I remember the evtv video where someone managed to use a chademo charger, but there hasn't been much news on that recently. Nowadays ther are more chademo and CCS charging today as well as the new 150kw charging within the next two years. Has there been anything new on dc charging for diy EV conversions?
Dc Charging for Conversions
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I was thinking about creating a new thread, but I think this one fits well enough. First I'll start with questions on the original post. Then I'll add a few of my own that are related.
My opinion is that all of the issues surround what I call "Goldilocks opportunity charging" and the equipment needed to support it. DC charging DIY is going to be a tough road due to the power involved. 150 Kw is delivering 375-500 amps to a nominal 400 volt battery. Even current 25 Kw (63 amps) or 50 Kw (125 amps) is going to take some significant management to do safely.
So my question is other than availability what does DC fast charging really buy that's worth the effort to manage?
Currently I'm looking at another approach. On board commercial EV chargers range from 3.3Kw to 10Kw with the exception of Tesla and its options up to 18-20Kw. They are perfectly sized to meet the goal of multi-hour or overnight charging. There are also the DC fast charging options starting generally at 24 Kw and up. But the hole that I see is the magic middle (Goldilocks) between the top of the onboard charger and the DC fast charger. For example J1772 AC can go up to 80A (19.2 Kw). It's even possible to get 9.6 Kw from a 14-50 50A campground socket. However, the onboard charger can't take advantage of it fully because it's above the maximum power of the onboard charger.
So my interest is a 20Kw charger that speaks DCFC protocols that's small enough to be hauled around. Recently I've been looking at the Chevy Bolt. So in particular I'm really interested in CCS-Combo that takes 50-80A AC in and delivers 9.6 - 19.2 Kw DC out.
The missing information for both CCS-Combo and CheDeMo are the high level communications protocols necessary to make it work. CheDeMo is simpler because it uses a CAN physical network while CCS-Combo uses the HomePlug Green PHY protocol that essentially talks TCP/IP over the J1772 pilot line. But I've hit a brick wall in my research in terms of any of the higher level protocols necessary to get a vehicle to accept a charge.
So it looks like we're looking at two sides of the same coin: the communcation necessary to get a DCFC station to talk to a DCFC vehicle.
Any suggestions of where to look for protocol details would be very welcome. Maybe there we can figure out how to get either or both CCS-Combo or CheDeMo to throttle down both voltage and current to something managable.
ga2500ev
My opinion is that all of the issues surround what I call "Goldilocks opportunity charging" and the equipment needed to support it. DC charging DIY is going to be a tough road due to the power involved. 150 Kw is delivering 375-500 amps to a nominal 400 volt battery. Even current 25 Kw (63 amps) or 50 Kw (125 amps) is going to take some significant management to do safely.
So my question is other than availability what does DC fast charging really buy that's worth the effort to manage?
Currently I'm looking at another approach. On board commercial EV chargers range from 3.3Kw to 10Kw with the exception of Tesla and its options up to 18-20Kw. They are perfectly sized to meet the goal of multi-hour or overnight charging. There are also the DC fast charging options starting generally at 24 Kw and up. But the hole that I see is the magic middle (Goldilocks) between the top of the onboard charger and the DC fast charger. For example J1772 AC can go up to 80A (19.2 Kw). It's even possible to get 9.6 Kw from a 14-50 50A campground socket. However, the onboard charger can't take advantage of it fully because it's above the maximum power of the onboard charger.
So my interest is a 20Kw charger that speaks DCFC protocols that's small enough to be hauled around. Recently I've been looking at the Chevy Bolt. So in particular I'm really interested in CCS-Combo that takes 50-80A AC in and delivers 9.6 - 19.2 Kw DC out.
The missing information for both CCS-Combo and CheDeMo are the high level communications protocols necessary to make it work. CheDeMo is simpler because it uses a CAN physical network while CCS-Combo uses the HomePlug Green PHY protocol that essentially talks TCP/IP over the J1772 pilot line. But I've hit a brick wall in my research in terms of any of the higher level protocols necessary to get a vehicle to accept a charge.
So it looks like we're looking at two sides of the same coin: the communcation necessary to get a DCFC station to talk to a DCFC vehicle.
Any suggestions of where to look for protocol details would be very welcome. Maybe there we can figure out how to get either or both CCS-Combo or CheDeMo to throttle down both voltage and current to something managable.
ga2500ev
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"EVTV" (Colin, Damien, and Jack) had a lot of success with CHAdeMO rapid charging and the project only stalled because some commercial chargers do not work reliably below 200V (the nominal voltage in Damiens car). Damien recorded a number of videos including this one;
Today we have lots of active development planned for CHAdeMO and CCS especially on cars that are using the Tesla 10kW chargers. Once we have cars on the road I think you'll see them rapid charging
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Practical how? There are only three or four contexts in which DCFC is essential:
1. Long range travel.
2. Extremely short term charging windows.
3. DCFC availability in places where L2 isn't.
4. DCFC is the primary charging option due to no L1/L2 at home/work.
There's a project floating around adding ChaDeMo DCFC charging to a Ford Focus Electric. Uses an Arduino with a couple of CAN buses as the onboard charge controller. Developer estimates total cost at about $2000 with assembly/programming required.
Tony Williams also has a ChaDeMo retrofit project for the Toyota Rav4. This is a $3k project.
So if you have a moment, can you give a use scenario that you believe justifies the expenditure or dollars and effort at that level?
ga2500ev
Most likely a road trip of several hundred miles where level 2 would too slow.
Though if I did add fast charging that would probably be for later, when it can be done for cheaper. Maybe use a port from a used ev.
Mainly for a conversion I've been thinking of perhaps one of the newer Mazda rx-8 cars, with a large battery pack, either dual chevy volt battery packs, or a battery pack from the coming NMC 811 packs in the next two years. For a drive unit, either a leaf motor, a bmw i3 motor, or the small tesla DU, along with a 10kw tesla charger. Other parts would also be from used OEM parts.
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That may be the cost of a commercial product for an OEM EV but has no relationship to the costs for a conversion. For example, I fully expect the controller board in my Tesla charger will support the CHAdeMO protocol (and eventually CCS). All I'll need is a CHAdeMO-to-Type2 adapter from Tesla (mine cost 300 GBP on ebay).
Hey Kevin, in the usa what would be needed for fast charging since I don't think type 2 is used in the us
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All you need is a couple of contactors, a DC connector, and a Arduino (iirc Damien used a DUE).
The most expensive part is the connector. To keep costs down you could use a CHAdeMO connector from a wrecked Leaf, or a Tesla Model S connector with an adaptor, or even a US CCS connector (the J1772 version).
Oh also would wonder how fast they would charge, at least 40kw or so, though there is a slowly approaching wave of 100kw+ chargers. However that would need an ev with a battery pack over 50kwh to fully exploit those networks, they also be limited to minimum 200 volts because of those voltage issues you've mentioned.
The thing I like about conversion using oem parts, is that you'll never run out of parts if replacement becomes neccesary and the battery pack could be replaced with a higher energy, but lighter and smaller pack. Like with the 2019 nissan leaf pack which won't be that much heavier than the current 40kwh and liquid cooled.
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Damien's conversion is supporting AC and CHAdeMO using the Tesla car connector and the Tesla adaptor. See car connector here.
Other European conversions I'm involved with are supporting AC, CCS, and CHAdeMO using the Tesla adaptor. See car connector here.
We've chosen this path because one connector on the car supports 1 and 3 phase AC, CHadeMO DC, and CCS DC
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That does seem to be the most versatile, being able to use most chargers. How much does the used tesla connector cost, I've found some adaptors on eBay for 300 usd, would the connector be a similar price? Oh as well how large of a pack do you think could be fit into an rx-8 without intruding on trunk space or rear space. i saw on evalbum an rx-8 with 71 200 kokam cells converted in europe, I think batteries now a day should be more energy dense.
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Yeah that would make, since you're never converted that particular car. Hmm I remember on your bus thread that you planned to test i think either a tesla or type 2 connector at over 50kw. I know that in europe, tesla uses a type 2 with longer pins and uses it at just over 120kw. Do you plan to charge at that kind of speed in a future conversion? Your 75kwh pack should be readily able to accept about 8.5kw per module.
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We've measured the pins on the Tesla Type 2 connector and they appear to be the same as any other Type 2 connector. The only difference is that Tesla use all four AC pins when DC charging.
At public locations the charge rate will be constrained by the charger and my reduction in pack voltage to 300V (I'm only using 12 modules now).
However, we intend to develop our own supercharger which will be used to push the system to it's limits
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