120v to 240v EVSE Modification

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by Redpoint5, Feb 8, 2015.

  1. Redpoint5

    Redpoint5 Senior Member

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    I purchased a used Leaf EVSE for $200 and have been L1 charging with it ever since. A couple things I don't like about L1 charging is the charge efficiency, which I've measured at about 70%, and the length of time it takes to charge when multiple trips are made close together.

    This Instructables article talks about how to modify a Leaf EVSE to use a 240v outlet and output L2 power. Since I already have a 240v line in my house and the few items I need to make the modification, I'll likely tackle this project.

    I now have the original Prius charger, and I'm wondering where the info is to modify the Prius EVSE to allow for L2 charging? Searching the web and this forum so far has not turned up any results.

    I see many posts endorsing sending the unit in to Phil's company for the upgrade, but that rubs me wrong in 3 ways. The first is that I bought the EVSE for $200, and spending $260 on a simple upgrade that involves very few parts seems silly. Next, I prefer to be a tinkerer than a consumer. Learning and doing is both more fun, and cheaper. Finally, I don't like Phil's attitude on the other forum I won't mention. He's not interested in educating people; only selling his product. I get that, and I can't blame him for promoting his business; I might do the same in his shoes. However, I participate in forums to both be educated and to educate others. If I can learn something and then pass along the knowledge, I will. Open source FTW!

    If someone can point me in the right direction for completing this mod for the Prius EVSE, I'll do a good write-up with pictures and possibly put together a Youtube video.

    A small bunch of wealthy hippies isn't going to put any meaningful dent in our fossil fuel usage. Eliminating the price penalty for going electric is the only way for the masses to convert.
     
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  2. IMkenNY

    IMkenNY Im just being nosy

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    I picked up a failed Prius plugin level 1 EVSE that had been upgraded to level2 by the popular $260 service.
    I decided against repairing the failed control board due to cost and questionable reliability.
    Instead I fitted an open-evse control board that is designed for the dual voltage level1 and level2 operation in the original Prius plugin EVSE housing for under $100 and it is working out very well.
    Here is a link to the open-evse project: open-evse - Open Electric Vehicle Supply Equipment (EVSE) - Google Project Hosting
     
    #2 IMkenNY, Feb 8, 2015
    Last edited: Feb 8, 2015
  3. Redpoint5

    Redpoint5 Senior Member

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    I like that and was considering going that route, but I have 2 EVSE units and everything I need to convert at least one of them. I'm more of a risk taker than a play it safe personality.

    The 240v shouldn't be much more strain on the EVSE unit since it's still limited to the same amperage. Charging the Prius should be easy for the Leaf unit, since it won't even approach the maximum current rating.

    Any idea what caused the failure on the unit you picked up?
     
  4. CaliforniaBear

    CaliforniaBear Clearwater Blue Metallic

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    70% doesn't seem to be correct. Example:
    Start SOC 22.7%
    End SOC 84.7%
    Charge 62%
    Nominal battery capacity 4.4 kWh
    Charge energy .62*4.4 = 2.728 kWh
    KillAwatt measured 3.05 kWh
    Charging loss 0.332 kWh
    Charging loss % 0.332/3.05 > 10.9%
    Efficiency 89.1%
     
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  5. bisco

    bisco cookie crumbler

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    i have never seen anyone do their own upgrade here. in fact, we seem to have very few, if any, tinkerers. you might have to be the missionary. all the best!(y)
     
  6. mmmodem

    mmmodem Taste Tester

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    $22.70 for material? I'd do this conversion if I had a different plug in vehicle. A 1 hour time saving over a PiP and added efficiency isn't worth the trouble for me. Good luck on your conversion. I'll be very interested in the results.
     
  7. IMkenNY

    IMkenNY Im just being nosy

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    A low voltage transformer failed, I was disappointed to see a thermal fuse bypassed.
    The cords and the relays carry the same current, so there is no problem with them. The big problem is with the power supply that was not designed for 220v.

    I was impressed with the Panasonic design and build quality used in the Prius Plugin EVSE as a level1 unit.
    The Panasonic Prius plugin EVSE is a bit of a pain to disassemble because major desoldering is required to get to the component side of the low voltage power supply board.

    Compared to the $260 upgrade service, I liked the support, open attitude ,options and price from the people over at open-evse .
     
    #7 IMkenNY, Feb 8, 2015
    Last edited: Feb 8, 2015
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  8. srl99

    srl99 Member

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    There was a time when that "upgrade" company was the only game in town, I have also had my issues with their attitude, although I believe if you had sent them your failed "upgrade" they probably would have repaired it (for free?). The instructables, if the same as the description on mynissaleaf basically powers the EVSE internal electronics from one leg of the (US) 240 VAC power. If you have a properly wired RV outlet you have a neutral, so you can use one hot and the neutral for the 120V for the electronics. The power to the car, however uses both hots. "Upgrade" replaces the EVSE power supply with a 120-240VAC power supply and adds a bunch of pixie dust. For my $$'s OpenEVSE is the way to go, they don't try to pull the rug over your eyes (Upgrade), there's support if you need it, and the prices are reasonable.
     
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  9. Redpoint5

    Redpoint5 Senior Member

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    For now, I've decided to only upgrade my Leaf EVSE unit, and have some varistors and a length of power cord being shipped to me. I will leave the Prius EVSE unit alone for the time being since there are no good instructions on how to modify it, and IMKen says it requires major desoldering to get to the components.

    It seems a little dishonest of the upgrade company to say "The upgrade process consists of new internal componentry". This implies that much or all of the internal components are replaced, when in fact the only thing that is removed is a single varistor (which is replaced with 2 varistors at less than $1 in materials).

    Yesterday I finished wiring a 6awg-4 line from my breaker panel to a 14-50R outlet and tested the voltages to ensure I wired it correctly. Once my parts arrive for the EVSE unit, I'll do the mod and plug into the new outlet.

    Now that I have a 50A 240v outlet, I'm feeling like it's wasted on the Prius. Now I'm considering selling the Acura TSX and buying a full EV to make better use of the outlet. That will require that I make room in the garage for 2 vehicles, and I'd like to resurface the floors. One project always leads to another!
     
    #9 Redpoint5, Feb 25, 2015
    Last edited: Feb 26, 2015
  10. bisco

    bisco cookie crumbler

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    i would like to do my garage floor...
     
  11. Redpoint5

    Redpoint5 Senior Member

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    I'm looking at concrete surface options, but the only thing affordable seems to be epoxy paint. I don't know how it would hold up to dragging floor jacks around and parking on it every day. My preference is a lighter color so that it brightens up the room, although it would be easier to stain and show dirt.

    Here are some of the products I'm considering:

    UGL 1-gal. Gull Latex Drylok Concrete Floor Paint-209154 - The Home Depot

    G-Floor 9 ft. x 44 ft. Levant Standard Grade Slate Grey Garage Floor Cover and Protector-GF55LV944SG - The Home Depot

    If I could get this stuff way cheaper, that's what I'd want in the garage.
    Husky 10 ft. x 22 ft. Coin Grey Universal Flooring-HK70CN1022SG - The Home Depot
     
    #11 Redpoint5, Feb 26, 2015
    Last edited: Feb 26, 2015
  12. bisco

    bisco cookie crumbler

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    i like the floor coverings, but mine pitches to the back unfortunately, and melting snow and slush sit there forever. epoxy has been discussed here before. seems to be pretty strong if done professionally, but i don't know about floor jacks and the like. my floors are 60 years old and would need a lot of oil removal.
     
  13. ELYKB

    ELYKB Junior Member

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    I was contemplating this video and wondering if the same can be done with the toyota cable adapter..

     
  14. bisco

    bisco cookie crumbler

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    absolutely it can, see the discussion at the beginning of the thread.
     
  15. ELYKB

    ELYKB Junior Member

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    any photos of the toyota evse internal wiring or board ?

    i'm waiting on my spare evse to arrive before I crack open the toypta one.
     
  16. bisco

    bisco cookie crumbler

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    not that i recall. maybe red point will jump in, he's probably done his by now. i don't recall anyone doing it themselves. there may have been a thread where someone opened it up and snapped a pic because it was broken, not sure though.
     
  17. Redpoint5

    Redpoint5 Senior Member

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    What vehicle did the EVSE you are waiting for belong to?

    I completed the Leaf EVSE conversion and decided to leave the Toyota unit alone. The only time it gets used is when I visit my parents.

    You'll be the first to get photos of the Toyota internals, and I'm very curious to see them.

    All OEM EVSE units are built similarly, with 120v being supplied to the logic side, and a contactor that can supply either 120v or 240v on the output. The main difference between the Chevy video and the Leaf instructions I followed is that the Chevy didn't have a varistor modification.

    I intend to get a used Toyota EVSE for ~$200 and modify it just to see how it works and maybe sell it for $300, but it looks like you'll have figured it out before me.
     
  18. Chazz8

    Chazz8 Gadget Lover

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  19. bisco

    bisco cookie crumbler

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    that's it!!!
     
  20. jerrymildred

    jerrymildred Senior Member

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    That one seems to have died on the vine before any actual pictures of the internals of the Toyota EVSE. I opened mine this morning for a quick look-see. Can't see anything behind a circuit board that's secured by 6 or 8 screws and an unknown amount of solder joints or other connectors. No time now for further investigation. And I'm not so sure I want to take any risks doing exploratory surgery on my only EVSE cable. Definitely getting the itch to do the conversion, though.
     
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