Not sure if this is normal?

Hello everyone! I'm new to the forum. I'm a recent 2015 Leaf SV owner. 50,000 miles/ 9bars. Yesterday, I arrived home with 7% left on my battery. I put it on L1 charging overnight, along with a Kill-A-Watt unit to observe my findings. This morning the car reported 100% full, but the kill-a-watt showed only 14.4kWh was put in. I'm certain I have the 28kWh battery, but could I be wrong? Could this batter really have half capacity left? Am I missing something?
thanks.
Tyler

Welcome. The batteries used from 2011 until mid 2016 are all 24kwh, not 28kwh. Of this, several KWH are reserved. So with 3 capacity bars gone (the first one is worth 15%, the others about 6% each), the amount of charge added seems at least ballpark correct.

A 2015 Leaf has a nominal 24kWh battery that IIRC is actually about 22kWh usable capacity when new. Since you have 9 bars, your capacity is very roughly 70% of new so your battery actually is about 15 kWh capacity. 9 bars covers approximately 65-72% of new capacity as the first bar is 15% +/-. The charging isn't 100% efficient so take that into account also.

Finally, there is actually some 'hidden' range below 0% SOC which is hard to quantify so there may be a slight adjustment there.

Hopefully the range will be sufficient for your needs but I would trust the meter more than anything the car reports.

The bottom line, of course, is how many miles you can drive on a full charge and whether or not the car meets your needs. Almost everyone improves their efficiency after driving an EV for a while as they adapt to an EV. If you live in a climate where it gets cold, be ready for a drop in range due to the fact that any cabin heat must be generated from the battery and the fact that all batteries lose capacity and efficiency when cold.

Welcome to the world of EV's ! I think you will like it.

For reference, https://usa.nissannews.com/en-US/releases/release-513847a8aeeb48d480a52a8fbdcdbd93-us-2015-nissan-leaf-press-kit is the '15 Leaf press kit.

You probably had at least 5 kWh of useable energy left at 7% SOC (on dash display) so the 14.4 kWh charging energy is reasonable. L1 charging is less efficient so the 14.4 kWh input probably yielded about 12 kWh into the battery. Useable capacity of 17 kWh is commensurate with 9 capacity bars.

That would be 9 "full" bars, of course. If the car is about to lose the ninth bar, then capacity would be much closer to 8 bars.

Thank you to everyone! And yes, I knew it was 24kWh battery, not sure why I typed 28. At any rate, it sounds like nothing out of the ordinary then. I'll continue measure what I'm putting in.
On that note, I got all kinds of notifications as my battery was going down, as I was driving home, starting at 15% i think. Even the "miles left" indicator went away, and just displayed a flashing flat line. As I said, I was home by 7%, but what exactly happens when it gets critically low? I imagine the last ditch effort is your forced to pull over and park before the motor shuts down? And is it generally good practice to periodically run down your capacity to 5 or 10%? Or is this considered a big no-no? In the LiFePO4 battery world, I will deplete my off-grid DIY banks down to about 3-5% once about every 6 months or so. They live and cycle mostly in the 25%-95% SOC.

thanks again for all the great info!

Tyler

You can run the battery down that low once in a while, but it's important to make sure that you plug it in to charge as soon as you get home. It's better to stay above 20%, or at least above 10% charge.

The LEAF's pack chemistry is very different from LFP packs. From everything I have read, a high DoD isn't good for the LEAF's pack. Use it if you really need the range, but don't make a habit of running it down, thinking that will increase its longevity - it won't.

What you described, when the SOC gets low, is normal. After the dashes appear, there's still another 1 kWh or so remaining. When the pack SOC gets really low, a little turtle icon will appear on the dash, along with this message:



Once the turtle appears, shutdown follows quickly thereafter.

On my 2015 SL the first low battery warning came at 6% SOC on the dash when remaining miles started flashing at 49 Gids on Leaf Spy. The second warning (very low battery) came at 2% SOC when the remaining miles went to "---" at 24 Gids on Leaf Spy. Motor power limited (Turtle Mode) came between 8 and 5 Gids on Leaf Spy with shutdown very soon after, usually at 4 Gids on Leaf Spy. There was typically 7 miles in suburban driving between low battery warning and very low battery warning and another 7 miles after very low battery warning before turtle mode.

FWIW, I often discharge to very low battery warning before charging fully. I believe the battery deterioration in all three of my cars was (is) no worse than others experience in the hot desert climate in which I live. I also ran full discharge/charge tests every month to track battery capacity of the 2011 and 2015 using a revenue accuracy meter ahead of the L2 EVSE. I run full discharge/charge tests every 3 months with the 2019 because longer charging times require planning to run tests on weekends. I post my discharge/charge test results every 3 months in the 62 kWh battery thread. The next test will be this weekend.

Interesting. I guess I'll have to get LeafSpy. I'm in Vegas, so, like Phx, the heat is a concern of mine. Every 3 months doing a full discharge/recharge to track capacity isn't a bad idea. Or every 6 months.. I don't have a meter to track a L2 charging, just the standard kill-a-watt 120V unit. Now, I've been L1 charging 98% of the time, (overnight fits my schedule best) but I've been reading that L2 charging is more efficient? Any truth to that? My L2 EVSE is a Lectron 16A version, and the Nissan one charges at 11.5A. I'm happy to charge at a higher rate, but i thought a slower rate is better for the batteries, allows for better absorption. What's best practices here?

Tyler

Both are considered ok. You don't really want to do a full discharge in that Hot climate, IMO. Try to keep the car in the 25% - 80% range as much as possible.

TylerNV said:

Interesting. I guess I'll have to get LeafSpy. I'm in Vegas, so, like Phx, the heat is a concern of mine. Every 3 months doing a full discharge/recharge to track capacity isn't a bad idea. Or every 6 months.. I don't have a meter to track a L2 charging, just the standard kill-a-watt 120V unit. Now, I've been L1 charging 98% of the time, (overnight fits my schedule best) but I've been reading that L2 charging is more efficient? Any truth to that? My L2 EVSE is a Lectron 16A version, and the Nissan one charges at 11.5A. I'm happy to charge at a higher rate, but i thought a slower rate is better for the batteries, allows for better absorption. What's best practices here?

Click to expand...

If L2 and L1 are the same power
You will heat up the battery less with the L2, and use less energy. This follows from the fact that higher voltage means lower current and current is proportional to loss.

In your case the L1 is lower current and lower voltage so you end up with a trade-off: the L2 saves energy but heats up the battery a wee bit more.

Use L2

SageBrush said:

TylerNV said:

Interesting. I guess I'll have to get LeafSpy. I'm in Vegas, so, like Phx, the heat is a concern of mine. Every 3 months doing a full discharge/recharge to track capacity isn't a bad idea. Or every 6 months.. I don't have a meter to track a L2 charging, just the standard kill-a-watt 120V unit. Now, I've been L1 charging 98% of the time, (overnight fits my schedule best) but I've been reading that L2 charging is more efficient? Any truth to that? My L2 EVSE is a Lectron 16A version, and the Nissan one charges at 11.5A. I'm happy to charge at a higher rate, but i thought a slower rate is better for the batteries, allows for better absorption. What's best practices here?

Click to expand...

If L2 and L1 are the same power
You will heat up the battery less with the L2, and use less energy. This follows from the fact that higher voltage means lower current and current is proportional to loss.

In your case the L1 is lower current and lower voltage so you end up with a trade-off: the L2 saves energy but heats up the battery a wee bit more.

Use L2

Click to expand...

I was afraid of that answer..lol.. Now I've got to get a split phase 120/240 inverter! All my L1 charging is being done from my off grid solar setup, and unfortunately both my inverters are 110/120 only. I have a 240V "dryer" receptacle in my garage, and I'll use that every once in awhile for my L2, but I really like the idea of charging off grid for free!

hmm.
Perhaps all you need is a transformer. You would end up with a lower current so your charging time would stay the same but you would have lower losses and less battery heating.

I'll be interested to hear what others have to say.

As I understand it, a transformer has to have AC as the input, so he'd have to use it on the AC produced by his inverter(s), while an inverter can use the DC that I assume is produced by his panels - unless he has micro inverters, which doesn't appear to me to be the case.

L2 is usually more efficient than L1 since the charging overhead (coolant pumps, etc) that run while charging is fixed. As L2 usually charges faster than L1 the overhead as a percentage of total power used is less when the charge is completed in less time.

If your power level is fixed then I don't think you will see much difference since the charge rate (and time) will be the same regardless of the voltage.

SageBrush said:

If L2 and L1 are the same power
You will heat up the battery less with the L2, and use less energy. This follows from the fact that higher voltage means lower current and current is proportional to loss.

Click to expand...

Err, the extra losses will be suffered in the On Board Charger and the AC cables, not the battery. At the output of the charger , the voltage is dictated by the battery's SoC, regardless of the AC voltage used to make that voltage.

So if charging is more convenient at L1, and you don't mind a little inefficiency (marginal solar power is essentially free, right?), then there is no reason not to charge at L1. A 60 Hz transformer will just be expensive, heavy and awkward, and will have its own losses, without affecting the battery (other than that it will get a little less charge per hour due to the extra losses).

coulomb said:

SageBrush said:

If L2 and L1 are the same power
You will heat up the battery less with the L2, and use less energy. This follows from the fact that higher voltage means lower current and current is proportional to loss.

Click to expand...

the extra losses will be suffered in the On Board Charger and the AC cables, not the battery.

Click to expand...

Yep, for the most part. I decided to try and keep my post focused on the end results and not complicate the explanation. It remains true that the higher current will deposit more heat in the battery.

That's true but the battery current is based on the input power and it will be identical whether that input power is supplied at 120V or 240V.