openinverter forum

Wow, i actually do not have a key or ignition lock in my project and was thinking of leaving it out, another thing to think about..

So I removed the ignition barrel on Tuesday with the extra excitement of having to remove the airbag - to be able to remove the steering wheel - to be able to remove wiper and indicator switch - to be able to remove the steering assembly ECU - to be able to remove the ignition barrel

Found some good youtube videos on that. Of course the ignition barrel is bolted on with screws that sheer of their head when mounted to make it harder to remove. But with a fresh chisel they can be given the initial turn and then come out easily.

Of course the official key cylinder removal technique doesn't work: turn the key like 80% and then get in there with a paper clip. Well if the key only turns 30%... I used a cutting disk instead.

So now I'm waiting for the new ignition barrel, put the original key cylinder in that and put everything back together. With normal screws!

Das auto for you.... Seen a few in my time working in vw garage. Quality
I'm sure you taped up that nice spiral sensor so it goes back in same position

I have one of those headless screws on my T2. I bought a set of "easy-out" extractors this week... Wish me luck.

Just like that, it's done.

A rare example of an EZ-out actually working!

Left handed drill bits are much less likely to snap off and make the extraction even harder.

Ok, everything back together and car is running again

Also replaced the noisy fan in my Meanwell power supply by a much quieter Papst one. It does produce less airflow though, have to watch it closely should there be another hot day this year.

RetroZero wrote: ↑Thu Aug 27, 2020 8:40 pm I'm sure you taped up that nice spiral sensor so it goes back in same position

Erm... no but it didn't move while umounted.

DaveH wrote: ↑Fri Aug 28, 2020 10:08 am I have one of those headless screws on my T2. I bought a set of "easy-out" extractors this week... Wish me luck.

Yes bought one of these tools as well but before it arrived here I had the screws out with the chisel. Which is good, because my Makita doesn't quite fit in the confined space.

Now as temperatures swing a lot between morning and afternoon I found a small issue with the way I operate the fuel gauge. Basically it is run with 2 NPN transistors that simulate a varying resistance. When they both simulate, say 50 Ohms the gauge is in the middle. If one simulates 25 and the other 75 Ohms it would be at 25%. The gauge cluster expects some 100 Ohms total and there is an adaption channel to set this up to 130 Ohms. In other words, it is a bit sensitive when total resistances deviates from 100 Ohm.

And thats exactly what happens when the temperature of the transistors changes

So say you calibrate this to work at 10°C ambient the gauge will detect a value out of range at like 30 or 40°C ambient and will not move! I faintly remember this is usually solved with some 10 Ohm resistor between emitter and GND. Would this work here? the chain is like STM32 PWM -> 10k -> 1u to GND -> transistor base.
Or otherwise I could vary the two relevant parameters with temperature...

johu wrote: ↑Wed Sep 02, 2020 8:40 am Now as temperatures swing a lot between morning and afternoon I found a small issue with the way I operate the fuel gauge. Basically it is run with 2

I had similar problems with gauges.
I solved it with using the original driver electronics, it should come from a microprocessor or something similar.
Maybe 5V/3.3V PWM
I guess it's not coming directly from the gas tank measuring thing?

Do you have a schematic of the fuel level sender connected to the cluster? Is the sender a 100 ohm pot with one end and the wiper connected to the cluster (2 wires)?

The "gas tank measuring thing" is just a pot. The wiper is grounded and the two ends are connected to the gauge cluster.
The pot is connected to a controller and that controller is connected to the gauge cluster. I'm thinking all it used to do was switching the fuel pump on and off. See attachment.

johu wrote: ↑Wed Sep 02, 2020 11:09 am The "gas tank measuring thing" is just a pot. The wiper is grounded and the two ends are connected to the gauge cluster.
The pot is connected to a controller and that controller is connected to the gauge cluster. I'm thinking all it used to do was switching the fuel pump on and off. See attachment.

Would you care adding the code to github? I would like to try to solve my PWM SOC signal.

tnx

It sounds like you need some feedback to measure the current each transistor draws and correct your pulse width to compensate. The gauge expects to see a certain currrent range depending on the resistance. You could use a small resistor on the emitter like you say, to measure the current. There is a downside that this gives a minimum effective resistance (when the transistor is on 100% of the time) of say 10 ohms, so your gauge will never read completely full or empty.

DaveH wrote: ↑Wed Sep 02, 2020 1:15 pm It sounds like you need some feedback to measure the current each transistor draws and correct your pulse width to compensate. The gauge expects to see a certain currrent range depending on the resistance. You could use a small resistor on the emitter like you say, to measure the current. There is a downside that this gives a minimum effective resistance (when the transistor is on 100% of the time) of say 10 ohms, so your gauge will never read completely full or empty.

Yes will try that. I described a bit wrong. In fact the middle duty cycle is 1250/4096 and 1.8 digits are added for each % SoC. So minimum value is 1250-50*1,8 and max is 1340 digits accordingly. So full on PWM isn't nearly needed. I hope the negative feedback of the emitter resistor is sufficient for compensation. Higher current -> higher voltage drop accross resistor -> higher emitter voltage -> lower base-emitter voltage.

arber333 wrote: ↑Wed Sep 02, 2020 12:25 pm Would you care adding the code to github? I would like to try to solve my PWM SOC signal.

It's already there in the stm32-car project.

You might need to reduce your base resistor to get enough base current, but as long as the base is > 0.7V higher than the emitter when your PWM output is high, it will work.

regarding your last Video on YouTube i want to leave a few of my numbers here:

I did some 60 to 80km test drives and checked the consumption by hooking it up to the public AC charger. That tells you exactly how much Kilowatts it has charged into the batteries as one get's billed by that. I pretty much always end up around 20 Kw/h of energy consumption. I drove about 60km on rural roads and 20km in the city. I guess it's the same like with an combustion engine that the consumption is higher in city traffic as if you travel on rural roads or at constant highway speeds.

One more Touran trip, one more adventure Drove to a place near Fulda, 120 km one way. First stop at fast charger in Kirchheim, ChaDeMo marked as "60kW". So plugged in and indeed it charged at 53kW for a while After 20 minutes we were good to go.

On the way back another charge stop at a VW dealership. Lots of questions from staff - they know theres no such thing as E-Touran

Back on the Autobahn we heard some vibration. Not too bad but something to be checked. I was gonna charge again at Kirchheim anyway so while the car was charging I checked around. 4 out of 6 drive shaft bolts had come loose! So while the car was still charging I walked around looking for a garage. Finally found one with some guys sitting outside zipping their beer. Seemed like the right place.

They lent me tools and even let me use the lifting ramp. Fastened the screws and away we go

Still, not a problem with the actual conversion. But of course this time I was the problem because I probably didn't fasten the bolts sufficiently.

More amazingly, the consumption on our way to Fulda was like 20 kWh/100km even though I was going just 110 km/h. The reason showed on the way back. Even though I was going 120 now, consumption was just 16.5. Seems we gained quite some elevation on our way there.

Next long trip is next week, lets see which surprises Touran has then

I had the same problem with driveshaft bolts in der panzer. Red thread lock is your friend:) Sounds like a great adventure. I especially like the calling in at the dealership. Gives me an idea. BMW Ireland are offering a free "get ready for winter" checkup

Do it
I reckon I should get rid of the grease on bolts and thread before applying thread lock?

Jack Bauer wrote: ↑Wed Sep 09, 2020 6:51 pm Gives me an idea. BMW Ireland are offering a free "get ready for winter" checkup

ROFLMAO!!!! Have them check the belts and load-test the battery, that'll be good for a laugh

johu wrote: ↑Wed Sep 09, 2020 7:40 pm I reckon I should get rid of the grease on bolts and thread before applying thread lock?

LOCTITE® 2400 Datasheet - "For best results, clean all surfaces (external and internal) with a LOCTITE® cleaning solvent and allow to dry"

https://www.farnell.com/datasheets/2600329.pdf

Just use some Nitro solvent on the bolts and clean the threads with a paint brush.
When you apply thread retaining compound you want to dose it across the threads not trying to fill all the grooves.

So, long drive again yesterday Of course Touran had surprises, but to that later.

First of all I did some logging. The data logger played up when left at the default setting of 500 values per line, setting this to 100 yielded better results. So I have one log driving the battery from 77% to 17%. I pulled 19.6 kW on average in 38 minutes. So 60% state of charge delta yields 20.5 kWh of usable energy.

When charging from 26 to 68% I got 34 kW average charge currents over a timespan of 16 minutes. SoC delta 41.7% yields 21.9 kWh usable energy.

It was a very hot day and battery temperature peaked at 53°C !

Now, the surprises.
I was stuck in congestion for about an hour. Luckily. So the sort of full stop congestion where people start walking their dogs. I was in the car with ignition on listening to radio. Suddenly, BEEP! - check coolant. So I did and indeed the car had become source to a small creek flowing down the Autobahn. Opened the hood and the de-airing pipe had come off. Pump diligently emptied the fluid through it. Every bit of negligence gets you some day. Thank god this didn't happen while driving.
So the man in the car before me thankfully gave me 1.5l of water. Refilled the reservoir and massaged the pipes to get the air out, hoping for the best. I drove very carefully to not overheat but nothing happened.

Next surprise. When I was almost at my destination I had to charge one last time. Plugged in the charger for the 4th time that day, start the session and... stop. "Charging terminated by vehicle". Ok, try again. No. Ok pull the plug, try again. But wait, the red light is still on. Hmm. No, plug doesn't come out. Call the hotline to have them restart the EVSE. Red light still on. Whenever I call these hotlines I tell them I have a Nissan Leaf to avoid them blaming the car prematurely.
Well, finally I had to tell the lady "well, actually it's not quite a Nissan Leaf". Ok, disconnected the 12V battery in case the car might somehow be energizing the plug lock. No. Finally got desperate, removed the seat, removed the carpet, go to the charging logic and unplugged the charge relay cable. Red light OFF! yes! Can pull the plug.
Now I connected the rich mans 3-phase charger and indeed charging worked from the Type 2 connector (thanks Arber for that adapter, it works a treat!). Meanwhile my dad had arrived as I'd called him for rescue. That was very re-assuring to I unplugged the AC charger and tried ChaDeMo one more time. It worked!

Now I'm still not sure whether this was the EVSEs or the vehicles fault. I do lean towards the vehicle as it's less proven. The charging logic sits right on top of the battery and, like said, that was really hot.

Anyone experienced that before?