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only 53% gain on DC QC in 30 minutes?

Posted: Mon Aug 21, 2017 2:08 pm
by hackdroot
So I had to make a long run in my leaf today and decided I needed to stop at one of the EVgo QC stations to make my range. I've only used QC once and that was when I purchased the car and was driving it home.

I plugged in the car , SOC at 38%, and went to the local shopping center to kill time and returned 30 minutes later. I was surprised to see that the car had only charged up to 91% in that time. Is this normal? I was only able to get a charge increase of 53% in 30 minutes? I understand that the impedance of the older pack can affect charging, but the available capacity of the older pack should negate some of that, I would think. I had plenty of juice to get home, but just was curious of what others experiences are.

Re: only 53% gain on DC QC in 30 minutes?

Posted: Mon Aug 21, 2017 4:35 pm
by LeftieBiker
The charge begins to taper to L-2 after, I think, 80%.

Re: only 53% gain on DC QC in 30 minutes?

Posted: Mon Aug 21, 2017 5:07 pm
by alozzy
I personally don't think it's good EV etiquette to charge past 80% on DCFC/DCQC, especially if others are waiting. In fact, I wish the DCFC providers would configure their machines to automatically disabled charging (i.e. when the charging rate drops below 10 kW), as that would encourage people to switch over to an L2 when they want to charge beyond 80% SOC.

Incidentally, when traveling longer distances you'll want to limit charging to around 80% SOC anyways, as it's faster to do that when multiple charge cycles are needed. I typically use a charging pattern that results in 12kWh to 13 kWh discharge between charging stops, as that way I can charge up to 80% in under 30 mins (typically 20 mins) before starting the next leg.

Another way providers could encourage people to do this would be to set the DCFC charge cost to double the cost of L2 charging, or even better to provide free L2 charging for up to an hour. That way, for those that want to charge to 100%, the marginal cost would be very low (or free)