3 ms·

You just plug in, no card. The car identifies itself. It needs an internet connection to report the usage so it can be charged to the correct account. Gas stati

You just plug in, no card. The car identifies itself. It needs an internet connection to report the usage so it can be charged to the correct account. Gas stations obviously need a network connection of some kind too for card swipes to work. Otherwise you'd have to fall back to cash or manually writing down card numbers (is that even allowed anymore?) Almost all Superchargers are unmanned so no cash.

blt 6y ago
They could store the transactions in local memory until the connection is restored.
- kube-system 6y ago
  How do you know the account is valid, able to be charged, etc?
  - kwhitefoot 6y ago
    There are only half million Teslas so you can just distribute the VIN numbers of all of them with a single bit flag saying whether they are eligible for free charging and another bit saying that they have an account in good order. Twenty bytes per car should do it, say 10 MB of storage to hold enough information to say which cars are allowed to charge even if the network is down. Mind you in three years of owning and driving (70k km) my Model S I have never encountered a Supercharger station that was entirely out of order, just a few heavily used ones that have one or two stalls often not working.
  - blt 6y ago
    Send invoices to identifiable users, which go to collections if unpaid. Eat the cost for unidentifiable users. As long as you can fix any connection problem within a few days, the maximum value lost is limited by physics. People used to pay for stuff with checks all the time. It's similar to that.
- theshrike79 6y ago
  Would they store all of the valid credit card numbers in the world in local memory too? =)
Reason077 6y ago
EMV (chip/contactless) credit cards are capable of working without an internet connection, including PIN or device-based verification. Transactions get stored/batched on the payment terminal until the connection is available again. EV chargers often still require internet, however, as payment is via app or their own RFID card/dongle. Putting credit card readers directly on the chargers is a relatively recent (and not yet universal) improvement. Another reason for internet is so that chargers can report their availability status. In-car navigation or charging apps can direct you to locations with available chargers, avoiding ones that are fully occupied or out of service.
- modeless 6y ago
  That may be theoretically possible but I very much doubt any retailers have that set up to work properly. Around here the gas stations still verify your ZIP code. Superchargers could also store transactions in theory but I doubt it actually works there either.
  - Reason077 6y ago
    It certainly happens, very occasionally, here in the UK. You try to pay something with contactless but there's a long processing delay. The terminal will then time out and ask you to insert the card and enter PIN, and you will get something strange printed on the receipt like "CVM: offline PIN". You may then see the transaction pop up in your notifications a few hours later, or early the next morning. Also, some merchants do offline or semi-offline transactions as a matter of course. London Buses, for example, accept contactless payments via bank card. But the transaction must be processed very quickly and the mobile data connection is not entirely reliable - the bus could be in a tunnel or a coverage black spot. So what really happens is the transactions are batched and processed at the end of the day (this also allows them to do some post-processing for multiple-journey discounts, daily price caps, etc). Someone like London Buses isn't overly concerned about fraud because the transaction values are low. But they do have a way to blacklist cards numbers that are known to be bad.
- fastball 6y ago
  How do you verify there is enough balance in the account, etc? Pin+chip just verifies that the card is yours, not that the card can actually pay for anything. For example, you could use a VISA gift card with $0 balance to pay for things if you had a system that was accepting transactions while offline.

blt 6y ago

They could store the transactions in local memory until the connection is restored.

kube-system 6y ago
How do you know the account is valid, able to be charged, etc?
- kwhitefoot 6y ago
  There are only half million Teslas so you can just distribute the VIN numbers of all of them with a single bit flag saying whether they are eligible for free charging and another bit saying that they have an account in good order. Twenty bytes per car should do it, say 10 MB of storage to hold enough information to say which cars are allowed to charge even if the network is down. Mind you in three years of owning and driving (70k km) my Model S I have never encountered a Supercharger station that was entirely out of order, just a few heavily used ones that have one or two stalls often not working.
- blt 6y ago
  Send invoices to identifiable users, which go to collections if unpaid. Eat the cost for unidentifiable users. As long as you can fix any connection problem within a few days, the maximum value lost is limited by physics. People used to pay for stuff with checks all the time. It's similar to that.
theshrike79 6y ago
Would they store all of the valid credit card numbers in the world in local memory too? =)

Reason077 6y ago

EMV (chip/contactless) credit cards are capable of working without an internet connection, including PIN or device-based verification. Transactions get stored/batched on the payment terminal until the connection is available again. EV chargers often still require internet, however, as payment is via app or their own RFID card/dongle. Putting credit card readers directly on the chargers is a relatively recent (and not yet universal) improvement. Another reason for internet is so that chargers can report their availability status. In-car navigation or charging apps can direct you to locations with available chargers, avoiding ones that are fully occupied or out of service.

modeless 6y ago
That may be theoretically possible but I very much doubt any retailers have that set up to work properly. Around here the gas stations still verify your ZIP code. Superchargers could also store transactions in theory but I doubt it actually works there either.
- Reason077 6y ago
  It certainly happens, very occasionally, here in the UK. You try to pay something with contactless but there's a long processing delay. The terminal will then time out and ask you to insert the card and enter PIN, and you will get something strange printed on the receipt like "CVM: offline PIN". You may then see the transaction pop up in your notifications a few hours later, or early the next morning. Also, some merchants do offline or semi-offline transactions as a matter of course. London Buses, for example, accept contactless payments via bank card. But the transaction must be processed very quickly and the mobile data connection is not entirely reliable - the bus could be in a tunnel or a coverage black spot. So what really happens is the transactions are batched and processed at the end of the day (this also allows them to do some post-processing for multiple-journey discounts, daily price caps, etc). Someone like London Buses isn't overly concerned about fraud because the transaction values are low. But they do have a way to blacklist cards numbers that are known to be bad.
fastball 6y ago
How do you verify there is enough balance in the account, etc? Pin+chip just verifies that the card is yours, not that the card can actually pay for anything. For example, you could use a VISA gift card with $0 balance to pay for things if you had a system that was accepting transactions while offline.