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Reduce Max. Current while DC Charging with CHAdeMO

Discussion in 'Prime Plug-in Charging' started by Plugin_RK, Nov 5, 2022.

  1. Plugin_RK

    Plugin_RK Junior Member

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    Our 2018 Toyota Prius PHEV is an Japanese import and has a CHAdeMO port for DC charging. We have used it once - it charged from 0% to 80% in 17 minutes providing 4.8kWh of power i.e. a rate of 17kW at a current of 74Amp. (I've described this elsewhere in PriusChat.)

    Since frequent fast charging is generally accepted as bad for the battery but we'd like to be able to charge quickly e.g. holidays, etc, my question is - can I somehow reduce the max current by 1/3 (for example) e.g. to 50 Amp? This would presumably significantly reduce the damage to the battery but only increase the charging time by a small amount e.g. 8 minutes at 50 Amp.

    The in-built current limiter in the PHEV only applies to AC charging i.e. to 8 Amp, but doesn't effect the DC charging rate. (Anyway, a DC limit of 8 Amp would be far too low for our purposes.)
     
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  2. drash

    drash Senior Member

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    I would take temperature and time of day into deciding whether to DC charge your car. If it is sunny where the sun load would cause the car to heat up and/or a temperature of higher than 70 I might refrain from DC charging. And of course I'd take into account whether I just used the car prior to recharging it. If the car has been at rest for at least 4 hours during a cool and/or shaded day then go ahead and recharge.
     
  3. Elektroingenieur

    Elektroingenieur Senior Member

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    I didn’t see anything in the Owner’s Manual (PDF, in Japanese) describing how to do this; as you noted, the charging current setting applies to 200 V AC charging only.

    In principle, one could design a device, to be connected between the vehicle and the charging station, that would rewrite the CAN communications (PDF; see page 6) from the charging station to the vehicle, to change the output current limit announced by the charging station to a lower value, causing the car to moderate its current demand accordingly. See JIS D 61851-24:2014, Annex A (page in Japanese) for the protocol details.
     
  4. Plugin_RK

    Plugin_RK Junior Member

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    Thank you for these insights into the complexities Toyota considers when limiting the DC charging current, drash. Our typical, intended scenario for CHAdeMO charging would be daytime at about 25degC (75degF) after driving for an hour or so in HV mode and a battery depleted for maybe 15 to 20 minutes before re-charging. We would like to almost immediately charge while having a short break then continuing on the journey - so driving both beforehand and afterwards. This would seem to me to be the intended scenario for CHAdeMo charging. If there is time to charge from a 230V AC supply then I'd choose this as it's healthier for the battery and probably cheaper (or free) where I'm likely to be.

    I am hoping that there is a hidden setting where the car can be told to never charge above a certain current e.g. 50 Amp, or less if Toyota's algorithm recommends an even slower rate. Such a setting might, of course, only be accessible using an OBD2 connection.
     
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  5. Plugin_RK

    Plugin_RK Junior Member

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    The design and build of this device would be beyond me, unfortunately. As mentioned above, I am hoping there is a menu position where I could override the car's automatic current control settings to limit to a max. of about 50 Amp (perhaps only accessible using an OBD2 connection). As noted by drash above, there are many factors to consider - hopefully Toyota's charging regime already adjusts the charging current accordingly, so I' like to be able to limit it's set current to a lower maximum.

    With the probable future increase in demand for fast charging as EV use expands it would seem very useful to be able to fast charge with minimal, if any, damage to the battery. As I've described elsewhere, our single trial using CHAdeMO charged from 0% to 80% in 17 minutes. This time was too short to enjoy a relaxed drink, a bite to eat, and a visit to the rest rooms - so after the fast DC charge the car sat around doing nothing for about another 20 minutes. This extra time could have been used to reduce the DC charging current.

    Although unlikely to be possible with our current PHEVs, best of all would be if we could set the DC charging regime to be finished after a certain period (set depending how long we're away) and let the car decrease the DC charging rate to the minimum current to charge in that time. That would minimise battery damage (and spread also the loading on the power grid).
     
    #5 Plugin_RK, Nov 6, 2022
    Last edited: Nov 6, 2022
  6. drash

    drash Senior Member

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    Got it, so don't be afraid to liberally use the air conditioner. I would also recommend that if you haven't, make sure you enable the Traction Battery Cooler check screen in the Meter Settings on the MID. Select yes when the Traction Battery Cooler requestor pops up when you turn the car off. That is also an indicator that the battery is quite warm. If it is warm then the selection will default to Yes and you can just press the select button on the steering wheel (page 128 Owners Manual). I wanted this to be a default setting via the the Vehicle Settings, but apparently the only thing selectable in that is the Traction Battery Heater.
     
  7. vvillovv

    vvillovv Senior Member

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    according to DrPrius the battery cooler message shows up when battery bank temps reach 38 C / 100 F.
    That is only my experience, YMV .
     
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  8. black_jmyntrn

    black_jmyntrn Senior Member

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    ohhhh really!! let me read through this... where are you located? please can i hang out with your car for a few hours? lunch, carwash and tank of gas on me just to tinker a bit! I'm on a mission to add this to my prius and right now yours is the key for me to reverse-engineering all of this!! I'm in Cali and happy to drive to Maine if that is where you are, that to relay my need and as the year ends urgency to complete this project...

    have you tried to charge on a fast charger? they are not like the l2's out there and from what Im finding out fewer far in between. I'd like to think on one of those, you can charge to full in less than 30 minutes, right? [just read more.. SEVENTEEN MINUTES!! OHHH LAWD!!! MUSIC TO MY EARS!

    that and now i need to look this up, if the gen 1 came with CHAdeMO or not. I have a plugin and the ecu from japan spec plugin... also have a prime and with you the ecu from japan spec. Id want to download the files off your ecu to then compare them to our prime. than use from that to compare the two of the gen 1 to see the differences between them all. my goal of a 50kWh battery charging in less than 30 minutes or less than an hour have just taken a huge leap forward thanks to you and your purchase. happy to help you in your goals at the same time. imagine, awd prime prius, with a motor more powerful than the rav4 prime.... baby tesla killer right?
     
    #8 black_jmyntrn, Nov 9, 2022
    Last edited: Nov 9, 2022
  9. Elektroingenieur

    Elektroingenieur Senior Member

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    Since @Plugin_RK has a right-hand drive Prius PHV car built to Japanese specifications and access to CHAdeMO charging stations, I’d assume his “Pacific Coastal city” is on the opposite side of the Pacific from ours in California.
     
  10. black_jmyntrn

    black_jmyntrn Senior Member

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    noooooooo I wasnt sure if it was here, didnt know was right hand either! but here in the states, im sifting through the Nissan LEAF and the Mitsubishi Outlander PHEV as they have CHAdeMO and could use inverters and such on the Prius but still... attention shifting to non US prius and the parts used for CHAdeMO charging...
     
  11. Plugin_RK

    Plugin_RK Junior Member

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    Hi black_jmyntrn, I'm delighted at your enthusiasm, however, if you did happen to head to Maine you'd be driving in the opposite direction. I'd also suggest a boat or plane as it's a long way ...
    Yeap, Elektroingenieur hit the nail on the head - ours is a [2018, Gen 2] right-hand drive Prius PHV car built to Japanese specifications. And there's water between us (... lots of it).
    But don't let the distance and waves get in the way of what might be a very interesting bit of fun with really useful purpose. It is amusing that you'd like to speed up charging (a lot) while I'm looking to slow it down (a little). I'm happy to try moving things along.

    We have an 8.8kWh battery (giving ca.40km/25mile range) while your Gen 1 Prius has about half this i.e. 4.4kWh (giving ca. 20km/12mile range) according to https://en.wikipedia.org/wiki/Toyota_Prius_Plug-in_Hybrid#Battery_and_range_2. Installing a 50kWh battery is an interesting goal, however, since a battery of this size weighs much more i.e. about 11 times a 4.4kWh battery, then you'd have problems with weight and therefore chassis strength and braking capacity. Also space would be an issue. Presumably you will have to remove the ICE/petrol/gas engine to be able to make your conversion work, so you'd be changing a hybrid into a full battery-electric vehicle. You'd probably be wise to check whether your final design could be certified as road-worthy and insurable by the relevant authorities, etc. before dismantling and modifying. (It might even be cheaper to buy a used BEV and modify that.)

    So what's the next step? Presumably I need to buy a OBD2 connector and install an app onto a mobile phone or to connect to a laptop? I'd need advice regarding which combination connector/software is best. Can you/anybody help with this? Hopefully the Prius PHV/Prime owners have recommendations?
     
  12. Plugin_RK

    Plugin_RK Junior Member

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    Thanks for the tips. The Traction Battery Heater was already ON (and I've left it so). Since it can get a bit cold here in winter it is useful.

    There isn't a Traction Battery Cooler setting at all. I assume that means the equipment is not present in this version of the car and so wouldn't be accessible even with OBD2 etc. The air temperature here seldom rises to 30degC (90degF) or above so a Traction Battery Cooler might just be less important than in US e.g. California.
     
    #12 Plugin_RK, Nov 11, 2022
    Last edited: Nov 11, 2022
  13. vvillovv

    vvillovv Senior Member

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    the pack cooler option is buried in the settings options on the (MID 4" screen, to the left of the speedometer (in your jp car ) ). It's not easy to find even after having changes it a couple of times. Just in case it might be there hiding from you.
    If you're gonna be using DC fastl, I'd recommend monitoring your pack. Not only pack temps but also internal resistance and voltage difference between cells. *(see Dr Prius app and techstream lite).
    Also, take a look at charge mode ! It might give clues to how DC fast could effect your pack.
     
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  14. black_jmyntrn

    black_jmyntrn Senior Member

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    hehehehe... I'm a lot further along with this than my initial words let on. now I need the part numbers of the parts on your car from the plug in connector on the outside all the way into whatever part number starts to be the same on mine on flowing through the rest of my car. out here we have parts.toyota.com i enter my vin and can pull the part numbers and diagrams. Do you know the site to pull for yours? With all of the numbers and scematics i can begin to source all of them.

    the rav4 ev has close to 50kwh, larger battery and older tech yes, but the new batteries and companies making them give me hope as the new 18.1kwh from the nx450h+ can work in the prius and they say, lighter and better than the 18.1kWh in the rav4 prime which will not work in our cars.

    i have multiple obd2 and i have the devices needed to read/write the ecu... since I have japan spec gen 1 phev and my us spec gen 1 phev, i just need a copy of your ecu from the gen 2 phev japan spec to use in the reverse engineering of the gen 2 phev i have.
    https://black.jmyntrn.com/2021/01/02/new-obd2-bluetooth-adapter-is-better-than-carista/

    this is why you dont get a cheap obd2 dongle...
    https://black.jmyntrn.com/2022/05/03/do-not-buy-a-low-cost-obd2-dongle-for-your-prius/

    so next steps, figure a way to get a copy of your ecu file and get parts from yours on order asap...

    not sure your goal, but.. this is the adpater to get and I use hybrid assistant as it allows me to log the data. I have a data visualizer i plan to load the data into so that combined with notes on dates for oil change, new tires, rotate tires... i can go back to see what made a difference.
     
  15. Plugin_RK

    Plugin_RK Junior Member

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    I searched again through all the MID settings and couldn't find a setting for the Traction Battery Cooler, which I expected to be in the same menu as the Traction Battery Heater. It wasn't there so I also looked elsewhere without success. I have read somewhere that a Traction Battery Cooler is not fitted in all models of the Prius PHV. (I have a vague memory that it might be the perhaps the English models, but I could be wrong here.)
    I'm hoping to get advice regarding which OBD2 connectors and apps/programs are best. Then I will indeed monitor everything I can. Hopefully I can also find a way to limit the max. DC current at about 50Amp instead of current 74Amp - this is my immediate goal to open the way to using fast charging more often.
     
  16. Elektroingenieur

    Elektroingenieur Senior Member

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    Third-party websites that unofficially post Toyota’s Electronic Parts Catalog data and images often include the catalogs for Japanese models. Search for model codes ZVW52-AHXEB, ZVW52-AHXGB, and ZVW52-AHXHB (without the “A” or “W” suffixes indicating models for North America or Europe), catalog code 224130.

    See also this thread; I still recommend the ZVW52 Electronic Technical Manual (電子技術マニュアル).
     
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  17. Plugin_RK

    Plugin_RK Junior Member

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    Hi Elektroingenieur, thank you for your earlier post. Unfortunately I can't read Japanese, so I can't read the handbook which came with our car nor the online PDF you refer to. I would certainly like a handbook for our car which I can read but haven't been able to find one for our 2018 Prius PHV import from Japan. (Most online handbooks are for US or English version of the Prius.)
    You post elsewhere regarding CHAdeMO charging was interesting especially as it applies to the Japanese version (which we have). So I have a few questions:
    1. An online translator converted that short comment in Japanese by Toyota as "There is no problem if you use the quick charge about once or twice a day. However, we recommend that you refrain from excessive rapid charging as it may affect the capacity of the drive battery." Do you know if "rapid charging" refers to DC CHAdeMO charging at ca. 70Amp-75Amp or faster AC charging at 16Amp (maybe 32Amp)? (I wonder what "excessive" means if a daily fast charge is possibly acceptable.)
    2. Was that comment relevant to a Japanese 2018 Gen 2 Prius PHV or something possibly rather different e.g. the Gen 1 version?
    3. This comment by Toyota suggests that I shouldn't worry too much about DC fast charging maybe 10 to 20 times a year mainly while on summer holidays.
    4. Do happen to know where I can a find a handbook in English for our Japanese import version of the Prius (German would also be OK too)? Or a translation of the PDF your link to a Japanese Owner's Manual refers to?
     
    #17 Plugin_RK, Nov 12, 2022
    Last edited: Nov 12, 2022
  18. Elektroingenieur

    Elektroingenieur Senior Member

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    Yes, I was discussing the ZVW52 series, produced from October 2016.
    I’m inclined to agree—but consider that Toyota’s customers in Japan, for whom that FAQ answer was written, might have different expectations than yours about the useful life of the vehicle and its HV battery.
    I’m not aware of a global source for translated owner or service manuals for Toyota vehicles built for sale in Japan, which are generally prepared only in Japanese. In some overseas markets, Toyota distributors offer translated manuals to their local used-car customers—for example, see the answer to “How do I get an owner's manual or technical information for my used import?” on Toyota New Zealand’s FAQ page—but I don’t know specifically about manuals for Prius PHV cars.

    As you’ve found, the manuals published by Toyota in English and German are for Prius Prime cars sold in the U.S. and Prius Plug-in cars sold in Europe. The manuals available from Toyota UK cover a right-hand drive version of the car but not features such as DC fast charging.
     
  19. Plugin_RK

    Plugin_RK Junior Member

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    Thank you. Could it be that "rapid charging" refers to DC CHAdeMO charging at ca. 70Amp-75Amp rather than just faster AC charging at 16Amp (maybe 32Amp)? (It's probably CHAdeMO charging but I'm just being cautious here.)

    In light of the above I would still like to reach my original goal of reducing fast CHAdeMO charging from over DC 70Amp to a max. of DC 50Amp - especially when my driving breaks on trips are longer than just 17minutes anyway and more like about half an hour, so there's absolutely no need to push the upper limits of rate of charging.
     
    #19 Plugin_RK, Nov 12, 2022
    Last edited: Nov 12, 2022
  20. Plugin_RK

    Plugin_RK Junior Member

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    While researching the OBD2 connector which you indicated I found the following comment: "MX+ supports all legislated OBD-II protocols, plus advanced Ford & GM vehicle networks (MS-CAN and SW-CAN). MX+ works with all 1996 & newer cars and light trucks sold in the United States, and also supports EOBD, JOBD, and all other international variants of OBD-II. If you don’t require access to advanced Ford & GM networks, consider purchasing OBDLink LX Bluetooth." Do you have any thoughts regarding this comment e.g. use instead of the OBDLink LX Bluetooth if there are any advantages?