Preventing battery degradation

[jeffand]

From what I understand is that older Leafs have the option to charge to 100% of the batteries full capacity. I also think Tesla model S also has this ability to. Most other EV manufactures don't allow 100% charging of the battery, because customers will likely abuse the battery. This maybe why Nissan took the option away.

 

[michael]

That's not exactly right.

The older Leafs had the option to charge to either 100% or 80% of whatever portion of the "true" capacity. In no case did they fully charge or fully deplete the battery. In the same way, when you charge your FFE to what is displayed at 100%, it's really about 90%; and when you fully discharge it to 0%, it's really about 8%. (This is based on OBD scanner displays)

By contrast, at least according to this post

http://www.mynissanleaf.com/viewtopic.php?f=8&t=8266

100% for a Leaf is really 95% SOC, and 0% is really 2%.


Nissan did NOT take away the option to go to 100% (of the available range). What they took away is the 80% option with the 2014 model. The reason they did that was that the EPA required them to report range based on the average of the 80% and 100% ranges. By turning off the 80% option, Nissan was able to claim an imaginary 10% increase in range.


If you sense that I have a low regard for the design of the Leaf, and an amazement about the number of people who select it over the FFE, you are right!

 

[studio460]

Depending on where you work, I might be able to drop by and plug in the OBD scanner and then you won't need to guess about the battery temp.

I take 405 N to 118 W. You anywhere nearby? Do you want to give this a try?

This afternoon I arrived in the valley at 4. Outside temp was 99 F so the "plug in it's hot" message popped up, but battery temp was will 80. I parked in direct sun for 2 1/2 hours on hot asphalt, and when I returned the battery temp had risen only to 84. Since the battery temp never approached 98, plugging in would have made no difference.

Sorry, I missed your post somehow. Sure, thanks! I work near the 134 and Buena Vista in Burbank. But, from reading your latest report, it doesn't seem like an issue.

 

[studio460]

studio460 - if you go into work midday or later, I don't think you have anything to worry about since your TMS would have been running on the drive to work.

Thanks!

 

[studio460]

Based on the best information I can find, being hot and at high state of charge is the MOST harmful thing to a battery. The charging and discharging process are not the problem. The end result of charging (i.e. being charged and hot) is bad . . . Based on his information, I charge only to the extent necessary, and and close as practical to departure time (not upon arrival). Studio 460....my advice is charge to maybe 70% (or whatever is the minimum that will guarantee your arrival with comfortable margin) at both ends of your commute. Do not needlessly fully charge.

Thanks again, Michael! That sounds like a good strategy. Hopefully, I'll finally get around to buying my new FFE this weekend (I just bought a Level 2 charger).