Average LEAF only Charges 2 hrs a day! INL

Did you know the average LEAF is plugged into a Charger for 9 hours but only charges for 2 hours a day?

I went to an EV conference last week where Idaho National Labs presented data collected from the EV Project. They had hard data from 956 Nissan LEAFs which they were to collate with data collected from the residential BLINK units.

Frankly I was very surprised, as my wife and I often drive 70-80 miles per days around Thousand Oaks & Los Angeles. So we are charging many more hours than this.

The PG&E speaker at the conference took this data and then said that Level 1 charging will be sufficient for most EV drivers. I thought this was crazy...

Here is the full report http://avt.inl.gov/pdf/prog_info/TheNetworkedEVSanFranOct2011.pdf" onclick="window.open(this.href);return false;

Neal

keep in mind that this data is coming from Blinks and everyone on this board knows how unreliable they are!

Garbage in..... Garbage out!

That would be close for me. I probably charge for about 3 hours, 4 days a week.

I bring the average way down as I charge 2-3 hours twice a week.

I gotta get out more! :shock:

DaveL said:

keep in mind that this data is coming from Blinks and everyone on this board knows how unreliable they are!

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Sounds about right for me, and in this at least my Blink has always seemed to be reliable in reporting statistics. It's hard to tell recently since Blink has "improved" their web portal to make the data much less accessible.

Two hours sounds a little low for me, but my charging rate is also a little low. I don't have a Blink or any way to measure kW at the wall, but with the 80% charge I almost always use there probably isn't much taper at the end of the charge. So with my 2.9 kW EVSE I can get nearly 5.8 kWh at the wall in two hours, or about 4.8 kWh at the battery. Since I drive an average of 22 miles/day, I would have to get 4.6 m/kWh to charge in 2 hours. My lifetime average is actually 3.9 m/kWh, so I'm guessing my average charge time per day is about 2:20. (My real charge times are higher than that because I don't charge every day.)

If my EVSE supported the full 16A that the LEAF's charger can pull, I would be well under 2 hours.

Ray

Neal said:

Did you know the average LEAF is plugged into a Charger for 9 hours but only charges for 2 hours a day?

The PG&E speaker at the conference took this data and then said that Level 1 charging will be sufficient for most EV drivers. I thought this was crazy...

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Yes, it is crazy for two reasons:

1) L1 charging is less efficient
2) While L1 would likely be fine for charging at night for most people, it is woefully inadequate for opportunity charging on a long drive. I drive from West LA to Claremont (50 miles one way) about once a week. L1 charging for 5 hours while I am hiking Mt. Baldy adds about 5 KWh, which isn't enough to get back comfortably without running the battery lower than I care to do. L2 is more than sufficient to top off.

Sound right for me too. I charge about 2 hours a day. I have never charged more than 5 hours.

My typical Blink charge is just under 5 hours for 80%, and under 7 hours for 100%.

Sure, L1 would be fine, except that SDG&E gives me only five hours to charge on Super-Off-Peak rates.
So sometimes I have to cut it short even with L2.

L1? No thanks.

i charge about 15-18 hours a week. so that is not far off for me.

These are somewhat different numbers than Nissan has released. Nissan has said the average daily driving is 37 miles rather than 31 miles. Not a huge difference but not the same. In either case the two hour charge can't be right because with a 3.3 kW charger you can't get the 10-12 kWh you need in two hours.

Very interesting presentation though with lots of facts.

Neal said:

Did you know the average LEAF is plugged into a Charger for 9 hours but only charges for 2 hours a day?

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That sounds about right. My own data shows that over 41 240V charge events, the average charging time is 2.6 hours with an average of 4.5 SoC bars remaining.

That average number of remaining SoC bars also confirms my experience over the first three month of LEAF ownership that charging on 120V was not so time consuming as to be noticeable: a full recharge does not require more than overnight. That's effectively the same as my current experience with 240V charging.

SanDust said:

These are somewhat different numbers than Nissan has released. Nissan has said the average daily driving is 37 miles rather than 31 miles. Not a huge difference but not the same. In either case the two hour charge can't be right because with a 3.3 kW charger you can't get the 10-12 kWh you need in two hours.

Very interesting presentation though with lots of facts.

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If L2 restores 15 mph charging, the 31 miles = about 2 hours. 37 would be closer to 2.5 hours.

My average during 6 month ownership has been as reported 2 hours and I have Blink unit, but then my average daily mileage is 22 miles which far below Nissan's average.

SanDust said:

In either case the two hour charge can't be right because with a 3.3 kW charger you can't get the 10-12 kWh you need in two hours.

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LOL, of course you can! Who said you need 10-12? I've recharged to 80% many times in less than two hours! If it's at 5 bars left (48% actual), mine will charge 5 bars in about 100 minutes.

smkettner said:

If L2 restores 15 mph charging, the 31 miles = about 2 hours. 37 would be closer to 2.5 hours.

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If you have a 3.3 kW charger then, given that there will be an unavoidable loss of 10% inherent in the electrical to chemical conversion, assuming no other losses you can put 2.97 kWh of charge into a battery in one hour. In two hours that's 5.94 kWh. Going 30 miles on 5.94 kWh would require you to use less than 200 wh/mile, which isn't realistic. Going 37 miles would require you to use 160 wh/mile, which is surreal.

IBELEAF said:

My average during 6 month ownership has been as reported 2 hours and I have Blink unit, but then my average daily mileage is 22 miles which far below Nissan's average.

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This is what you'd expect from a careful driver. You're using about 260 wh/mile so I'd say that you're not driving very aggressively and you're not driving very fast.

LEAFfan said:

LOL, of course you can! Who said you need 10-12? I've recharged to 80% many times in less than two hours! If it's at 5 bars left (48% actual), mine will charge 5 bars in about 100 minutes.

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Charging 5 bars in 100 minutes would be quite the trick. Even if you only have 20 kWh usable that would mean you're ending up with 8.3 kWh in the battery in a little more than an hour and a half (5/12 X 20 = 8.333). Can't happen unless you believe that 1.5 X 3.3 = 8.3. Even if the charger was 100% efficient, which it isn't, you'd need two and a half hours (8.3/3.3=2.5). Since the charger will be at best 90% efficient, to get 8.3 kWh of charge into the battery from a 3.3 kW charger you'd need something close to three hours.

Good thing 2013 will cut the home recharge time in half.... to just one hour

SanDust said:

Charging 5 bars in 100 minutes would be quite the trick. Even if you only have 20 kWh usable that would mean you're ending up with 8.3 kWh in the battery in a little more than an hour and a half (5/12 X 20 = 8.333). Can't happen unless you believe that 1.5 X 3.3 = 8.3. Even if the charger was 100% efficient, which it isn't, you'd need two and a half hours (8.3/3.3=2.5). Since the charger will be at best 90% efficient, to get 8.3 kWh of charge into the battery from a 3.3 kW charger you'd need something close to three hours.

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You are overlooking at least three important things, SanDust:

1. The twelve bars do not represent all of the available battery energy. You probably still have about 15% of it left when the last bar disappears. So you can't calculate 5/12 X 20 = 8.333.
2. It seems very unlikely that all bars represent the same fraction of the available energy, again invalidating the above calculation as well as not allowing another term to account for the 15%.
3. Phil (Ingineer) has calculated the input power to the charger carefully, and it is capable of 3.84 kW, not 3.3 kW. The charger is presumably capable of sending 3.3 kW to the battery, so you can forget your 90% adjustment, at least in terms of charger efficiency. There will be some loss at the battery, however. 85% seems to be an accepted overall efficiency with 240v 16A charging, so 3.26 kW into the battery is probably about right.

I could believe that LEAFfan is getting 5.4 to 5.5 kWh into his battery in 100 minutes, and that might well translate to charging from 5+ bars to 10- bars. (9.6 bars - 5.4 bars would be a delta of 4.2 bars.) Put another way, Tony's chart suggests LEAFfan might be charging to 80% from as much as 53%. Even assuming a 21 kWh capacity, 21 * 0.27 = 5.67 kWh. Not far off indeed.

Ray

Tony Williams said.My typical Blink charge is just under 5 hours for 80%, and under 7 hours for 100%.

Hmmm my Blink charger does 100% in 4.5 hours with 10 miles left....My Blink is on the blink also..It either shows the Blink screen or a black screen ,no timer...Blink says there is not software fix :shock:

I was actually going to bring this up in a new thread..How fast does your car fully charge..I remember reading 6-7 hours..