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Low cost shared charger with billing?

Discussion in 'Charging Standards and Infrastructure' started by twonius, Jul 19, 2018.

  1. twonius

    twonius Member

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    Hi,

    My office is considering putting in a plug (yaaay).

    Here's where it gets tricky

    Now the building could qualify for heavily subsidized chargers from SDG&E but they already don't have enough parking and therefore can't dedicate the necessary 10 spots needed to qualify for the program.

    We could put in a chargepoint or sema connect post in one of our allocated spots but the cost of those is so high relative to a normal EVSE ($4k-$6k vs $500) that we'd probably never pay enough in electricity over the life of the system to justify adding it just for the billing option.

    So is there a cost effective way for a limited number of users (lets say 10) to share an EVSE and pay for their own usage without going all the way to a full commercial setup?

    I've seen clipper creek has a system where you can tag in and out but I don't think it tracks usage, just controls access.
     
  2. twonius

    twonius Member

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    did some back of the envelope calcs and it looks like I use about 2000 kWh / year at the charger i use near work now.

    I'm probably the heaviest user in the office so this is like the high end.

    So it's a bit much to expect the company to eat (about $70/month) but with only 3 EVs right now it's not really enough to justify a commercial charger.
     
  3. David99

    David99 Active Member

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    Just install a few JuiceBoxes or Clipper Creek and everyone who charges keeps track of how much they charge and then pays their share. I'd assume people are honest enough.
     
  4. twonius

    twonius Member

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  5. miimura

    miimura Active Member

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    TurboDock has access control without monthly fees, but it looks like they may be out of production.
     
  6. swaltner

    swaltner Member

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    Nayax (credit card readers for vending machines) sells one for roughly $2k per “nozzle” with payment processing through credit cards and NFC (Apple Pay, etc...). EV Meter They have plans that don’t have monthly fees, but just charge a percentage of transactions.

    One suggestion I saw posted here was just use something like an OpenEVSE unit that displays how much power was used for the current (and all) charging session(s). Put a QR code on the EVSE with a sign giving a price of 10 cents per kWh through PayPal and let it go on the honor system. Compare your cash received to the electricity delivered to see if you need to lock the systems down. As you mention, it takes a while to recoup the higher cost of the EVSEs that have credit card capabilities.

    edit: forgot the link to the evmeter site
     
  7. twonius

    twonius Member

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    Yeah i think I'm going to pitch them on adding a few juiceboxes commercial (about $1k each) and the enterprise software to manage it.
    We'll need to add some kind of internet connectivity for them but a cell modem isn't that hard to source.

    It'd be nice if you could do the billing through an app and generate a 1 time code (or series of flashes like electric IMP) to start the machine but that's another business.
     
  8. ai4px

    ai4px Member

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    I got a DIN rail mount meter off eBay for $16 to track my water heater a few years ago. It has a relay contact output of 800 ticks per kWh. It would seem the thing to do would be to have a raspberry pi counting ticks and correlating them to an RFID reader sold by SparkFun. The 12v line that drives the contractor in the EVSE could also be used by the PI processor to know when to stop debiting against a particular RFID card. Don’t know what line of work your in or if anyone at your business could do that as a hobby.
     
  9. twonius

    twonius Member

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    If this was my house and not a shared commercial building I'd do it that way.
    But here we need a bit more of an off the shelf solution.


    I wonder if smarter EVSE's can read the VIN off the car over canbus?
     
  10. swaltner

    swaltner Member

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    That’s not possible in the J1772 standard.
     
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