openinverter forum

I wouldn't right off the gen2 transaxle until someone tests with both motors.

the mg2 winding in each coil contains 8 turns. it would be changed by 5 turns with an increase in the phase cross-section, I am sure that the motor will turn out no worse than the Nissan one.

I got the ebay LCR module. It has 3 pads which i soldered fly leads to.

As suggested i joined two of the mg2 phases together and attempted to get an inductance reading from MG2 using two leads from the module across the looped pair, and the single phase. I rotated the motor a few times. (Does it matter which leads i use on the test module, i assumed not.) However I only got it once to display a mH value, the rest of the time it stated two diodes.

Am i operating it correctly ?

Afraid I'm not familiar with that particular LCR tester but there is normally a way to force it into either L, C or R mode. You will need to force it into incuctance (or L) mode to get sensible readings off the motor. @Bigpie may be able to advise how to do this?

Have you got any other inductors, caps or resistors that you could use to test the meter is working ok?

I put one jumper wire in the top left of that levered connector, and the second wire in the top left +1. First jumper to 1 phase, 2nd jumper to the other 2.

Jack Bauer wrote: ↑Fri Nov 11, 2022 8:45 am I wouldn't right off the gen2 transaxle until someone tests with both motors.

I like your optimism

I'm not writing it off even with just MG2. Of course 28 kW isn't very performant but as a small commuter car it'll do. Heck, people used to drive around with 15 hp. Also the motor is barely heating up, so we're not pushing it here.

On a side note I'll do a first TÜV visit on Wednesday.

28kW will maintain 100km/h on flat road even in a loaded van. Some people aren't looking for performance but rather low price, low weight or space efficiency. 28kW would be just fine for my MGR project. There's hoping it performs about the same.

ok -using the technique described above i took about 20 readings.

The lowest being 2.36mH and the highest single reading 6.1mH (bit of an edge case as the highest generally were in the 4.3mH range)

hope this helps with some calcs

Seems similar to Gen2 MG2 then. I reckon they must have reduced flux linkage (the rotor is just half as long) to run at higher speed.

I drove to Göttingen TÜV station today because the weather is nice and it is supposed to rain on Wednesday. Trip went beautiful and consumption seemed rather low. Started with 90% and arrived with 53% and drove 50 km.
Not sure how to interpret it. The BMS reports SOH=74% (it is from Zapateros very used 24 kWh pack). So then I reckon the Coulomb counting is based on 0.74*24 kWh=17.8 kWh? In that case I would have used 0.37*17.8=6.6 kWh or 13.1 kWh/100km. Sounds plausible actually.

It's possible that the changes may have improved efficiency a little. The old mtpa did generate more Id than was needed and the new syncadv better controls the id and iq; both of these could help efficiency. Do you have any before data from a car to allow a direct comparison?

As someone with a limited battery capacity any improvement to efficiency would be great news

Don't have data from the Audi but on Touran I see improvements, too. Gotta test it more systematically though.

FFMan wrote: ↑Mon Nov 14, 2022 8:28 pm ok -using the technique described above i took about 20 readings.

The lowest being 2.36mH and the highest single reading 6.1mH (bit of an edge case as the highest generally were in the 4.3mH range)

hope this helps with some calcs

Thanks for those, they do look pretty similar to the Gen2. Did you take any measurements on MG1?

Hopefully this isn't venturing off topic too far, but Johannes's experience has me wondering about viability of my P410 box in a conversion. I realize these are a bit different than the P112 - less powerful, but more RPM and multiplied by more gear. I considered if I undertook something front wheel drive and if this were not to my tastes to just develop it with a different option. Considering a VW or Mini as the basis since they are plentiful and inexpensive locally and also lightweight. Donor candidates are $1000 USB any day of the week.

My local pull-it-yourself type yard regularly has Camry Hybids in stock and therefore laying my hands on a P310 for $120 USD would be quite easy. I'm wondering if these are a significant enough upgrade over the P112 to consider this for a conversion instead. For my personal tastes the performance is a big factor, but I'm also plotting my first conversion to manage costs as much as possible.

Any general wisdom on the P310 vs. the P112?

I would say any of the Toyota/Lexus transaxles could be viable for a conversion, the biggest problem being to get the rated power and high enough rpms for a decent road speed that you need a higher than normal battery voltage, as Johannes has shown the new software has sufficient field weakening to get decent road speed but the power level is low thanks to battery voltage, in my head I’ve been toying with the idea of doing a build than would use 2 300v nominal batteries in series in drive mode but would separate and parallel them for charging…. If look to use maybe a Lexus rx400h or maybe rx450h inverter as they are rated for 650v dc bus. Just ideas at this point

And another early forum release. Turn on subtitles if you don't understand Deutsch

one question, isn't the power wires at the bottom of the car dangerous? there is a mine from the exhaust system nearby, why not spend them there?

Romale wrote: ↑Thu Nov 24, 2022 10:13 am one question, isn't the power wires at the bottom of the car dangerous? there is a mine from the exhaust system nearby, why not spend them there?

I agree. There was request from TUV Sud to protect cables and connectors under the car from moisture and debris. I resolved this by putting them in the exhaust channel and cover that by alu sheet.
However the latter cover is not compulsory as long as cables are on the outside of the chassis. I think there is a german national standard and they do not insist on any cover directly from the underside.

Why does everyone get so worked up about these cables? The fuel lines used to travel along that same route, I'd consider that far more dangerous than HV cables that at least don't leak a flammable liquid should they ever get damaged.

johu wrote: ↑Thu Nov 24, 2022 4:11 pm Why does everyone get so worked up about these cables? ....

because we are worried about you))

Romale wrote: ↑Thu Nov 24, 2022 10:13 am one question, isn't the power wires at the bottom of the car dangerous? there is a mine from the exhaust system nearby, why not spend them there?

I ran power cables inside plastic sill. There is lots of space there.

Finally some more progress to report.
Thomas, the owner of the Audi, came to visit for 3 days. Our main task was to move the transmission further backwards to straighten out the driveshafts.

In order to move it backwards, we also needed to move it to the left to avoid the steering column. Moving to the left meant the driveshafts would no longer fit. But then my genius neighbour came around and asked "what if you swap the drive shafts right to left?" And indeed, the length difference turned out to be only 70mm. So swapping them meant we could move the transmission 70mm to the left. And that meant we could move it backwards by up to 80mm. Winner!

The setup looks a lot neater now. We gained enough room in the front to fit the stock radiator fan (needed for A/C) and it's just generally less crammed.

We left off with everything back in place except the torque arm. That will need some parts machined.
Also the left hand (as on photo) mounting of the cross member will receive another bracket to use the other two bolting points.

Hi Johu,

is there somewhere that you have tabled your optimum MG2 parameter values?

Kind regards,

Johnspark

johu wrote: ↑Mon Nov 14, 2022 1:07 pm I'm not writing it off even with just MG2. Of course 28 kW isn't very performant but as a small commuter car it'll do. Heck, people used to drive around with 15 hp. Also the motor is barely heating up, so we're not pushing it here.

On a side note I'll do a first TÜV visit on Wednesday.

From this site shared previously:
http://roperld.com/science/Prius/PriusPhysics.htm
Using this Torque/RPM graph I 'roughly' converted this total Nm (MG2+MG1) to power/RPM graph.
You can see constant power region from 1500>rpm is around 95hp - 70kW! Splitting out the 'approximate' power curve of MG2 and MG1 - MG1 can contribute 25-30% additional power so is an substantial benefit.

New torque arm connection
Rubber bushing gets a bit of a bend but think that'll be fine