more though. The 6m roll of cable I got earlier doesn't reach to the front of the car and back.

Taking the tank out took some doing. First few bolts came off nicely, but just as I though I had them all out I found the last one. For some reason the last one always turns out to be the one rusted out and nigh impossible to remove. Eventually it did give up and I was able to wiggle the tank out from between the handbrake cables. Spilling of some gasoline left in the tank could not be completely avoided.

I also used a 5 V 2.5 A D-Link power brick to top up the the cells which we're a little lower than the rest. Now they seem to be quite happily resting at about 2.95 to 3.02 volts like the rest.

Taking apart

Yesterday I proceeded to take apart the battery pack of the kWsaki motorcycle. I'll need the cells for my initial build of the kWsara electric car. I'll see if I can get more batteries later for the car and/or the motorcycle. Of course if I can't get the car to pass MOT then I won't have to.

In any case I thought it would be a good idea to empty the pack before dismantling it. This way it would have the least power stored in case I mess something up in the process. It turned out to be a little challenging and I couldn't avoid letting some sparks fly, so I guess I was on the right track. The minus cable of the pack had slipped into contact with the positive end of the 12 V lead acid battery. A little slip of a wrench into the chassis of the matorcycle resulted in some fireworks along with the bolt in the end of the minus cable welding into the battery terminal.

So yeah, let's be careful out there. Other than that there were no mishaps. I had pushed the pack down to 50 volts, about 2 volts per cell, but it had bounced back to 74 volts by the time of disassembly. All but two cells were at 2.95-3.00 volts. The remaining two were at 2.71 and 2.80 volts. Not sure why, but I may have sucked them a little bit more empty while bottom balancing, they may have been worse cells, I may have hurt them by sucking them too low or maybe some of the sparks I've made have caused them to get a little bit more empty. The difference isn't very big though, since the voltage drops very quickly below three volts. All in all I'm not worried and will just add some more juice into those two cells or suck the others a bit lower.

The cells aren't very clean due to my open design of the battery box and the fact that the braces had rusted rubbing some of that rust into the cells. The cells whoever seemed quite uninterested in their external appearance. Perhaps a more close box would be in order though. The next incarnation of the battery pack will be different anyway, so I'll see what I can do. That's for next summer in any case. I took the bike off insurance for this season.

kWsara original electrics

Not to be completely devoid of actual electric vehicle building I can report that I've been playing with the original electrical system of the Xsara, now known as kWsara. I haven't been able to get the original speedometer or tachometer working, but instead of I've figured out how to make all of the defunct instrumentation both inactive and silent. Silent especially concerning the immobilizer, which in addition to having a light lit also made a nasty sound for about half a minute when the key was turned. All this actually happened by just unplugging the fuse number 25. I also lost outside thermometer and clock, but those are hardly relevant.

What's interesting is that the owner's manual that came with the car seems to be completely wrong on a number of fuses. For example, I lost the cabin blower by unplugging number 21, even though it didn't have that listed. Also the very useful number 25 didn't list the immobilizer or instrumentation at all. Luckily the car came also with a Haynes manual, which I just happened to notice had the fuses listed as well. Turns out it's list was much more accurate or perhaps the owner's manual was missing some information intentionally so as to prevent fiddling about with stuff regular owner's are hardly encouraged to fiddle with.

Also an interesting discovery was made when I took out the glove box. I had been wondering why there were wires coming out of the fuse 5, which is for the ABS system, but hadn't given it much more thought. It all became clear when I noticed a hidden switch in the back of the glove box. Turns out some clever individual at some point in the car's life had decided he really didn't like ABS. I'm rather hard pressed as to why anyone wouldn't want such a useful system, but hey, people do a lot of things I don't understand at all.

Needless to say this possibility of unlegal ABS disablement came to an end and the mess of wires was one again replaced by the 10 A fuse that should be in slot 5. Additionally I've been able to solve the issue of front fog lights turning on automatically, which they obviously should not be doing. This was solved by disabling the automatic lights on feature which is common in cars around these parts, also by removing the fuse to that system. The real culprit is the left lever which controls the turn signals and lights in general. It seems to cause different problems in different french cars. In my 307 the worn left lever causes a similar, but slightly different problem of lights going from automatic on to full on at times, which causes the instrumentation light to flash on and off.

What I haven't solved yet is the issue of heat. In order to modify the heater core in this particular vehicle it would seem necessary to remove the whole dashboard. Not something I'd be terribly thrilled to do. The other option is to try to device liquid heating under the hood to produce the heated liquid which the petrol engine previously took care of. So it's down to dismantling the dash, liquid heating or some third option which I haven't thought of yet.

Call for Top balancers

I'd like to hear from any readers who are using or advocating "Top balancing". Specifically, I'd like to hear how you do it and what science do you think it's based on.

To me it more and more looks like "Top balancing" is something that you can't even do they way you think it can be done. Massaging as much energy in the cells by "boiling" them at a certain voltage doesn't even seem to result in evenly charged cells.

There's a couple of ways you could try to convince me otherwise. First you could "Top balance" your pack as well you can, discharge and recharge. If you have indeed managed to "Top balance" your cells they should all become full at exactly the same time, each and every time. In other words, if "Top balancing" works you'd need to do it only once, just like you only need to Bottom balancing once. From what I've gathered this is not so. And if it isn't, then it doesn't really work. You may think they're all full and balanced at the Top, but what you're really measuring is charge voltage. Nothing else.

Another test I'd like you to do is to "Top balance" your pack as well as you can and then disconnect the whole pack from everything, including BMS and any load. Completely isolated. Let it rest a day or two. Record voltages from each cell. Are they the same? If not, they cannot be at the same State of Charge. Open circuit voltage seems to be indicative or charge state, but only when left disconnected for a long time. This is because the Lithium ions need to settle before the reading is realiable and also the reason why "Top balancing" based on charge voltage doesn't seem to be based on anything.

If you are a proponent of Cell drift, which I haven't seen at all, I'd like to keep those cells disconnected and record the voltage of each cell once a day for as long as you can bother. If cell drift does exist and is measurable, you should see your cell voltages start to go down and differ from each other. Ideally this should be done on a new pack which hasn't been massaged to death by excessive periods of "Top balancing". This is because I'm pretty sure you can see the cells doing all kinds of weird things if you've been torturing them by cooking them at say four volts for days.

Disclaimer: All of my battery ramblings are based on my own experience and Jack Rickard's findings. They are applicable to CALB SE- and CA-series cells. Other cells and chemistries may at least require different voltages.

All kinds of progress

I've been making all kinds of progress. The motor is mounted to the car and I also decided on a controller. In fact, I went ahead and ordered the whole lot, including the controller, a DC/DC converter and an assembly for the controller.

But first things first. I pieced together something to firmly attach the four points that needed attaching. The motor itself, the transmission, the drive shaft and one of the original motor mounts. The only way to get it done was to just try to position everything the way they seemed want to be and start welding together pieces of steel to keep them there permanently.

I think it came out quite fine. You can judge for yourself be looking at the pictures below. The little triangular piece attaches the drive shaft and the motor from below.

I was browsing the Kelly Controls website when I came across their KHD12600D controller, which they had on sale. I added the assembly for it and a DC/DC converter too. They had reasonable prices and also reasonable shipping fees, which is not usually the case. They came through amazingly as well. I put in the order on Sunday, got an email from Kelly on Monday and DHL delivered the package today, Wednesday. Ten out of ten for both Kelly and DHL.

As you can see the controller came fully assembled with contactor, pre-charge resistor, diode and fuse. Very nice. The only ugly part was the crap on the other end of the DC/DC converter. Not very professional. Tried to clean it up a bit myself to make it a little more bearable. That was after I had taken the photo.

Next up mounting the assembly into the car and loaning the battery pack from the kWsaki electric motorcycle. Obviously a box to put the batteries in must also be deviced. After that it should be time for a little test drive. If that goes well I'll need to tackle the nasty but important power brakes and cabin heating.

Mr. Bigweld

Last time I welded it was in school. It didn't go too well so I've been not doing it since. Couple of months ago I finally bought a welding machine to make new battery boxes for the kWsaki electric motorcycle. Haven't got around to that yet, but I did put the machine into use now.

I had adapters that fit the motors on one end and presumably a Subaru flywheel at the other (motors were prototypes for the Elcat). Having decided to drop the clutch for now I went on to take one adapter and mate it to the insides of the clutch disc assembly that fits the transmission.

Turns out I could put a bolt into the shaft and the nuts that fit the bolt will just fit inside the piece from the clutch disc assembly, so if I tighten everything up they should align pretty well. In the picture you can see my first attempt, which didn't come out straight and I had to take apart. In the second attempt, which then was the second time I'd weld in 20 years, I put just four small welds and let it cool. Then I filled the spaces between them. It seems straight now.

I have no idea whether it will last, but at least if the breaks there shouldn't be any damage.

In other news I found out that the laptop PSU which I use as a DC/DC converter in the kWsaki had drained the 12 V battery down to 3,5 volts. I had nothing else connected. Looks like I'll have to add a switch to disconnect everything from the 12 V battery too when the bike is not in use.

I did get the battery back though. The 12 V charger wouldn't start charging the battery since the voltage was so low, but then I first connected the other motorcycle's battery in parallel, started the charger and disconnected the other battery. Next morning the battery was happily at 12.8 volts.

Spin of the Wheel

So I had a test fitting of the motor. Everything else went pretty nice, except my attempt in finishing the adapter plate contruction in place turned out to be a little challenging. In the end I also decided that I'll drop the flywheel and the clutch altogether and go for a direct coupling. It'll save weight and I noticed that the electronically driven tachometer didn't want to work anyway without the ICE in place. So after I had got the wheels spinning I took everything apart again.

As you can see it really is better to be lucky than to be good. One of the bolt holes in the drive shaft support just fits a hole in the motor. I'm not sure it's quite enough to hold the support in place and if it will still match after I've taken the flywheel and clutch out, which may alter the motor position.

Charge points

Just a quick update; I started a shared Google map of public charge points in Finland called Latauspisteitä. Let me know if you want to contribute and I'll invite you in. Otherwise, just enjoy. So far I've only got three points mapped in the Satakunta region.

Update: Found Fortum's charge point map for Nordic countries: http://map.chargedrive.fi/mobile/

Porin Ässät!

In case you were wondering, I can't resist posting about the Finnish hockey championship winner, a team which my late grandfather made possible by negotiating the union of two local teams in 1967 and also came up with the name for the team, Porin Ässät. It's spade logo and team colors were then chosen to go with the name. It's a shame he passed away just a couple of years ago, especially since the last championship for the team was from 1978, just a few months before I was born.

The championship is ours and I was there! Go Ässät!

First ride of the season, car progress and more

Here's the bike after the first ride of the season. Only a little less than 20 km leisure cruise. Everything still works as before and top speed of the ride was 104 km/h. A total of 20.62 Ah or 1481.4 Wh was consumed. Max battery amps were 422.5 A and minimum voltage under load 57.2 V. The bottom fairing is missing because it needs cleaning and perhaps I will also modify it a little for hopefully improved aerodynamics. I also bought an extended front fender from ebay to reduce water and crap flying into the motor and batteries

My KP-K 2000 W charger doing it's thing. I just keep it in a large tank bag from Biltema. It just fits with enough clearance for air flow. All 20 amps going into the 40 Ah pack with no problem whatsoever. I'd charge faster if I had a bigger charger and was comfortable with pulling over 2000 W the usual Schuko plug. I had outlets with a 16 A fuse installed, but just the other day I noticed the charger's connector getting pretty hot. For faster charging better connectors would definitely be in order.

I also started putting together the motor with the flywheel, clutch and so on. It's a bit more ghetto than I'd like, but I'll have to make do with the time and the tools that I have. At least I'll have room for improvement later if I find myself bored and with too much time in my hands... Right, maybe in thirty years or so when I reach retirement.

A bit of news I actually picked up in the local newspaper, Fortum and Nissan along with the ABC! stations have teamed up to provide a network of 50 quick charge stations in Finland. With Nissan on board there should be no question of whether they'll be CHAdeMO or not. The good part is that it's the best option available right now. The bad is that it's highly proprietary and not available for free. However, I did find an open-chademo project which hopefully will make it possible for private converters to equip their vehicle with a CHAdeMO plug. Me included, I hope.

Update! Looks like the charging stations may actually have both CHAdeMO for 50 kW DC and Mennekes for 43 kW AC charging. At least according to this press release from last year. Nice!

Why you shouldn't fully charge your cells

In my previous entry I wrote about the Swedish paper on Lithium battery cycle life. I kept thinking about the results and came to an interesting conclusion on why you really shouldn't fully charge your cells.

Consider a scenario like the one in the paper where you would Top Balance your cells and fully recharge them to 100% state of charge every time and then discharge them to empty. You'd be at 80% capacity in about 2000 cycles as expected.

But if you didn't fully charge your cells, but instead chose to undercharge your cells like we do in addition to Bottom Balancing? You might not see the 9000 cycles that they got when they only charged to 50% SOC, but I'd bet you'd get to 6000 easy. Even that would be triple compared to Top Balancing.

In order to get maximum range a lot of people will Top Balance, use a BMS or try to find other ways to maximize their traction pack capacity, for example by trying to even the cell charges on the fly. What they don't realise is that if you try to push as much into the cells as you can you are killing them much faster than you could be.

By 1000 cycles of 100% charging you'll have less capacity in the cells that you would have had if you just undercharged them in the first place. And the loss is permanent. There's no way to get them back. Undercharge and those cells will have that 90% charge much longer than the fully charged, Top Balanced pack takes to reach 80% capacity.

Top Balancing might give you the maximum range right now, but after a couple of thousand cycles they guy who only charged to 90% will probably have longer range and healthier cells.

If you have more money than you can ever use, or happen to sell batteries, then Top Balancing is for you. Otherwise, in the long run, undercharging is the smart thing to do. Don't forget to Bottom Balance.

Update! Here's a link to the paper: http://komar.bitcheese.net/files/JensGroot.pdf

Disclaimer: All of my battery ramblings are based on my own experience and Jack Rickard's findings. They are applicable to CALB SE- and CA-series cells. Other cells and chemistries may at least require different voltages.

On swelling and battery life

Ok, I'll just steal that one from Jack's University of Batteries, but I do think it holds true. Swelling is telling and if your cells swell you are damaging them. Hence there is no need to bind them together tight, unless you want to destroy them by overcharging or, oh, let's say by Top Balancing, which really is just a form of doing that.

Another very, very interesting thing is the excellent paper from Sweden Jack is also kind enough to present to us. What's apparent is that to get the 2000-3000 cycle cell life (down to 80% capacity) you need to continously charge to 100% and discharge to about 10%. I think you'll get the same results by Top Balancing as well if you boil your cells at 100% SOC for extended periods of time. And every time you charge to 100% you're harming the cell, so it's really better to Bottom Balance and undercharge a little, say by charging to 3.5 volts per cell. It's the best way to take of your cells really. You only charge them to a voltage and stop immediately.

The test went on to 9000 cycles with LiPO cells in cyclic simulated EV use before the 80% capacity limit, if you didn't charge them over 50%. It didn't matter how fast you discharged. They lasted better if you went from 23 degrees Celsius to 35 degrees. I know it's LiPO cells, but they should be similar enough for all this to apply to LiFePO4 cells as well. Nothing whatsoever in there that would support anything the BMS people are claiming.

I'd go as far as claiming that if you only have 80% capacity left after only 2000 cycles you've probably been doing something wrong. If you are using a BMS then it's your BMS that is harming your cells.

Another thing to take home here is that discharge rate doesn't matter, which means I'm definitely going to remove any artificial current limits in my motorcycle right away. The SE40AHA cells can put out 400 A, that's 10 C, and I'm going to take it all. My AXE7245 controller could go up to 450 A. I will add some cooling though, I have a 8" fan and a 3" marine blower that I'll be experimenting with, but more on that later.

New battery and first charge

New aux battery, 15 V PSU, main shunt and a fuse.

I installed a new auxiliary battery yesterday. It's a 12 V 12 Ah lead acid battery from Biltema, product number 80-268. I'm charging it with an old Toshiba laptop power supply, which puts out a maximum of 5 A at 15 V. It's a little high, but we'll see how this goes. Previously I used old, small UPS batteries, but they probably weren't very good for this purpose and pretty much died. Without the lights on the brick seemed to put out less than an amp, but when I turned on the headlights it ramped up to 5 A. Obviously it's mean for 100-250 VAC, but it seems to run from 80 VDC as well. If the main traction pack falls much below that it will give up, but I suppose that could actually be a good thing. At least it won't drain the pack empty.

That's my fully charged voltage for 25 CALB cells.

I also recharged the traction pack for the first time after the winter. It had been sitting about six months. I had used it to test the TTL200C motor a bit since the last charge and also gave the ME1003 motor in the motorcycle a little spin just before the charge. Only 1.39 Ah went in. So I can pretty safely say the cells haven't discharged by themselves at all. If I hadn't used the pack at all this would equal about 0.5% self discharge per month. Alas I have and no such thing exists. The specs on these cells aren't lying though. 0% is still below 3%. It's really just a number they came up with when they got tired of silly people asking what's the self discharge and they wouldn't believe there is none.

One last shot of the new Cycle Analyst placement from a slightly better angle. Very, very nice.

Looper conversions

Just watched Looper on Blu-ray. Not a bad flick at all. Something that caught my eye were the vehicles. The makers of the film have stated they wanted a sort of a Cuba-ish feel to the vehicles in that there are old beat up vehicles that have obviously been converted to run on something other that originally ran with. Just like they have replaced engines in the old US cars with Soviet diesels (or so I've heard) in Looper they seem to have converted vehicles to run on a variety of fuels.

The main character drives a mint red sports car which seems not to have been modified in any way so it probably still runs on gasoline. Many cars have some added tubing going around the car from exhaust pipe are to gas cap. One of the characters drives an old Japanese motorcycle with some sort of turbine thing replacing the whole lower part of the vehicle. Many cars are also seen with solar panels on all flat surfaces.

That may not be very far from what the future might look like. Gas guzzlers will never go away, but as the price of gasoline will inevitably rise as the supplies eventually dimish a lot less people will want to drive them. It'll be a luxury reserved for the rich and those who restore or keep servicing old classics. Many will just drive on eletricity and some may opt for a fuel cell vehicles. Some will stick to ethanol.

It's just sad that the legislators (fuelled by lobbyists) try to prevent this future of modified vehicles. Let's just hope that tide will turn without the need for a anarchist future like the one depicted in Looper as well.

Spring is coming

It looks like spring is coming. For a nothern motorcyclist the sure signs are increasing amount of dry, ice free asphalt and the accompanying urge to tinker with two wheelers to get them ready for the season. Today I finally did something I had been thinking about since I got the bike inspected last summer. The Cycle Analyst was placed in a less than optimal location below the lock and rather badly in the way, not to mention hard to read while driving. Now it has moved to a better position above the original instrument panel. Looks very good and should be much more user friendly. Good times.

ps. I also lifted the bike on it's center stand, gave the motor a little spin and checked the cells. All came in at 6.56 or 6.57 volts a pair. I'd call that pretty well balanced.

What's wrong with Top Balancing

Let's go over the basics again. Top Balancing is based on a belief that you can fully charge a cell by charging it to a certain voltage, say 3.65 volts, and just keep it there. To get a complete pack "balanced" would require to charge until all cells are at 3.65 volts. To do this some cells need to be kept at 3.65 volts while others catch up. That's all part of Top Balancing and what many BMS do.

So how did they come up with this system that many people swear by and even think to be absolutely necessary? They probably don't know themselves, but here's how I think it must have happened. We know that a LiFePO4 cell likes to stay within a certain voltage range. Go below 2.5 V and you start hurting the cell. Go above 4 V and you're definitely hurting it. To charge a battery you put current into it and since you know you don't want to go over a certain voltage you stop when it's reached. This was 4.2 V in the beginning, but I guess they've found it a little too high since 3.65 V is what most recommend now. They also found out that if you taper the current you can put a little more energy into the cell while keeping the voltage at 3.65 V.

Now think of Lead Acid for a moment. In Lead Acid voltage is voltage and voltage is charge level. You charge and you keep trickle charging your Lead Acid batteries, they'll be happy for it and you get a nicely Top Balanced Lead Acid pack. The more energy you can put into them the happier they are and the more range you will get from you Lead Sled.

Now if you put these two things together, maximum charge voltage and Lead Acid heritage, what you get is Top Balancing and what usually is considered to be a Lithium BMS. To prove this they talk about stuff like Cell Drift and Self Discharge. I really don't know how they came up with them, but it must be from Lead Acid heritage as well. Or maybe they put this Top Balancing BMS on their cells, kept recording the voltages and noticed that they vary and the cells will Self Discharge.

What they didn't think of was that they had the BMS connected the whole time and both phenomena were actually caused by the BMS itself. If you put any Cell Level system on your cells that's not very, very carefully designed not to draw any (and I do mean any) current, you will see the cells react and they will react differently. You will place on uneven load on the cells that will cause "Cell Drift" and the load itself will be the "Self Discharge" you see. To make matters worse, if you Top Balance and keep cells at 3.65 V while other catch up, you will damage your cells and damage them by different amounts, which will only inflate the problems you think are caused by the cells themselves.

But what about internal resistance, you ask. What about it? What part of Top Balancing BMS will have any effect on the internal resistance of the cell? Yes, the cells may have varying internal resistance and that variation will cause them to discharge at a different rate. Let's say you have a pack of cells and you'd charge them each individually to 3.65 volts without damaging them by "boiling" some at that voltage while others catch up. You'd end up with fully charged cells, right? Now what happens when you start discharging them as hard as you can? You know they have different internal resistance and slight variation in capacity, because they just can't make them perfect yet.

So you're discharging and discharging and your first cells hit the cut-off voltage. You have to stop now, or you'll damage those cells. And you'll better be quick about it too. Stop the car immediately. If you were smart you had already put the vehicle into a Crawl Mode, so that you could pull over safely. Unless you've kept a really good track of previous full discharges you won't know when your first cells will be empty and when you should start crawling. Doing so gets really complicated and expensive really fast. Add in all the single cell level monitoring, shunts to enable Top Balancing and it's not really hard to imagine why those BMS systems are so expensive.

Hopefully I've by now convinced you of the problems with and caused by Top Balancing. I'd really like the whole world to get a clue on this, including Boeing and the BMS people at Sähköautot - Nyt! forum, but I don't have my hopes up. What's amazing is how firmly rooted these false beliefs are. It may just be that a lot of people have too much invested in BMS systems to admit there are issues. It sure does seem like a lot of people are looking to make a buck on these.

I guess I still have the obvious question unanswered. If Top Balancing doesn't do what people think it does and if it doesn't really solve anything, what is the answer? How about if we try something quite opposite. Instead of trying to Top Balance the cells we drain them as empty as we dare. 2.5 volts is a little dangerous so let's say 2.75 volts. Let's call that empty, or close enough.

Now if we have all of our cells empty and we connect them in series with just the interconnects we have an empty pack. What happens if we charge them? They will all receive the same amount of current. They're all a little bit different so they absorb their share a little differently, but it doesn't matter. We don't like any cells to go above into dangerous territory so we undercharge a little. We don't even pretend to get all cells at exactly 3.65 volts. Most end up a little below and some may even go a little higher, but it doesn't matter. We accomplish this by charging the whole series pack to cell count times 3.5 volts. My experience is that even with this undercharge you will end up putting as much or even more energy into the cells than what they are rated for.

What you've in essence accomplished by this Bottom Balancing is that you've zeroed all the differences between the cells, whether it be capacity or internal resistance. When you discharge the cells they will do the same thing in reverse that they did when you charged them and if you keep discharging them they will all end up at the same voltage you Bottom Balanced them at. In other words they will both charge and discharge very close the same way. Close enough that it doesn't matter. As a bonus you don't have to keep track of your cells. You'll now exactly how many Ah went into the pack when you charged it and you know exactly how much you can take out. And once those cells hit that 2.5 volts, all together, at the same time, they will be putting out hardly any energy at all. And since they're all empty they can't force each other into destruction.

Disclaimer: All of my battery ramblings are based on my own experience and Jack Rickard's findings. They are applicable to CALB SE- and CA-series cells. Other cells and chemistries may at least require different voltages.

Hint of progress

The really bad, quick and dirty cell phone photo above depicts the current state of affairs at the kWsaki EV conversion industries. A very kind forum member from the VMPK forums sent me a 350 mm disc of about 17 mm thick aluminium that I was (barely) able to drill a few holes into. Only destroyed an electric drill in the process of making that big hole in the middle, but hopefully I can make this work. Next I'll have to figure out the coupling between the motor and the flywheel. I intend to keep the clutch as a safety feature, if nothing else. Don't worry, I'll make it look all pretty and black eventually.

Update: A coupler pictured here is now on order!

Cell drift

Or lack thereof. Yesterday, when the thermometer showed 0 degrees Celsius (or 32 Fahrenheit), I figured it would be time to go check the cells in my kWsaki electric motorcycle. I took the bike off insurance October 3rd so it's been sitting in the cold garage for about four and a half months. I gave one of the TTL-200C motors a quick spin with the kWsaki traction pack and controller, but I haven't recharged since October.

And when I said cold I meant it. The temperature here has regularly been below zero Fahrenheit and the cells have had to endure it. So I was a little excited when I started the measurements. First cell 3.299 V, second 3.299 V, no make it 3.300 V, next 3.299 V, 3.300 V, 3.300 V and so on. It got really boring really fast. I got a little bit of variance when I couldn't reach the terminals of a couple cells and I had to measure them in pairs. They read 6.61 V. A couple cells showed 3.31 V. This was after I had changed the meter's resolution from 0.000 to 00.00. The whole pack registered at 82.8 volts. For 25 cells that's 3.312 V each.

Considering that the meter is no Fluke and it showed a maximum variance of hundredth of a volt, I don't see evidence of cell drift. I've had nothing connected to the pack for these last months. Note that this is the same pack that I pushed down to 2 volts per cell earlier. If I had damaged any of the cells, they probably wouldn't be happily floating at 3.3 volts after being left to their own devices for months.

Conclusions are that cell drift has not been demonstrated and bottom balancing still seems to work.

If I had more money than I can spend, I could have gotten another 25 cells, put a MiniBMS on them and let them idle for over four months. Alas I do not, but the result is easy to guess. Anyone care to prove me wrong?

The Shopping List

You may or may not find this interesting, but here's my shopping list for the car as of now.

Already got for the initial build (some of these may get upgraded later):

• Thrige-Titan TTL-200C motor
• AXE7245 90V 450A controller
• KP-L 2000W 87.6V charger
• 0-5k throttle
• 25pcs CALB SE40AHA 40 Ah cells
• Cycle Analyst instrumentation

On order at this time:

• Nothing

High priority items needed (car won't run without):

• Another 25pcs of cells (CALB 40, 60 or 70 Ah, preferably CA-series)
• Motor cooling (EVTV BlowMe or something else)
• Main contactor

Low priority items needed (car won't pass MOT without):

• JLD404 or similar voltage meter for main contactor activation
• DC to DC converter
• Auxiliary 12 V battery
• Vacuum pump (very important)
• PTC or liquid cabin heating (liquid is actually easier, but more expensive)
• High voltage warning stickers everywhere

Vanity items:

• ELECTRIC emblem of some sort
• Braided straps for cell interconnects for improved durability

The list may be incomplete and/or outdated. Just like me.

How To Bottom Balance

Warning! This article is about LiFePO4 cells. Some of it may or may not apply to other chemistries.

My earlier post on bottom balancing was long and mainly about why to do it. So I figured I might do a little step by step for those who just want to get it done without delving into the philosophy behind.

1. Drain all of your cells down to 2.75 volts. Note that the cells will bounce back after you disconnect the load. Repeat the discharge until each cell standing alone stays at 2.75 V.
2. Connect your cells to each other. Do not connect anything else between the cells but the bars, straps or fuses connecting cells to each other. Do not install BMS. Do not connect any other wires. Strictly cell interconnects only.
3. Charge the battery pack to a voltage of 3.5 to 3.55 volts times cell count. Examples: 25 cells = 87.6 volts = 3.50 per cell, 33 cells = 116.8 volts = 3.54 per cell. Use CC/CV profile which is the default in many LiFePO4 chargers. End charge when total voltage is reached.
4. Always discharge the pack as a whole. Always charge the pack as a whole, the same way as described above. Never put any load on only a part of the pack, no matter how small. Never install cell level monitoring or BMS which put any load on individual cells.

If you do this right you shouldn't need to repeat it. If you want, you can periodically drain your pack and measure the voltages. They should all be about the same. If you notice irregularities they are most likely caused by bad cells. Replace bad cells and repeat the bottom balancing for the whole pack.

Bottom balancing is not negligence. Bottom balancing is utmost cell care. You drain them one by one, manually or with a device like Revolectrix PowerLab. While you do that you will spot bad cells quite surely. When you charge them you end the charge well before overcharge and the charge is controlled by the one device which does it best, the charger. As an extra precaution you may also consider adding a meter which disengages the main contactor if pack voltage is not within limits.

On discharge you set your controller to a low voltage limit of over 2 volts per cell (for example, 60 V for 25 cells, 80 V for 33 cells, perhaps even lower). This will prevent any cell going too low, since they all empty at the same time. Since they're all empty they can't harm each other.

Fires happen when cells get overcharged. Bottom balancing doesn't cause overcharging.

Disclaimer: All of my battery ramblings are based on my own experience and Jack Rickard's original work on the subject. They are applicable to CALB SE- and CA-series cells. Other cells and chemistries may at least require different voltages. I take no responsibility for any problems or damage caused by anyone.

All Quiet on the Western Front

I've been keeping busy with other parts of life, hence no blog posts on EVs in a while. Also I have the car mostly outside, albeit under covers, but still in either bloody cold or nasty damp weather. No warm, dry garage for me at the moment. I have the motorbikes in the garage, but it's still cold.

It doesn't mean my brain has stopped working though and I've been thinking about the projects a lot. I even got around to making some inquiries on the possibility of obtaining some aluminium for the motor adapter plate. Turns out nobody has anything in storage, ordering costs more than actual material and aluminium isn't cheap either. There goes my plan of buying some and playing around with it.

That means it's back to the CAD program and having everything made somewhere based on my drawings. For some reason that also has near zero attractiveness at the moment. Someone on a Citroën forum did point me in the direction of a PSA XU engine brochure which included a priceless picture of the motor with proper measurements and angles of the transmission facing bits. Will make my life a lot easier with the CAD, as soon as I can get around to it.

Reprinted without any permission whatsoever.

I also find myself thinking about battery placement in the kWsaki and dreaming of doubling the amount of SE40AHA cells to get to the 80km+ range I originally had in mind. I think it will happen during spring/summer as well. The kWsara also needs more batteries to move anywhere, so the additional cells will double as both cells for the kWsaki and testing the kWsara.