Capacity Loss on 2011-2012 LEAFs

[JPWhite]

I'm sorry to hear about the many losses being reported here!

Still able to commute 60 miles on an 80% charge. Hit LBW 1 or 2 times per week at this charge level.

LBW is in the range where I think you might be doing more harm to your battery than you would by charging to 100% just before you leave. Have you considered moving to 100% charging at this point? (Of course, having a 90% option might be best in this case!)

You might be right, I hit the timer override this morning before showering. Might be the best route from this point forward.

LBW occurs at about 24% SOC (58 simulated Gids) for me using the LEAF Battery app. So I should keep it above 25% vs charging to 80%? For some reason I thought the optimal range was 20-80% SOC.

 

[dgpcolorado]

You might be right, I hit the timer override this morning before showering. Might be the best route from this point forward.

LBW occurs at about 24% SOC (58 simulated Gids) for me using the LEAF Battery app. So I should keep it above 25% vs charging to 80%? For some reason I thought the optimal range was 20-80% SOC.

Those LBW numbers seem odd. LBW should come on at the shift from 50 to 49 Gid, which is about 17.5% actual SOC. You might be measuring relative SOC (shows 100% for full even on a degraded battery?). But 58 Gids for LBW suggests that the "simulated" Gids is somewhat off.

If you have a way to measure actual Gids, 20% ought to be about 60 Gid, 40% = 120 Gid, and so forth.

 

[vrwl]

You might be right, I hit the timer override this morning before showering. Might be the best route from this point forward.

LBW occurs at about 24% SOC (58 simulated Gids) for me using the LEAF Battery app. So I should keep it above 25% vs charging to 80%? For some reason I thought the optimal range was 20-80% SOC.

Those LBW numbers seem odd. LBW should come on at the shift from 50 to 49 Gid, which is about 17.5% actual SOC. You might be measuring relative SOC (shows 100% for full even on a degraded battery?). But 58 Gids for LBW suggests that the "simulated" Gids is somewhat off.

If you have a way to measure actual Gids, 20% ought to be about 60 Gid, 40% = 120 Gid, and so forth.

The new version of the Leaf Battery App that Turbo3 is working on now (still in Beta) will have actual GIDs, not simulated GIDs. http://www.mynissanleaf.com/viewtopic.php?f=44&t=12098&start=1600#p309937" onclick="window.open(this.href);return false;

 

[JPWhite]

You might be right, I hit the timer override this morning before showering. Might be the best route from this point forward.

LBW occurs at about 24% SOC (58 simulated Gids) for me using the LEAF Battery app. So I should keep it above 25% vs charging to 80%? For some reason I thought the optimal range was 20-80% SOC.

Those LBW numbers seem odd. LBW should come on at the shift from 50 to 49 Gid, which is about 17.5% actual SOC. You might be measuring relative SOC (shows 100% for full even on a degraded battery?). But 58 Gids for LBW suggests that the "simulated" Gids is somewhat off.

If you have a way to measure actual Gids, 20% ought to be about 60 Gid, 40% = 120 Gid, and so forth.

The new version of the Leaf Battery App that Turbo3 is working on now (still in Beta) will have actual GIDs, not simulated GIDs. http://www.mynissanleaf.com/viewtopic.php?f=44&t=12098&start=1600#p309937" onclick="window.open(this.href);return false;

Yeah I know, I reverted to the regular version this morning due to connectivity issues with the beta. LBW did occur at 50 'true GISDs' yesterday.

 

[TonyWilliams]

The 24kWh capacity battery has warnings at 4kWh stored and 2kWh stored:

LBW = 80 wattHours * 50 Gid = 4kWh
VLB = 80 wattHours * 25 Gid = 2kWh

Please don't confuse that with remaining USEABLE energy of about:

100% = 21kWh with new condition, 70F or warmer battery
LBW = 3.1kWh
VLB = 1.3kWh

 

[cavila1]

This is my first post as I just lost my 1st bar this morning. 7 days past my 2 year purchase anniversary I charge 7 days a week to 100% because of my commute - 50 miles, but mostly freeway, so afraid not to do a full charge. I have 24,000 miles on my LEAF. Park in garage at night and in parking lot in the sun during the day. Haven't updated with latest software upgrade yet.
How does my info get into the wiki chart?
I've seen year-old info to call Nissan to report battery capacity loss, is that still the case?

 

[RegGuheert]

LBW occurs at about 24% SOC (58 simulated Gids) for me using the LEAF Battery app. So I should keep it above 25% vs charging to 80%? For some reason I thought the optimal range was 20-80% SOC.

You're right! I'm making the mistake of equating LBW with about 17% SOC, which is true only for a new LEAF with an undegraded battery. For your level of degradation, it is around 25% SOC, as you say, so that is not so bad.

LBW should come on at the shift from 50 to 49 Gid, which is about 17.5% actual SOC. You might be measuring relative SOC (shows 100% for full even on a degraded battery?).

For a degraded battery, LBW should occur at a higher SOC than 17%.

 

[phxsmiley]

For my Leaf with 8/12 capacity bars (just recently happened), I get 180 Gids on a full charge, LBW happens at 50 Gids.

 

[Stanton]

This is my first post as I just lost my 1st bar this morning. 7 days past my 2 year purchase anniversary I charge 7 days a week to 100% because of my commute - 50 miles, but mostly freeway, so afraid not to do a full charge. I have 24,000 miles on my LEAF. Park in garage at night and in parking lot in the sun during the day. Haven't updated with latest software upgrade yet.
How does my info get into the wiki chart?
I've seen year-old info to call Nissan to report battery capacity loss, is that still the case?

Location? Depending on where you are, that's not too bad given your miles and 100% charging. Now that Nissan has officially issued the battery capacity warranty, I don't see the need in reporting your bar loss to Nissan (I didn't) or the Wiki (it's done it's job).

 

[TomT]

Battery degradation is a vicious cycle. The more capacity you loose, the more often you have to charge and to a greater depth. This, in turn, increases the number of charging cycles and thus the speed of degradation... Nissan clearly did not take this in to account when they stated that they expected degradation to level off with time...

:shock:

For my Leaf with 8/12 capacity bars (just recently happened), I get 180 Gids on a full charge, LBW happens at 50 Gids.

 

[cavila1]

What I didn't say in my earlier post, I'm in San Jose, CA - so while looking at all the capacity losses, and given I've charged 100% - 98% of the time, I guess 1 bar loss after 2 years is considered lucky.

 

[dgpcolorado]

LBW should come on at the shift from 50 to 49 Gid, which is about 17.5% actual SOC. You might be measuring relative SOC (shows 100% for full even on a degraded battery?).

For a degraded battery, LBW should occur at a higher SOC than 17%.

Depends on how one defines the term "State of Charge". I prefer the fixed SOC scale that declines as the battery ages. I presume that the 2013 LEAF uses a relative SOC that shows ~100% when "full", regardless of how much the battery is degraded. To me, that isn't as useful because the fuel scale changes over time.

I find the now "traditional" Gids more useful because, as actual energy units, albeit subject to some measurement error, they give a better indication of range, regardless of battery degradation. Does that make sense?

 

[RegGuheert]

Depends on how one defines the term "State of Charge". I prefer the fixed SOC scale that declines as the battery ages.

Suit yourself. But when trying to decide in what range to most safely operate your LEAF, a fixed SOC is not a good approach, IMO. As the battery degrades, LBW will occur at a higher and higher battery voltage. In fact any fixed number of GIDs will occur at a higher and higher voltage.

As said, if you want to stay within 20% and 80% SOC to maximize battery life, counting GIDs won't help you do this. Only a relative SOC meter which is related to battery voltages will help you do that.

 

[mwalsh]

I find the now "traditional" Gids more useful because, as actual energy units, albeit subject to some measurement error, they give a better indication of range, regardless of battery degradation. Does that make sense?

To me it does. I count each % of Gids as ~1 mile at highway speeds. Except for after I hit LBW (17.4%), where I arbitrarily lop ~4.5 miles off my calculations, giving me ~13 miles remaining range. So 77.4% of gids will give me ~73 miles of range. See?

 

[JPWhite]

To me it does. I count each % of Gids as ~1 mile at highway speeds. Except for after I hit LBW (17.4%), where I arbitrarily lop ~4.5 miles off my calculations, giving me ~13 miles remaining range. So 77.4% of gids will give me ~73 miles of range. See?

I see, but if you use the LEAF battery app you can put in your anticipated miles/kWh, (plug into the app parameters a 'safety margin' of soc) and Bob's your uncle, it tells you your DTE, real time as you drive.

 

[mwalsh]

I see, but if you use the LEAF battery app you can put in your anticipated miles/kWh, (plug into the app parameters a 'safety margin' of soc) and Bob's your uncle, it tells you your DTE, real time as you drive.

But I can't read that without taking my sunglasses off! First world problems, eh?

 

[JPWhite]

I see, but if you use the LEAF battery app you can put in your anticipated miles/kWh, (plug into the app parameters a 'safety margin' of soc) and Bob's your uncle, it tells you your DTE, real time as you drive.

But I can't read that without taking my sunglasses off! First world problems, eh?

It does run on a 7" android tablet. Is that big enough for you grandpa?





I SAID, IS THAT BIG ENOUGH FOR YOU GRANDPA??? (Sorry couldn't resist)

No trouble here with my prescription sunglasses (non polarized)

 

[TonyWilliams]

LBW should come on at the shift from 50 to 49 Gid, which is about 17.5% actual SOC. You might be measuring relative SOC (shows 100% for full even on a degraded battery?).

For a degraded battery, LBW should occur at a higher SOC than 17%.

Depends on how one defines the term "State of Charge". I prefer the fixed SOC scale that declines as the battery ages. I presume that the 2013 LEAF uses a relative SOC that shows ~100% when "full", regardless of how much the battery is degraded. To me, that isn't as useful because the fuel scale changes over time.

I find the now "traditional" Gids more useful because, as actual energy units, albeit subject to some measurement error, they give a better indication of range, regardless of battery degradation. Does that make sense?

Using SOC to determine the LBW and VLB is a bit difficult since those two are specifically indexed to 4kWh and 2kWh respectively, and displayed based on Gid readings of 49 and 24.

Folks, I said this a long time ago... nothing has beat out Gids as the best tool to represent available energy, degradation (at the same temp anyway), fixed energy amounts at LBW and VLB, and a really good guess when the turtle will pop his head out.

 

[RegGuheert]

Folks, I said this a long time ago... nothing has beat out Gids as the best tool to represent available energy, degradation (at the same temp anyway), fixed energy amounts at LBW and VLB, and a really good guess when the turtle will pop his head out.

Yes, you have. Any you are correct. But that does not answer the question which was being discussed.

The point here is that while it may be marginally harmful to drive the car down the LBW when new, it is not as harmful to do this once the battery has degraded by one bar or more, since your SOC is above 19.2% at LBW at the time you lose your first bar. LBW occurs at 24.6% SOC at the time where you lose your fourth bar. Unfortunately, NONE of the displays in the LEAF or on the add-on meters give you this information. The SOC meter in the 2013 does not show battery SOC, but rather only percent of available charge.

So, back to my original point to JPWhite: If you are hitting LBW a couple of times a week, you are taking the SOC below 20% SOC, so it might make sense to charge up beyond 80%. My understanding is that if you need to go out of the target SOC range, it is best to do that on the high side, as long as you don't keep it at the higher charge level long. I will note that the Chevey Volt uses 20% to 85% as their target SOC range.

 

[JPWhite]

So, back to my original point to JPWhite: If you are hitting LBW a couple of times a week, you are taking the SOC below 20% SOC, so it might make sense to charge up beyond 80%. My understanding is that if you need to go out of the target SOC range, it is best to do that on the high side, as long as you don't keep it at the higher charge level long. I will note that the Chevey Volt uses 20% to 85% as their target SOC range.

Thanks for the clarification and explanation.

I did hit LBW 7 minutes from home that day and ended up with an SOC of 19.1%, so I overcooked it a tad. I knew I'd be driving further that day and did charge to 87% prior to departure. I hadn't figured in an extra 2 miles due to missing the turn into the bank that day

I'll err on the side of overcharging vs over discharging in the future.