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VW ID3 Batteries swapped into a Leaf on Aliexpress?

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6.3K views 6 replies 3 participants last post by  windraver  
#1 ·
Found a listing on Ali Express where they are saying its "possible" to swap VW ID3 modules into a Nissan Leaf Battery Pack. They're suggesting it'll get 55/54/40/30kwh (too many numbers in the listing)


Its kinda an interesting idea so I thought I'd share in case anyone is interested in another unique project like @Dala

Its not entirely clear what BMS they're using but my guess is that it would have to be the Leaf BMS in order to minimize the conflicts between the Leaf systems and the battery. If it was a 40/62kwh BMS then I'm guessing its a Bruteforce replacement. If the person is starting from 24kwh then they'd need to upgrade the BMS which means they'd need to also upgrade the current sensor (Based on my experience). Plus if its in a Leaf then they'd need Dala's CAN Bridge to make it work.

Assuming they're using the Leaf BMS, the next issue is the description:
This is a running project for Leaf battery upgrade. We use brand new VW id3 battery. Total 400 v, 55 kwh, 156 ah, 96S, 8 modules.

We will offer BMS(LBC) wire and show you how to restructure the case.
Some relevant numbers
  • Listing is for 8 ID3 modules
  • A single ID3 module contains 24 cells.
  • The 40kwh Leaf has 24 modules, 96 cells total
  • A single Leaf 40kwh module contains 4 cells
So total, we're looking at 192 available cells from the ID3. So I'm guessing they're going to run some cells in parallel to drop it down to 96 cells going to the BMS.

If we're running the 2 cells in parallel in the ID3 then that means each ID3 module = 3 Leaf Modules.

ID3 module has 6.85kWh
Leaf G4 Module has 1.6 kWh (x3 = ~5kwh)

A single ID3 module would thus provide excess capacity.

Only issue remaining then is that the BMS won't be able to fully charge the 55kwh to its fullest if its at the 40kwh setting... and I'm not sure how the 62 kwh BMS setting would handle it... could it? (I haven't worked with the 62kwh BMS).

Leaf module is 8.7kg; (x24 = 208.8kg)
ID3 Module is 32 kg; (x8 = 256kg)

So on that note its heavier and whether the full capacity is "accessible" or not could possibly determine if this is even worth swapping.

6.85kWh * 8 modules = 54.8 kWh total capacity

Assuming we can access the full capacity, thats
ID3 214.0625 Wh/kg
Leaf 191.57088 Wh/kg

So I guess the ID3 is more efficient if we can access the full capacity.

So from a back of napkin brainstorming... sounds feasible? It might also mean that these VW ID3 modules can be used in place of Leaf modules for anyone doing the Resolve EV conversion like myself and @Electric Land Cruiser or anyone else who is searching for modules for their conversion or upgrade.

Final thing to note is, these are the same sellers I bought my Leaf modules from. They were not shipped well as the packaging was thin and thus they came pretty beaten up. So far fortunately my pack is working well but just something to beware of. Hopefully 8 modules are easier to ship than 24 Leaf modules.

These are some pictures from their listing:

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PDF of listing in case they take it down:
 
#2 ·
It is a strange listing. More for the details that are missing than anything else. For the amount of money involved you would want more than a few pictures of what looks like the beginning stages of a project. There seemed to be a lot of BMS wiring but I would have expected the wiring to connect to the existing module cell voltage monitoring connector. But it looks like they are running wires to each cell junction? The ID3 modules seem to fit nicely and if the factory cell monitoring connectors could be used then it would be a neat solution. As you point out it would likely need Dala's CAN Bridge. It is a pity this post didn't set off a discussion as it would be interesting to know what other people thought, especially anyone that had actually purchased the item. The listing description is very brief and doesn't really give a clear idea of what is included and what else is required. Even a link to a youtube video or a downloadable copy of a set of instructions would be helpful. With the adhesive dispenser lying nearby in one of the photos I wonder if the modules are glued in?
 
#3 ·
I certainly wonder about how they'd deal with cooling. Saw someone's car caught fire recently and using alternative batteries requires folks to take into account how they were cooled in their source vehicle. (I don't know too much about the vw.id3 so I'm not sure how they handled cooling. The benefit, or flaw of using leaf modules is that they aren't cooled. They say air cooled but its really just an airtight box made of metal... maybe the box cools it a little bit. But given they are relatively stable across the world, they're really easy to work with.

BMS in the leaf is relatively "simple" really. Its just checking voltage between two points. If you start stacking it in parallel, it wouldn't know. As long as the total voltage and all the BMS points are in use, it'd theoretically work. If the car already has a 40kwH BMS installed, the Leaf itself actually wouldn't know it has a new battery since its a bruteforce replacement (term coined by Dala).

So from a perspective, it looks feasible. As for upgrades from 24kwh to 40kwh, I'm pretty certain you'd need a new BMS (since the BMS tracks the capacity) and any change to the BMS would require the can bridge.

My guess is these guys are selling to DIY and folks who can DIY this probably won't need a set of instructions.