Considering living with 120V

So every situation is different but I have an electric rate that is pretty unusual.....

Peak - 7 cents, Off peak - 5 cents. Off is 9p-10a summer ; 9p-6a and 10a-1p in winter.

The unusual part is a Demand charge of $4-5 a kw for the highest 15 minute total use during peak. So if you charge with 6 kw while the 3 kw a/c unit is running, while the 3kw dryer is running - there is a $60 charge that month. Solar panels are getting installed with net metering so the majority of the bill will be the demand charge. Probably 8 months of the year, demand will be the only charge.

So obviously charging at night makes the most sense. If you had to charge during peak, it makes sense to charge as slowly as you can - ie with the 120V trickle if you can stand it.

After 2 weeks, sure I'd like to charge faster but it hasn't been a practical issue. I don't foresee a significant problem with getting to full over night.

From what I can gather, charging as slowly as possible is best for the battery. It also is less efficient. Trying to find a balance is what I am looking for.

I am considering getting the EVSE upgrade and having it set to 1 kw or 1.5 kw as a compromise - but it that just crazy? Not that I want to do it often but I do have a level 2 charger 1/2 mile from the house (not free). We are a 2 car family with an ICE.

Depends on your driving needs. If under 50 mi/day, shouldn't be too tough (except in inclement weather). If you get the EVSEupgrade, then you can still plug into L1 if you'd like. I'm pretty grid friendly, L1 charging a couple of hours each night, and then overriding the timer as needed. One warning, driving multiple days above your average (say 75 mi), can get you behind on the charge. In these cases you might need to switch to your other car, or not make a trip. Here are some more L1 vs L2 discussions:
http://www.mynissanleaf.com/viewtopic.php?f=34&t=10776&p=247635#p247635

Sounds to me like you would want a 3.3kW L2, or maybe the EVSEUpgrade V1 which is 2.88kW. Those options should allow you to fully charge the car, in pretty much all circumstances, off-peak, so no demand charge worries. Since your AC runs at 3kW, daytime use on days without AC wouldn't increase your bill. Plus, you could always fall back to plugging into 120v, if circumstances dictated that.

I suppose it depends on your daily needs. I charge on 120V 95% of the time because my wife hogs the 240V EVSE that we have mounted in the garage for her Volt. However, there are days that I need the faster charge and it would be inconvenient if it were not available to me. Not to say that I couldn't make due with 120V permanently, I just wouldn't like it.

Consider a Leviton 160 to limit power to 4kW. Or even 12a evse upgrade to be under 3kW.
If you use the timer you can charge overnight from 2a to 7a when other stuff is probably off.
Save the 6kW charging for when you are on the road.

5 cents and 7 cents makes me crazy even with demand charge.

Summer here is 15 cents super off peak and 60+ cents on-peak.

120V (a.k.a. trickle charge) is fine. I did it myself for almost a month before I got my 240V Evlink installed. But a few notes:

1) I, too, thought that 120V charging was better for the battery than 240V charging, since 240V is better than 440V (Quick Charge). But there is no evidence to support this. Everything suggests that the LEAF battery is happy with 240V or 120V.

2) 120V actually costs you a little more. There is a fixed electrical cost to charging - it applies no matter how fast the current is flowing. Thus charging with 120V actually uses a little more electricity (maybe 10%) than the equivalent charge with 240V.

3) It may seem that 120V is fine now, but if you get a 240V charger you may find that you use the LEAF for more miles and your ICE car for fewer miles. It's hard to say - this is definitely a YMMV situation. For us we found that the 240V charger allowed us to use the LEAF for additional round trips each day. In the most extreme case the LEAF went 141 miles in a day using just the home charger.

Assuming you have the 6 kW on board charger, I recommend the Revision 1 EVSE upgrade (12 amperes at either 120 or 240 volts) and a full 30-ampere wall-mount L2. This would give you the flexibility to charge quickly during off peak times and choose from either 1.44 kW L1 or 2.88 kW L2 using the EVSE upgrade depending on your demand situation when charging on peak. I think you might find the 6 kW L2 charging to be quite useful to get a quick charge during the mid-day off-peak period in the winter when battery capacity is lower. As others have mentioned, L2 charging is slightly more efficient. Also, I think you will use the LEAF more if you have L2 charging at home.

I have a similar rate plan except the demand is for 1 hour (60 minutes). I have a programmable load controller which turns off the water heater, dryer, and the compressors for the heat pumps in sequence to keep the demand down. I have the AeroVironment for my normal off-peak charging and the Revision 1 EVSE upgrade for portable use. I can use the upgrade unit if I need to charge on peak at either L1 or L2 depending on my demand level for the month. Since I have the 3.3-kW onboard charger, I am watching the availability of small quick chargers with 240-volt input so I could charge quickly on weekends.

For comparison, my peak time is 9a to 9p Monday-Friday and the rates are:
Winter peak $0.05587/kWh plus $9.40/kW; off-peak $0.03967/kWh
Summer peak $0.07330/kWh plus $13.55/kW; off-peak $0.04083/kWh

Gerry

davidcary said:

I am considering getting the EVSE upgrade and having it set to 1 kw or 1.5 kw as a compromise - but it that just crazy? Not that I want to do it often but I do have a level 2 charger 1/2 mile from the house (not free). We are a 2 car family with an ICE.

Click to expand...

The good news is we now have an upgrade available that allows user-programmable amperage settings. For the 6.6kW (6kW actually) 2013 LEAF, you can adjust your output from 6 to 20 amps in 1 amp increments. You'll be able to adjust your output as needed to avoid the demand charges, but still be able to charge faster if you ever need to.

We will soon have the new options listed on our site, but for now, just order a standard Rev2 upgrade and then drop us a note indicating what year and model your LEAF is.

-Phil

I'm surprised to hear of demand charges on residential rate plans. I'm not familiar with them in my area (PG&E) except on commercial schedules. (See http://www.pge.com/tariffs/rateinfo.shtml" onclick="window.open(this.href);return false;.)

http://www.douglaspud.org/Service/2013RatesJanuary12013.aspx" onclick="window.open(this.href);return false; (which has incredibly cheap electricity) has some but they don't seem to kick in until you pass a 50 KW demand.

You should consider a charger like the Siemens VersaCharge which has two features that will help.

1. You can delay the start of charging 2/4/6/8 hours with a quick button press, and at 240V you should be able to charge to 80% after midnight with no problem, every night and full charge quickly when you need it.

2. You can set the maximum charge wattage to 1.8/3.6/5.4/7.2 KW (harder to adjust, but doable).

Setting to 3.6 would limit the maximum surcharge to ~$18 a month based on the car charging even if you got the timing messed up.

If you are doing 300 KW (1,000 miles) charging at 240V would save at least 30KW which is $2.10 a month.

$0.07 cents a KW? Wow. We're stuck at $0.16 cents here so getting the 240V charger was a no brainer based on efficiency alone.

Wait - Phil you are going to have a fully adjustable upgrade. Now we are talking. I've been jealous of the Tesla since it has onboard adjustable rates.

Just to be clear - the demand charge is the highest for the month. So mess up one day in a month and you get the charge. I was just throwing numbers out but if both a/c units are running, oven and dryer.... well you get the idea.

That is where I am challenged. I can always shut off the a/c but if I forget 1 day in a month....

This plan is foreign to CA. This is NC and foreign to most around here. It is required to get a rebate for a solar installation from the utility. The rebate is $5k and I am only committed to the plan for 5 years. Since that almost covered my electric bill for 5 years, I am not complaining - just adjusting to it.

Yeah - 5 cents to charge is pretty killer. Basically 1 cent a mile even if it is really 1.2...

Perhaps putting a Off-Timer on your high-wattage
circuits might help to remind you, because you
would need to override the timer(s) to use the oven,
dryer, EVSE, etc.?

Phil,
How does the user change the Max-Amps settings?

How does the user see what setting is selected?

Must it be reset each time the EVSE is unplugged from the wall?

Can my old 2011 Nissan (v1 upgraded) EVSE get this "R3" mod?

Great news, please keep up the good work.

One point not mentioned, is that when you are charging at lower kW rates you are not only wasting energy, but that energy is being used by mechanical systems with wear factors.

The coolant pump (s) in your LEAF should probably be expected to have a shorter calendar life at slower charge rates.

Whether your LEAF will ever need a repair or replacement of a coolant pump, and what that could cost, are probably questions you don't really want to know the answer to, IMO.

Given the known cost savings in charging efficiency, and (possible) unknown cost in repairs, If you have access to 240V, I believe the very low costs of an L2 EVSE is likely to be a very good investment.

davidcary said:

So every situation is different but I have an electric rate that is pretty unusual.....

Peak - 7 cents, Off peak - 5 cents. Off is 9p-10a summer ; 9p-6a and 10a-1p in winter.

The unusual part is a Demand charge of $4-5 a kw for the highest 15 minute total use during peak. So if you charge with 6 kw while the 3 kw a/c unit is running, while the 3kw dryer is running - there is a $60 charge that month. Solar panels are getting installed with net metering so the majority of the bill will be the demand charge. Probably 8 months of the year, demand will be the only charge.

So obviously charging at night makes the most sense. If you had to charge during peak, it makes sense to charge as slowly as you can - ie with the 120V trickle if you can stand it.

After 2 weeks, sure I'd like to charge faster but it hasn't been a practical issue. I don't foresee a significant problem with getting to full over night.

From what I can gather, charging as slowly as possible is best for the battery. It also is less efficient. Trying to find a balance is what I am looking for.

I am considering getting the EVSE upgrade and having it set to 1 kw or 1.5 kw as a compromise - but it that just crazy? Not that I want to do it often but I do have a level 2 charger 1/2 mile from the house (not free). We are a 2 car family with an ICE.

Click to expand...

your off peak hours are so generous, I would find very little reasons to not charge at 240. the EVSE upgrade is a great deal and versatile, portable and adjustable.

if that is not enough, respond and i will provide some synonyms for the words above

edatoakrun said:

One point not mentioned, is that when you are charging at lower kW rates you are not only wasting energy, but that energy is being used by mechanical systems with wear factors.

Click to expand...

+1 I recommend charging at L2 rates off-peak.

davidcary said:

The unusual part is a Demand charge of $4-5 a kw for the highest 15 minute total use during peak.

Click to expand...

What hours are considered peak?

Might be worth looking into an energy management system to automatically load shed.

garygid said:

Phil,
How does the user change the Max-Amps settings?

How does the user see what setting is selected?

Must it be reset each time the EVSE is unplugged from the wall?

Can my old 2011 Nissan (v1 upgraded) EVSE get this "R3" mod?

Great news, please keep up the good work.

Click to expand...

There is a simple procedure that uses the handle release button to set the amps. The EVSE indicates the setting with a blink code. We are working on an upgrade for existing Rev1/Rev2 owners, but it isn't ready yet. We will announce it when we have something ready. The new Gen-2 (2013) EVSE is equipped with non-volatile memory, so we are able to save the settings if power is lost, but unfortunately the Gen-1 hardware you have (2011-2012) does not have this feature. However, it will keep it's setting as long as power is not lost.

We are going to add the new options to our web site as soon as we can. Right now sales of 2013 LEAFs are very high and it's keeping us working all day and all night to keep up, so until things get less crazy around here, we may not have time to work on the solution for existing Rev1/Rev2 units.

-Phil

davidcary said:

The unusual part is a Demand charge of $4-5 a kw for the highest 15 minute total use during peak. So if you charge with 6 kw while the 3 kw a/c unit is running, while the 3kw dryer is running - there is a $60 charge that month. Solar panels are getting installed with net metering so the majority of the bill will be the demand charge. Probably 8 months of the year, demand will be the only charge.

Click to expand...

As a PG&E customer I want your plan where I have to worry about a $60 electric bill! :lol:

What is your solar output? Does it reduce your net consumption for demand calculations? I.e, if your solar is putting out 6kW and you're consuming 8kW, is the demand calculation 2kW?

Nubo said:

What is your solar output? Does it reduce your net consumption for demand calculations? I.e, if your solar is putting out 6kW and you're consuming 8kW, is the demand calculation 2kW?

Click to expand...

Isn't that obvious? A hookup that fed your solar output through their meter would be insane! And they can't measure what they never see.

Ray