CarCharging Reduces Amperage of Residential Charging Stations, For Safety Reasons

By · August 20, 2014

Blink home charging station

CarCharging, the group that acquired the Blink Network, sent an email today to owners of Blink-branded residential stations, warning about safety concerns. The company’s note said: “This concern is related to high temperatures, which can potentially cause overheating.”

CarCharging acquired the Blink Network in October 2013, and assumed the responsibility to provide service to EV drivers using Blink-branded charging stations. Many of those charging stations were supplied to thousands of EV owners as part of The EV Project. The project’s goal was to jumpstart EV sales in the early days of the plug-in car market, by providing free (or highly subsidized) residential charging equipment to more than 8,000 electric car drivers.

The EV Project, which launched in October 2009, was awarded nearly $100 million in support from the U.S. Department of Energy. The EV Project stop accepting applications for subsidized charging stations in March 2013.

Slower Charging

CarCharging’s email explained that, as a precaution, the company remotely reduced the amperage of specific charging stations to 24 amps. The email explained that, “In all cases where Blink L2 chargers have been rated to 24 Amps, there have been no reported high-temperature or safety issues.” CarCharging said that the reduction in amperage is expected to be temporary, until replacement parts are available.

While cars with 3.3-kilowatt onboard chargers will see no reduction in charging speeds, the current norm for electric cars is 6.6-kilowatt charging. Owners of cars using the Blink charging station with reduced amperage could potentially see a 15 percent drop in charging speeds. In other words, the ability for an electric car with a 6.6-kW charger to add, for example, about 23 miles of range in an hour of charging might be decreased to about miles added in an hour below 20 miles.

While that reduction is not significant for most drivers, questions about equipment safety a few years after installation, and the ability for CarCharging to remotely (and without owners' permission) alter the performance of residential chargers, are potentially greater concerns.


· · 3 years ago

I'm pretty sure the safety issues of Blink EVSEs was pretty well known in the EV community. I'm glad to see CarCharging taking action to protect people from potential fire hazards. As for their ability to remotely alter the EVSEs, wasn't that part of the EV Project agreement? Remote monitoring and control? The project was about more than subsidizing equipement. It was about gathering data.

· · 3 years ago

This reduction in charging current only affects plugins (EVs or Plug-in-hybrids) that have an on-board 6.6kW charger. Since the majority of plugins offered today have the cheaper 3.3kW on-board charger, this change will be invisible to them.

But for those EVs whose owner opt'd to have a 6.6kW on-board charger because of a larger pack or shorter time of use rate charge-window, this will affect them.

But by how much it will affect them is dependent on their AC source voltage, and applicable to the higher current charging during the first 80% of the charge. After 80% state of charge (SOC), the charging current is reduced dramatically (the smart on-board charger protects the battery pack).

The following only affects that 1st portion (0 to 80% SOC).

A charger supplied by 240VAC: A 6600 Watt charger (EVSE) would normally draw 27.5 Amps, which is now being reduced to 24 Amps ((1-(24/27.5)) * 100) = a ~12.7% increase in charging time on EVs with a 6.6kW on-board charger.

A charger supplied by 220VAC: ((1-(24/30) * 100)= 20% increase in charge time.

A charger supplied by 208VAC: ((1-(24/30) * 100)= 24.4% increase in charge time.

The majority of home have a 240VAC source. Some older homes are 220VAC, and businesses that are supplied with 3 phase power generally are at 208VAC (like at work or public garages, etc.).

So how much ccg's 'covering their butt, without any real fix to the weak Blink hardware design' affects drivers depends on their voltage source and the on-board charger their plugin has. And of course, what EVSE they are charging off of (i.e.: a funky Blink EVSE at home, but a fully operational non-Blink EVSE everywhere else.

The more you know, the better you understand 'What is Watt'.

· · 3 years ago

Blink and CarCharging have replaced cables that have been shown to overheat. Were those units turned down too? Was the action taken across the board? Also, what happens if your unit was not powered when they pushed out the change? Will it automatically be turned down after the unit phones home?

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