[WIP] Leaf to VW Type 2 Campervan

[marcexec]

Sorry I meant to get it road legal/taxed/insured etc. so you get some (even minimal) use out of it. Midweek shopping or recycling centre.
Go to meetups, even to troll

[ianlighting]

Despite well informed guidance to stick to 1 battery box, I am sticking to my plan B of 2 boxes.

This led me to wondering about fuse positions. I know usual advice is a fuse in each box, which I will be doing. Most guidance I have read suggests fuse position at the start. But Nissan’s Leaf has their OEM position in the central half way point, just before the service disconnect.

I have been intending to stick to as close to OEM as possible, although 2 boxes clearly substantially breaks this approach.

If I put a fuse at the start of box #2, this is in effect immediately after the disconnect situated in box #1. Since I am modifying Nissans design by having 2 boxes, should I also move the first fuse from adjacent to the disconnect and instead position it early in the chain, at the start of box #? I can easily accommodate this. I just have 2 conflicting approaches to reconcile, Nissan’s vs ‘good practice’.

[tom91]

I have been intending to stick to as close to OEM as possible, although 2 boxes clearly substantially breaks this approach.

It is strongly recommended you be very very careful when altering anything with an OEM bms. Things like wire lengths can have very very strange effects on behaviors. Moving a fuse/disconnect can have some catastrophic consequences if you ever connect the BMS up, have the disconnect out and then draw ANY hv power. It results in a black spot on you BMS.

This is due to BMS architecture. It CAN ONLY be split where the OEM disconnect is.

[ianlighting]

Appreciate your advice @tom91.

I’ve reread my post and your response. I appreciate you can only give general guidance, but that it is to not move the fuse / disconnect.

In my scenario, I am looking to add a fuse to a second box, which seems to be good practice. I am unsure if you are saying this introduces its own risk that I should avoid because the OEM BMS is not designed around that 2nd fuse? Is it fine in principle, or am in uncharted territory once I break an OEM design in this way with a 2nd fuse, so at my own risk?

Yes, I asked about moving the current middle OEM fuse, but it’s no problem to leave as is, next to the disconnect.

For what’s it’s worth, subject to detailed measuring, I’m expecting to add 1m or less BMS wire to achieve the 2nd box.

Thanks

[tom91]

so at my own risk?

As always you do everything at your own risk. Yes always fuse batteries in enclosures. If the fuse in the second pack blows it will take the BMS with it, however this is okay as the alternative is way worse.

[Bratitude]

in reference to what tom said, the leaf bms has a split in it at one point, which is also where the fused disconnect sits.

i think around cell 48 (makes sense as thats smack in the middle of 96)

you have to understand that the bms connection can act as a current path, so even though you put a HV fuse some where...and it blows...current can still run through your bms. this misunderstanding in the conversion space + pared with overlooking bms systems (slapping in a Orion for example) leads to fires.

so your going to need to add some sort of fusing to each cell tap to the modules that are in a different box from the bms.

in any case you can only split a leaf pack into 2 equal sized boxes when using the leaf bms.


then there is the issue of the cell tap voltage float. its not certain that the leaf bms will get an accurate cell voltage measurement the moment you lengthen/ add connectors to the leaf bms leads. so some testing will be needed to verify the bms is getting a accurate measurement.

battery systems are the hardest part in a conversion! hence why we recommend going with one box for now!

but with the 2 boxes it might be a better idea to go to a master/slave system like a dilithuim bms. each battery box has its own bms, and they link over SPI(?)

[ianlighting]

Plenty of food for thought there.

There was someone a page or so earlier saying he was following me because he thought it all looked so easy. I’m glad I tried to dissuade him from that idea as I knew I didn’t yet know very much about this game! Here’s the proof.

I hear what you’re saying Brat, about master / slave BMS to protect the system, and the humans. So I have a decision to make.

The master / slave BMS is not something I can do with the system I am using. It’s an OEM Leaf based system only. Can’t mix n match different subsystems or manufacturers. So it’s either stop where I’m at now and reinvest in an alternative solution, or keep moving forward to reach a conclusion on the current path, and then re-assess at the end to improve the deficiencies in the design. Possibly I can incorporate other mistakes I find along the way into a v2.

I don’t expect anyone's blessing for a suboptimal design if I keep on with the way I’m going. I’ll have a think. What’s in my head right now (subject to change), is reach the finish line, get it past DVLA, then see how best to refactor the system.

[johu]

Advertising block for Flying ADC BMS here
https://openinverter.org/wiki/16-cell_BMS

It should be possible to program it to look like the Leaf BMS

[Jacobsmess]

Advertising block for Flying ADC BMS here

Ah not another spambot

I was also going to suggest this alternative.

[ianlighting]

I have duly read the advertisement

If my objective would be to reduce risk, I think going this route would be counterproductive. That’s a reflection of my skills, not the product. I don’t think I have the engineering depth of knowledge required to make the Flying ADC BMS work for my needs. I would need too much hand holding.

Perhaps as a longer term parallel project I could learn. I will have a surplus 30kWh Leaf battery at the end of this, so there’s a candidate to play with. Maybe I can use that as a test bed since any fatal (to hardware not humans) mistakes will be less critical.

Of course, I would also need to buy another Leaf / Leaf motor, plus another target vehicle. I can’t tell you how excited my wife is going to be with this plan!

EDIT - hmmm… I suppose I do have that old rusty tractor…

[ianlighting]

Moving a fuse/disconnect can have some catastrophic consequences if you ever connect the BMS up, have the disconnect out and then draw ANY hv power. It results in a black spot on you BMS.

I was thinking about what you wrote Tom. If the service disconnect is out, this means the HVIL circuit is broken, so the contractors are open and no HV is able to leave. So trying to draw power, from the motor for example, isn’t going to do anything.

Also, since the BMS gets its power from the point immediately after the service disconnect, even if it is apparently wired into circuit, it is not able to control anything since it has no power itself when the disconnect is out.

What did I miss?

I’m talking about the Leaf system here, so that may be different to other systems of course.

[tom91]

so the contractors are open and no HV is able to leave. So trying to draw power, from the motor for example, isn’t going to do anything.

Correct any normal use case should be okay, any accidents when assembling can cause issues. Best practice to leave the BMS unplugged until the whole pack is assembled.

Does the Resolve controller utilize HVIL?

Do you have any diagrams for your wiring?

[ianlighting]

Does the Resolve controller utilize HVIL?

Do you have any diagrams for your wiring?

Well… actually you’ve got me thinking now. There’s no direct HVIL circuit into the Resolve controller itself. But I know you don’t get very far into the startup with the service disconnect removed. The exact response I can’t be 100% sure of without repeating the test. You definitely can’t go into drive.

But is this because of the HVIl circuit being broken at the disconnect, or because the HV doesn’t reach the 2nd contractor? Not sure.

As far as I recall the HVIL in the Leaf stays within the battery. When I looked at the main HV power cable connection to the battery, the HVIL loops through the connection to make sure the power cable is plugged in, but it doesn’t travel up to the PDM charger from what I could see. I don’t have experience with other makes to know if that’s normal, or just the way Nissan does it.

So, if the main power cable is not connected, this breaks the HVIL. But since this also stops the HV reaching the BMS I don’t actually know which thing is stopping Resolve-EV controller from starting up.

Perhaps HVIL is a red herring here.

Unless it’s just another safety input into the Leaf BMS, in which case, yes, Resolve-EV is indirectly dependant on this because if the BMS goes into error as a result of HVIL breaking, I doubt Resolve controller would start.

Sorry a bit rambly, working it out as I go there!

Diagrams are as provided with the controller. It’s not at the level of internal battery, because in theory it’s kept as OEM.

3rd button here gets you to their docs and the top doc is the wiring…
https://resolve-ev.com/products/resolve ... ault+Title

[tom91]

Not sure what level of checks are done by the Resolve Controller.

Also have not looked into the Leaf BMS CAN structure to see how many "safety" checks are reported. Currently none are implemented in Zombie.

[ianlighting]

Not sure what level of checks are done by the Resolve Controller.

Also have not looked into the Leaf BMS CAN structure to see how many "safety" checks are reported. Currently none are implemented in Zombie.

Thought a bit more. I believe in a Leaf the HVIL runs through all 3 connectors on the front of the battery, including the HVAC. I don’t use that currently. So if the Leaf BMS is complaining about it, either that message isn’t getting to the Resolve controller, or it’s being ignored.

So, on that basis, you may have to ignore all my comments about HVIL being relevant here! But appreciate your thoughts.

I’ll reread what was said here in the morning to see if I made any sense. Tired eyes now.

[johu]

The HVIL signal is reported by the LBC in a CAN frame. If you look at the stm32-car code I think I called it din_bmslock.
Not sure if the inverter checks for that itself or if the vcu needs to do it

Edit: 0x1db, byte 3, bit 3

[Cera]

Just popping to say hi

I'm struggling a lil with engine mounting due to my limited (nonexistent) welding skills but my build is still coming along slow and steady. Happy to hear my posts in DIYelcar had inspired you too, hehe

Best of luck with your great work!

- Sara

[ianlighting]

Just popping to say hi

I'm struggling a lil with engine mounting due to my limited (nonexistent) welding skills but my build is still coming along slow and steady. Happy to hear my posts in DIYelcar had inspired you too, hehe

Best of luck with your great work!

- Sara

Nice to hear from you! It’s been quiet on your build page, but I hope you’re making progress. I was impressed by your repair and restoration work so far. If you want a competition, I bet my non-existent welding skills are worse than your non-existent welding skills But then I’m not aiming to do anything super critical with my welding like holding up a motor under the chassis. When do we get to see another update over on DIY?

Edit - hmmm, maybe I’m getting confused, but you’re also posting on this site aswell as DIY! In my head you were on the other site, so I’ll have to have a read of your posts here in case there’s some detail that’s useful. I need to start thinking properly about brake vacuum soon, so maybe you’ve done the hard thinking for me already.

Do you post the same updates to both sites?

[Cera]

Nice to hear from you! It’s been quiet on your build page, but I hope you’re making progress. I was impressed by your repair and restoration work so far. If you want a competition, I bet my non-existent welding skills are worse than your non-existent welding skills But then I’m not aiming to do anything super critical with my welding like holding up a motor under the chassis. When do we get to see another update over on DIY?

Edit - hmmm, maybe I’m getting confused, but you’re also posting on this site aswell as DIY! In my head you were on the other site, so I’ll have to have a read of your posts here in case there’s some detail that’s useful. I need to start thinking properly about brake vacuum soon, so maybe you’ve done the hard thinking for me already.

Do you post the same updates to both sites?

I hope to update both here and DIYelcar "soon" but it feels like I'm just doing minor things and procrastinating the engine mounting so it's not felt like there's much to write about. But maybe multiple minor things could make a post too.

I did start in DIYelcar originally, then moved here somewhat. I'm notoriously bad at updating forum threads but since I had practically no knowledge, no experience and no skills I started looking for info in multiple sites. I also have a thread in Samba for mostly non-EV parts of the build. (https://www.thesamba.com/vw/forum/viewt ... p?t=715039) sometimes it helps to get input from multiple sources.

I've installed Tesla iBooster in the place of the original vacuum booster. See viewtopic.php?p=69524#p69524

Currently wiring 12V electrics anew and made me a new gear shifter modeled the original high beam switch knob, 3D-printed an copy with VW logo on it, got a 4-pos rotary switch (P-R-N-D) and drilled an extra hole to the dash:

[ianlighting]

Currently wiring 12V electrics anew and made me a new gear shifter modeled the original high beam switch knob, 3D-printed an copy with VW logo on it, got a 4-pos rotary switch (P-R-N-D) and drilled an extra hole to the dash:

Very good. If this is an example of your small jobs that you haven’t bothered to post, I would suggest you are over due an update! I bet there’s plenty of interesting good stuff you’ve been up to. Well, it’s interesting to other VW T2 converters at least

Thanks for the link to your post about brakes.

[T1Terry]

Back to the two batteries and a fuse between them, also add a 5 amp fuse on each BMS wire so it doesn't attempt to use the BMS as a current path on wires and circuitry that was designed for a much smaller current flow. The fuse will save the BMS if the mid pack fuse lets go, you are going to have to get into that part of the battery pack anyway, so just as easy to replace a hand full of 5 amp blade fuses while you are there ....

T1 Terry

[ianlighting]

Back to the two batteries and a fuse between them, also add a 5 amp fuse on each BMS wire so it doesn't attempt to use the BMS as a current path on wires and circuitry that was designed for a much smaller current flow. The fuse will save the BMS if the mid pack fuse lets go, you are going to have to get into that part of the battery pack anyway, so just as easy to replace a hand full of 5 amp blade fuses while you are there ....

T1 Terry

Yes, thanks. Matches what Bratitude and Tom were telling me a while ago. I admit I wasnt really thinking about the potential for large current down the BMS wiring when I started this, but its finally sunk in to my sluggish grey cells Appreciate the input.

I'm currently back to start the mounting of the motor before I start adding a load of weight into the battery boxes, but will circle back to batteries soon and look at where umpteen fuses can live...

Then brake vacuum, foot pedal, coolant pump mounting and circulation, VCU position...etc!

[T1Terry]

I can't remember if you were planning to use multiple modules in parallel and then connect them in series to build the voltage.
If you have access to the negative terminals on each module or the busbar on each paralleled group of modules, a copper tab you can bolt on soldered to one of these https://www.ebay.com.au/itm/22618998465 ... R4SRj7WtZQ and the BMS wire soldered to the other tab. Apply some Alminox compound to the blades of the spade terminals and it will mostly eliminate any resistance building up and causing bad voltage readings.

If you can't get easy access to the negative of the module(s) then a solder terminal and wire from there to a fusebox with multiple fuses. You can use this sort of cabling https://www.ebay.com.au/itm/22249723686 ... R7Cw5bWtZQ 13 conductor cable, light gauge and easy to thread through where ever you need. If you need multiple lots of 13 conductor cable, you can either add a different colour heat shrink at intervals along the cable to identify which module group it belongs to, or a quick and dirty one is a coat of spray paint a different colour ..... that one just risks the paint scratching off and looking untidy or losing its identification just is the position you need it

This cabling is great for driving relays as well, only problem is, if you use it exclusively, it makes it hard to identify cable runs .....

T1 Terry

[ianlighting]

I can't remember if you were planning to use multiple modules…

I’m using the stock 60kW Leaf battery. Did a break down here. viewtopic.php?t=5847

…although doesn’t really cover the cell taps in detail. Each module is a self contained lump. I’m not taking them apart to get to the cells, just using as is. Each module has its BMS plug with the correct number wires for that modules. So 4 for short, 7 for medium, 9 for tall. I’ll be breaking into these to add fuses.

[ianlighting]

Guess who is an idiot?

Hint: It’s not multiple choice.

I had Brat Industries make a Leaf to VW transmission coupler. I provided the clutch centre from my disaster bus and did my tests with that. All was great, as far as those tests went.

I’m now at the stage of putting the Leaf motor into my proper T2 that will be on the roads. And wouldn’t you know it, the number of teeth /splines on my bus are different. It has 24 instead of the disaster bus’s 20. This is kinda a major obstacle to progress.

Evaluating options…

1 - switch the transmission from my disaster bus into my proper bus? Don’t really want to. The disaster bus is a disaster (obvs). I don’t know it’s history but I can see its current state. I’ve only driven it a few meters and 15mph on a driveway. The transmission could be crap.
Compared to my proper bus, with relatively low miles.

2 - get another one made. Money, time… it was going to be a stretch but thought I was very possible to get it on road late spring. That plan has taken a kick to the danglies

Highly unlikely, but on the off chance someone has an unwanted Leaf to 24 spline VW coupler, I’m your target market

Final question - any guidance on getting a very snug fitting coupler OFF a Leaf motor? Presumably a load of heat runs the risk of damaging the motor. But there’s not a lot of leverage to whack it back off again.

It was all going so well…



EDIT : actually I may talking bollocks. It may all be fine. Possible confusion in my cold brain. Will confirm later.

EDIT EDIT : I hearby confirm the post above was bollocks.
What happened? Wouldnt go on, wouldn’t go on, wouldn’t go on… I start doubting myself. Start wondering if the 2 buses are different. No space to view the motor in the engine bay, so referred back to my photos I took of the delivered coupler. Counted the teeth. It confirmed my fears… Bugger it’s only 20, my bus has 24. Oh no(stronger language was used).
But guess what, I was counting the wrong end - the Leaf end! Idiot.

Motor is now roughly mounted.

I could just delete this post, but better left as a reminder to engage brain before panicking.