Skoda Octavia Estate 2001

[Maker_of_Things]

My project:
I have a Skoda Octavia 1.9TDi Estate, which has been my most idea car format since I bought it new in 2001. But it has been driving around for about 7 or 8 years with a failing turbo and intermittent limp mode. My wife, Sue, has been using it as a local driver since I bought an Octavia Scout, to keep working with for the time being.
The Octavia has a few electrical niggles that I can live with, and the usual body scrapes of a hard working vehicle of its age.
It has 240,000 miles on the clock and has passed all MOTs with only minor issues and has a full service book.
When we saw Lockdown coming we put the old Octavia on SORN and I think it is time to convert it to electric now.

What I would (ideally) like:
I want to keep the load space completely clear of any conversion stuff as I want to use the space for work.
I want to keep the 1300kg towing capacity.
I want to keep the spare wheel and tools under the boot floor.
Range: minimum 100 miles on a bad day (or a good day carrying a load).
Top speed: 70mph loaded/up hill.

However, my budget is small especially given the reduced income at the current time.

I am hoping I can do this, with a lot of advice and guidance, so I can finally scratch that itch that has been keeping an ongoing EV project of some description going for some 15 years. (And yes, I still have another personal, DC based, EV project on the back burner to use up the DC motors and controllers I have. )

Thank you,
Alfred

[bobby_come_lately]

Glad to see you're making a start on this!

[Maker_of_Things]

Cheers.

Still thinking about the Kei truck option but also why spend money on bringing in a truck when I have my 'truck' already!
Also the Octy is worth nothing on Ebay, but worth more to me then a tiny flatbed.

I need to decide on a progress plan, also how to safely drain out a full tank of diesel to put in the Scout.

[johu]

When on a tight budget I suppose a 30 kWh battery should get you your 100 miles / 160 km. I use 24 kWh in a Touran and it will do 120 km. As it's a rather tall car I suppose the Skoda will get better mileage and the extra 6 kWh should at least get you close to 160 km.

Any modern EV drive train should be able to go 70 mph up hill. For obvious reasons I like the Nissan Leaf drive train a lot

EDIT: check this out: viewtopic.php?f=11&t=372

[Maker_of_Things]

Cheers Johu,

I have been trying to decide what to use and what is most easily supported by Open Inverter control.

I have been looking at the Lexus type diff/motor unit for its small size hoping to save space in the engine bay for inverter and batteries. But until I get things apart I don't really know what space I have.

Also working outdoors (on a sloping cobble drive) means I sorta want as close an idea as possible before I strip the car down to being too immobile.

[Kevin Sharpe]

I am hoping I can do this, with a lot of advice and guidance, so I can finally scratch that itch that has been keeping an ongoing EV project of some description going for some 15 years.

Welcome Alfred

Is this FWD or 4x4? Automatic? ~100 hp?

Can you give us some idea of your max budget?

[Maker_of_Things]

Hello Kevin,

My Octavia is a front wheel drive, 5 speed manual, 110bhp.
It's the Elegance model with all the (non functional) bells and whistles.
Air con dead
Central locking dead
Sunroof dead and taped up to stop leaks
Electric windows sometimes open themselves if it is raining
Drivers door lock dead
PAS works though....
Most of that either can be fixed, or doesn't matter to me.

I don't need sporty acceleration, just enough to not hold up traffic (I drive like an old man).

It is mainly used for carting my tools around to local jobs and taking crap to the tip but most of the paying work seems to be 50 miles away with no recharge opportunities due to time constraints, so 100 miles gets me home. It also gets us to the MiL for Christmas...

[johu]

Also working outdoors (on a sloping cobble drive) means I sorta want as close an idea as possible before I strip the car down to being too immobile.

Sounds familiar

Good thing the aircon is dead already. I felt bad ripping the working one of the Touran out. Plus I find it difficult to get going again.

Regarding "time constraints" a quick charge port works wonders and isn't hard to implement. I almost couldn't believe seeing 50kW going into the battery on my first long distance trip. What this means is 12.5kWh in 15 minutes which would probably yield like 80km in an Octavia.

[Kevin Sharpe]

My Octavia is a front wheel drive, 5 speed manual, 110bhp.

Thanks for the information. I'd look seriously at a Toyota Prius transaxle. While the Leaf motor is another option it's a lot more expensive and I'd rather spend the money on batteries

[celeron55]

To tow 1300kg, you need lots of torque at the wheels to get up hills. For that a single Lexus rear diff will be totally incapable, it's geared way too tall. If you use them, you need to do 4WD.

Personally I think for towing (or any other low budget high performance application) you should keep the original manual transmission. That way you can select a lower gear when towing and the end result will be more capable than the original ICE.

When keeping the spare wheel, all of the cargo space and I'm assuming all of the rear seat intact it will be almost impossible to get a 100 mile "bad day" range. You probably have to use the best batteries money can buy. You might have to use Tesla modules, but using only 6 or 7 of them will result in an unusually low voltage which will lower the available rpm and power from scrap yard EV components. And of course will make it impossible to DC fast charge.

[Maker_of_Things]

Sounds familiar

Good thing the aircon is dead already. I felt bad ripping the working one of the Touran out. Plus I find it difficult to get going again.

Yes, having nothing working does mean not needing to keep it working.

The main thing we do for work is that we make a piece of furniture, or a prop, deliver it with maybe a very quick install to a museum or visitor attraction, and then run away quickly because there is no parking, or just a loading bay.
If we have to park then it is the very nearest car park, due having to carry stuff, and the ones we have been using or are nearby don't have charge points. Finding one and getting back to the job on foot takes longer then the job.
Easier to just charge at home.

One day there will be chargers everywhere a vehicle can park, and I will have a cheap work van with a 400 mile range!

[Maker_of_Things]

My Octavia is a front wheel drive, 5 speed manual, 110bhp.

Thanks for the information. I'd look seriously at a Toyota Prius transaxle. While the Leaf motor is another option it's a lot more expensive and I'd rather spend the money on batteries

Thank you, I will do this.

[Maker_of_Things]

To tow 1300kg, you need lots of torque at the wheels to get up hills. For that a single Lexus rear diff will be totally incapable, it's geared way too tall. If you use them, you need to do 4WD.

Personally I think for towing (or any other low budget high performance application) you should keep the original manual transmission. That way you can select a lower gear when towing and the end result will be more capable than the original ICE.

That make sense to me. But also open to looking at ways to reduce the size of the package to allow more space under the bonnet for the rest of the conversion, and maybe some of the batteries. I am so unfamiliar with the amount of space current (no pun intended) EV stuff takes up.
However, I could scrub the towing if I have to and just use my Octavia Scout for that until another option comes along later.

When keeping the spare wheel, all of the cargo space and I'm assuming all of the rear seat intact it will be almost impossible to get a 100 mile "bad day" range. You probably have to use the best batteries money can buy. You might have to use Tesla modules, but using only 6 or 7 of them will result in an unusually low voltage which will lower the available rpm and power from scrap yard EV components. And of course will make it impossible to DC fast charge.

OK. I'm willing to give up the towing, or reduce it to my small 350kg trailer, but I can't really reduce the load space and seating inside.
Also the spare wheel is always a concern. I've only had 2 punctures but sods law will say that if I don't carry a spare I will have a major blow out in the middle of nowhere! (Well, one has to keep some traditions!)

I may just have to live with best range I can afford and rethink stuff around charging to and from job sites.

These are the things that concern me with the project. If I spend £7-8k+ on this as a budget conversion, and then maybe looking at £5k on compliance inspection, and still have a vehicle that has compromised load space and sub 100 mile range, I might as well buy an old Leaf as a local 'shopping car' and carry on using my Diesel Octavia Scout for work. But if I am using the Scout for work then a Leaf is more car then needed the rest of the time.

It is all balancing usage and trying to push as much of my major car needs to electric as I can.

[RetroZero]

The cheap way is Prius transaxle, but no real pulling torque.
The ideal option (in my humble opinionl) is a Leaf motor fitted to original gearbox. I worked for VW & Skoda, the setup of Johu is pretty much what you need, no re inventing the wheel. Would save you lots of time and hassle...don't forget, your cars CAN communication would be similar along with engine and fuel tank arrangements. There's BMS and charging to think about, again, pretty identicle to Touran...
Unfortunately, cheap and ideal don't normally go together, but plenty options are available now.

[johu]

Yes the Touran is pretty much what you would need. It would have strong towing capability (had I not bought one without tow bar), I fitted an entire Leaf pack where the fuel tank used to be and still have lots of space under the bonnet that is currently unused. Interior space is not touched at all and also the spare wheel is still there. Only deviation from your requirement is the 70 miles of range but that would be easily fixed with a 30 or 40kWh Leaf pack which has the same volume.

That said I don't know how many batteries, if any, would fit in the fuel tank region of your Octavia. If you fit half what I fitted you could still use the engine compartment for more.

Concerning charge stop I didn't mean the place where you unload but shortly before or after your destination.

[jap]

With your budget I would look at Leaf with a battery upgrade. I dont think you can tow 1300kg with it, but for lighter loads it seems pretty efficient according this guys experience:
https://ecomodder.com/forum/showthread. ... 36473.html

For heavier towing I think you absolutely need gears like celeron55 and RetroZero said. Problem is where to put enough battery on your car (40kwh for your needs at least). Exhaust tunnel etc could be used, but that means customizing either the pack or car, both options are tedious and expensive.

[Kevin Sharpe]

no real pulling torque.

For heavier towing I think you absolutely need gears

AFAIK we have no evidence for these statements. On today's EV course we assembled a welded Prius Transaxle and hope to spin it up with a Toyota inverter tomorrow. Damien will be testing it in a car in due course and I suspect it will perform admirably.

The OP has a limited budget which really does not stretch to a Leaf based solution.

[Kevin Sharpe]

It is all balancing usage and trying to push as much of my major car needs to electric as I can.

The Leaf motor is really over powered and priced but I'm sure we can find a solution that meets your performance and budget requirements

https://twitter.com/NewElectricIRL/stat ... 13793?s=20

[Kevin Sharpe]

I'm sure we can find a solution that meets your performance and budget requirements

We'll need to do more work but it's not unusual to find dual motor Prius transaxles for 100 GBP;

https://www.ebay.co.uk/itm/TOYOTA-PRIUS ... 2857485964

Prius inverters for 100 GBP;

https://www.ebay.co.uk/itm/TOYOTA-PRIUS ... 3462032264

And battery modules for 850 GBP (half that via group buy) per ~30 miles range;

viewtopic.php?f=11&t=30&start=10#p9825

[Kevin Sharpe]

On today's EV course we assembled a welded Prius Transaxle and hope to spin it up with a Toyota inverter tomorrow.

The Gen 3 transaxle and inverter were tested today

https://twitter.com/NewElectricIRL/stat ... 41280?s=20

[celeron55]

Don't take me wrong: I think a Leaf motor with stock inverter and stock 8:1 gearing is plenty for moving some 3500kg around between 0 and 100km/h. The same should apply to Prius too. Hill starts can be a problem if you're not smart about it, but on a gravel road you'll be close to losing traction anyway.

Be aware of regulators who may require lots of hill climbing ability. I think someone mentioned 18% @ 60km/h for TÜV? Does it apply to towing?

[Maker_of_Things]

That's a lot to think about.

The Leaf option sounds good, but I can appreciate there will be a cost to it.

The Prius option seems affordable in terms of buying the parts.

I have no idea which would lead to easier conversion work later on so will have to take your advice here once I decide.
My 'ideals' they are just my ideal wish list that I think are reasonable for a budget, but equally I know I may have compromises to consider. Range vs cruising speed vs load capacity vs towing. I will have to see which ways I can compromise those so I don't end up with a car that serves little purpose for me.
I could do towing with much limited range and speed. And all the range at reduced speed. I could lose the spare wheel well and carry the wheel in the load area (or roof rack for a limited distance).

My budget really is limited as the way I work is very much hand to mouth and skimming off any excess for projects as I go along. So to buy a motor, I deliver a job, get paid, buy some groceries and slip in a motor. Then do it again to get the inverter, etc. That's how I started with DC motors and controllers for a conversion but it took so long that AC became affordable, and cheaper really.
The batteries are more difficult as that is a huge lump sum in one go, maybe with an 'opportunity to buy' moment, so I'll smile lovingly at my elderly mother, with an IOU...

I will continue to research and ask questions.
Thank you all for your input so far.

[Maker_of_Things]

We'll need to do more work but it's not unusual to find dual motor Prius transaxles for 100 GBP;

https://www.ebay.co.uk/itm/TOYOTA-PRIUS ... 2857485964

Prius inverters for 100 GBP;

https://www.ebay.co.uk/itm/TOYOTA-PRIUS ... 3462032264

And battery modules for 850 GBP (half that via group buy) per ~30 miles range;

viewtopic.php?f=11&t=30&start=10#p9825

Those are on my watch list now.
Are there critical components that have to be with the gearbox, and the inverter? I don't want to foolishly buy one with a small part or connector missing that is irreplaceable or costly to buy.
Thank you.

[jap]

I got the impression that towing is a big part of your work, so I want to go through that with a bit more detail.

Apparently you are allowed to tow 1200kg with the smallest petrol engined variant of your car, so lets use that as the minimum benchmark. It has 148nm of peak torque at over 4000 rpm, and total reduction of about 14 with first gear. So well over 2000nm at wheels at most.

Your current TDi engine has peak torque of 250nm and total reduction of 12.8 at first gear, so well over 3000nm wheel torque at most. What makes your current motor great at towing, is that you have 150 to 200nm right after idle, so manouvering and going over curbs while towing etc. is easy.

Gen 2 Prius transaxle will produce whopping 400nm of torque with MG2, but it has only 4.113 reduction, so you have only 1600nm at the wheels. With welded planetary gears and a second brain to use MG1, you might get to 2000nm. That is if you can tune them as well as factory that has rated them for those numbers. You could also argue that you could get more torque using more amps, but until someone shows up with a dyno slip, that is only speculation.

You can likely tow with all of these setups, but I would much rather have performance closer to original TDi engine with a gearbox to use when needed. Leaf motor has just that with 250nm, but it will cost 1000gbp.

Comparing the cost of that 100gbp Prius transaxle, you would need a second brain to access enough torque, set of drive axles and custom mounts. So in reality that is looking more like a 500gbp option.

I would propose a Meiden motor from Mitsubishi Outlander for alternative, I think those were rated at 195nm and advertised under 500 at secondlife ev? You might find a better deal from a junkyard parting a Outlander PHEV. Adapter plate and a shaft coupler might be something you could make yourself? Bonus compared to a prius setup is that theres no need for tinkering with driveshafts and gearbox side mounts.

[Maker_of_Things]

Thank you, Jap.

I don't tow frequently, but sometimes it is the only way to deliver a project that won't quite fit in the back of the car. I feel a trailer beats having a massive van that spends most of its life empty in use. One of the deciding factors in buying the TDi Octavia was being able to push/pull the trailer at very low speed without slipping the clutch all the time to keep the engine speed up.
If it comes to it I can keep my other car, the Octavia Scout for towing if I have to but it sorta defeats the object of trying to get rid of the diesels in my life.

So if I went the Leaf/Mitsubishi motor options I can at least pull the trailer for work. I may end up compromising the initial range and looking into a bigger battery pack later on, if that isn't too complicated.

I'll have to see how to wrangle funds around that if that is what I have to do and look at the motor options.