Blink to Charge by the (Kilowatt) Hour: What is the Best Way to Charge for Your Charge?

Today, Blink announced a switch, where possible, to charging for electricity by the Kilowatt Hour (kWh) instead of by charging time. Is this better or worse and what are the pitfalls to each approach?

Blink EV Chargers at Coffe ShopHistorically, EV charging at public stations, where not free or included in the parking charges, has always been priced by the hour. The cost has ranged from as little as $0.50 for Level 2 to as much as $7/hr for DC fast charge. The problem is that, not all cars charge at the same rate and to illustrate that, let’s look at the mid-point, let’s consider a $2.50/hr charge on a typical charging station that you might find all over America – for the technicaly minded fact checkers, we’re looking at a 30A unit wired into a 208V leg of a 3-phase circuit.

Traditionally, it doesn’t mater if you suck or sip the power, it’s the time connected that matters:

Car Charge rate How long to charge up Cost
Mitsubishi i-MiEV 2.9kW About 5 hours $12
Nissan Leaf (basic model) 2.9kW About 8 hours $20
Nissan Leaf (latest model) 6.2kW About 4 hours $10
Ford Focus Electric 6.2kW About 4 hours $10
Tesla Model S 85 6.2kW About 14 hours $35


Blink is proposing to charge instead by the amount of electricity consumed. For Level 2, they’re proposing between $0.39 to $0.79 so, again, looking at a midpoint of $0.59, let’s look at the same cars:

Car Charge rate How long to charge up Cost
Mitsubishi i-MiEV 2.9kW About 5 hours $9
Nissan Leaf (basic model) 2.9kW About 8 hours $14
Nissan Leaf (latest model) 6.2kW About 4 hours $14
Ford Focus Electric 6.2kW About 4 hours $14
Tesla Model S 85 6.2kW About 14 hours $51


Are you seeing a jumble of pluses and minuses? We are too.

And there’s more

We keep saying ‘Where possible’ Blink will switch to rates by the electricity consumed and that’s because, not all states in the US even permit this kind of operation. States like California, Colorado, Florida, Hawaii, Illinois, Maryland, Minnesota, New York, Oregon, Utah, Virginia, and Washington, along with the District of Columbia permit companies like Blink to sell electricity by the kWh whereas others like New Jersey don’t. We think that is odd. Imagine if you couldn’t buy gasoline by the gallon but instead were charged for how long it took to fill the tank?

Further more, the rate will vary from state to state and as Blink put it, “{on the} individual’s membership status” whatever that means.

Lastly though, in a clearly positive move, Blink announced that “To enhance our time-based charging policy, we will also reduce the time increment for stations owned by Blink and operated on the Blink Network located in states where kWh pricing is not permitted. Time-based charging fees will no longer be rounded to the nearest hour, but rather, up to the next 30-second interval. ” We can all agree that’s a good move.

Which is best?

Right now, it’s clear that there’s no clear winner, no cheaper solution whilst prices vary for both by-the-hour and by-the-amount-consumed.

We at Transport Evolved think the charging by the electricity consumed feels the more fair solution but it’s clear that there are exceptions.

Overall, we think this raises more questions than it answers. Which would you as a consumer prefer? How do the site operators feel about this move? Will this promote more charging-and-abandoning? Help shape the debate with your thoughts below.


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  • JohnCBriggs

    If they can’t charge per KWH, perhaps they can charge based on time and level of service. One rate for 2KW, another for 3KW, a third for 4KW.nnNot charging by KWH, oh no. Charging based on time and level of service.

    • Michael Thwaite

      I wonder if they’ve tried that but found it not legal?

      • JohnCBriggs

        What, too thinly veiled 🙂

    • Charging by the kWh can accommodate the “time value” of faster charging by offering different price points based on the charging rate. nnEg: 3 kW charging rate at an EVSE would be priced lower than 6 kW EVSE; and 10, or 20 kW priced higher per kWh.nnFees based on time periods are complex as “speed of charging” changes based on SOC (state of charge) and battery capacity related to the physics of charging procrss. This is more noticeable for DCFC as the EVSE are capable of much higher charging speeds than on-board AC chargers. (charging speed starts to become limited when EVSE can charge a battery in udder 90 min; both for AC & DC)

    • Lance Pickup

      This is the way I think it should be period, not just in places where they are not allowed to charge by kWh.nnnWhy? Because we need a way to motivate vehicle owners to move their vehicles when they are done charging, or even tapering off. We have users in my area that stay connected to a DC fast charger for 90 minutes filling their EV up to 100% even though there is an L2 station located in the next spot over. They are taking up a valuable resource for an extra hour they do not need to. A per kWh charge would not motivate them to free up that resource the same way a time-based fee–with different tiers for service levels–would. I.e. you would pay a significantly higher per minute rate while connected to a DC fast charge than you would while connected to an L2 pulling 6.6kW max.nnnI acknowledge that if your tiers were set up such at 3.3kW L2 charging was half as expensive (per minute) than 6.6kW L2 charging (thereby creating a total charge fee that works out to effectively be per kWh), that the 3.3kW vehicle will take up the spot twice as long as the 6.6kW. Therefore I do think it’s fair to adjust the rates SLIGHTLY such that the 6.6kW user gets a better deal for using the higher rate, and this entices drivers to purchase vehicles with faster charging capability that would use public chargers more efficiently.nnnWhile the argument against this may be that it makes it too complicated, we already have 3 grades of gasoline at most US gas stations (4 if you count diesel). I don’t think you’d need too many different charging rate tiers (up to 5kW, up to 10kW, up to 20kW on the AC side and a 50KW and 100KW DC rate tier). Plus the charger could generally just figure out the fastest rate, so it’s not even like any buttons would need to be pushed–it’s basically just the signage that would have to show you the different rates.

      • JohnCBriggs

        Those are some excellent point.nnIt does make me wonder if they chargers should simply cut people off at a certain point, e.g., you are at 90%, you are done, move your car.

  • vdiv

    It could be worse, like eVgo. They charge you a subscription per month regardless if you can use any of their charging. I’d rather pay for a service delivered, not a service promised.

    • Michael Thwaite

      Well put, but, I wonder, would you get into the EVSE business not knowing if you were going to get any money this month?

      • vdiv

        You’d have to earn your customers’ trust. Many start-ups begin by offering a free or a deeply discounted service.

  • Martin

    I think it’s a good move in the right direction, real question is why do some states not allow charging by the KWh for electricity supplied decent meters have been available almost from the start of the use of AC systems over a hundred years ago. I knew that the legal system is sometimes slow but this is more than most peoples life time. It’s time legislators moved into the 21st century and got rid of all these obsolete lawsnI

  • Dreck Sheisse

    It’s crazy that there are places where you can’t charge by KWH.nI think this was to keep the power companies’ monopolies in places where they charge a monthly line charge, much the same as if you weren’t permitted to buy your own cable or DSL modem, or could only rent your cellphone.nYou can buy your own KWH (power) meter, and they are certified and very accurate. The cost is less than $100 for single phase. Somewhat pricier ones have digital memories, etc.

    • Lance Pickup

      I don’t think it’s a lack of technology, but rather a regulatory issue. If you charge by the kWh, you would then fall into a a regulatory classification alongside utilities, meaning you would have your rate tariffs set by the applicable regulatory agency, even if that means that you no longer have a viable business model since those rates are set up typical household (or larger) volumes. True, perhaps the regulatory agencies could (and should) create a special EVSE tariff with different rates & flexibilities.

  • For ‘classic’ LEAF owners the cost drops comparatively if per kWh pricing is used. For those of us who live in states where that isn’t allowed, the cost has increased 140%. My last charging session cost me 19c per mile. 7c more than a gasoline vehicle. nnnPublic charging in ‘per hour’ states is now firmly in the ’emergency use only’ category. If we hardly use them, eventually they will go away and there will be no emergency use stations to be had.

  • GodMk2

    I don’t know why they can’t get this right. The tariffs should have 2 components.

    1) An availability charge to cover infrastructure costs and to get you to move on rather than parking but not charging. Charges per minute. Its a flat rate which will mean it costs slower charging cars more, but we have to think of the availability for all service users.

    2) An energy delivered charge. Charged by kWh at a premuium over residential rates to discourage people charging in the daytime away from home when they don’t need to.

    Its entirely possible to stick in some 16Amp and 32 amp chargers alongside each other and price them differently. As well as some rapid 50kW chargers. 😉