2014 July Plugin Sales Discussion : Leaf 3019 , Total 10533

[bbrowncods]

one can only guess but I was hoping that Nissan would go with a 10 KW home charging option. That way I could just go with an Electric Stove adapter to replace my electric Dryer adapter with my EVSE upgrade version 3

10 KW is not going to happen on a 30A circuit. 50A circuit will be the minimum. Todays 6.6KW Leaf is doable on a 30A circuit, although that is maxed out. Probably why they those 6.6KW as the limit.

 

[DaveinOlyWA]

one can only guess but I was hoping that Nissan would go with a 10 KW home charging option. That way I could just go with an Electric Stove adapter to replace my electric Dryer adapter with my EVSE upgrade version 3

10 KW is not going to happen on a 30A circuit. 50A circuit will be the minimum. Todays 6.6KW Leaf is doable on a 30A circuit, although that is maxed out. Probably why they those 6.6KW as the limit.

just looked and my stove is 50 amp...

 

[Stanton]

When the battery capacities double, home charging at 120VAC and obtaining the special power rates will be impractical.

Many people have found that home charging at 120V is impractical with the current sized batteries. 220V 15 Amp is twice the power, and is likely to fit into all but the oldest of homes.

I tell anyone considering buying an EV to use 220v EVSE's as a long term solution. As was mentioned, the 6.6KW Leaf is doable on a 30A circuit, which is probably why they chose 6.6KW as the (new) limit. Yet another example of why the Leaf was "designed for the masses".

 

[DaveEV]

Many people have found that home charging at 120V is impractical with the current sized batteries. 220V 15 Amp is twice the power, and is likely to fit into all but the oldest of homes.

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.

Every home has at least a 100A service panel, but you are very rarely going to draw anything close to that even with all-electric appliances. But standard load calculations would limit you to anything significantly more than a 40A circuit at most for a charging station and often much less.

But if you had a charging station that monitored total house current draw you could adjust the pilot signal on the EVSE to account for that allowing for significantly higher rates of charging on a 100A service panel than you would otherwise get. House pulling 60A? Limit the EVSE to 20A. House pulling 10A? Limit the EVSE to 70A.

This is going to have to happen sooner or later as more houses get EVs - especially as they get 2nd and 3rd EVs and want to charge them all at the same time during off-peak hours to take advantage of utility rates.

 

[mctom987]

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.

 

[DaveEV]

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.