mctom987 said:
drees said:
Smarter charging stations could allow significantly higher charge levels even on old homes by limiting available charging power depending on how much power the rest of the house is using.
That's not a bad idea.
100A current transformers cost $100. ~$200 for high precision (probably unnecessary outside of billing uses)
PG&E has open APIs to gather the data needed to achieve this through "the internet of things", unfortunately, it's not real-time, and thus won't work.
I don't know what the response time would be for the pilot signal/car/evse, but I can imagine this not being a surefire solution. Car charging at 70A and you turn the electric range on? BOOM! Just tripped the SER breaker.
Way cheaper than $100, try $34: http://www.brultech.com/home/store/product.php?id_product=48" onclick="window.open(this.href);return false;
Well, the range is typically very short duty cycle - a 100A breaker won't trip at 120A instantly. But yeah, charging at 70A with a 50A appliance is probably not the best idea, but charging at 50-60A would probably be fine. Either way, I believe most cars should respond to changes in the pilot signal very quickly. Worst case if you discover an overload, disconnect the pilot signal and the car will stop charging immediately, then restart charging with a lower pilot.
I still wish that all plug-ins were 30A capable - even with a small-battery plug-in like the Prius or smaller-battery like the Ford PHEVs, I can think of lots of instances where charging the Prius in half the time (45 minutes vs 90 minutes) or an Energi in 75 minutes instead of 150 would give you a good boost in EV miles driven.
But would 30A charging significantly boost sales? On PHEVs, probably not, but I think it would on EVs. I still don't understand why GM doesn't at least make a 30A OBC an option on the Spark or Mitsubishi with the iMiEV, for example. I have family members that have each car and having 30A L2 charging would be a significant benefit.
Of course, with higher power plug-ins available, the need for smarter power-sharing setups only becomes more desirable. I know that i will likely opt to go
The Hydra route when I get another plug-in rather than another EVSE - with a 125A panel I simply don't have room for another EVSE circuit.