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ChargePoint charge rate unreliable

I am using a ChargePoint model CPF25 charger capable of over 7kW, but delivering much less. Sometimes it delivers 18-19 mi/hr while other times it's only 14. Has anyone seen this variation and found a way to motivate the vendor to fix it?
The lower charge appears when my ms slowly ramps up charge current and detects a large voltage drop. A warning message appears about a defective extension cord, but I don't have one. Instead of receiving 32 amps, the ms limits charging to 24 amps and delivers only 14 mi/hr. No one else is charging near me.

At a 1 amp charge (light load), voltage is 209. As current ramps up, voltage steadily declines to 194. This is an indication of excessive resistance somewhere in the line or connections. Is a 15 volt drop normal; acceptable to NEC?

I'm not the charger operator so am getting a deaf ear from ChargePoint Support.
 

Rocky_H

Well-Known Member
Feb 19, 2015
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8,987
Boise, ID
At a 1 amp charge (light load), voltage is 209. As current ramps up, voltage steadily declines to 194. This is an indication of excessive resistance somewhere in the line or connections. Is a 15 volt drop normal; acceptable to NEC?
I've heard similar from a lot of public charging stations. They have really long weak wiring runs, and have that kind of excessive voltage drop. There's nothing you can do to fix the installation, but the voltage drop scales with the number of amps, so turn down the amps in your car some to find a level that won't trigger the car's safety lowering. So instead of trying 32, and it lowers it to 24, try using something like 28 or 29 amps, and it may stay there the whole time, which is more than if it dropped to 24.
 
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I've heard similar from a lot of public charging stations. They have really long weak wiring runs, and have that kind of excessive voltage drop. There's nothing you can do to fix the installation, but the voltage drop scales with the number of amps, so turn down the amps in your car some to find a level that won't trigger the car's safety lowering. So instead of trying 32, and it lowers it to 24, try using something like 28 or 29 amps, and it may stay there the whole time, which is more than if it dropped to 24.

Rocky, that's an excellent idea. Thank you, I'll try your suggestion by lowering amps in small steps to avoid protection mode.
 

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