Battery management

[GadgetGav]

Do we need to take care to cycle the battery charge to get maximum range?
The reason I ask is that I only recently found out how to change the battery charge percentage and the advice on that screen is to vary it from the default of 100% so I put it at 90%. It didn't seem to make much difference to my estimated range when I unplug in the morning and I didn't really think much more about it.
Yesterday I used the car more than normal, running to the dentist as well as my usual commute and then a 43 mile round trip in the evening. When I got home the range estimate was down to 15 miles and I plugged in to charge as normal.
This morning the range estimate was 75 miles whereas it's usually been 68 or 69. Maybe it was slightly warmer this morning (although I think it was still around freezing) or could it have been that I ran it down a lot the previous cycle?

I'm thinking I'll either start varying the percentage setting more often or not topping off every day. The only downside to that is if I need to make an unexpected trip (like my trip to the dentist was) I might get caught out.

Has anyone noticed a difference between topping off and running the charge way down?

 

[LAeGolf]

From what I've read, the car is happiest between 20% and 80% - if possible keep the range between those two.

As for the miles "guesstimate" on the display, it re-calculates that based how you drive. Let's say you drive 60 miles one day in the city only, then charge to 80%, it will show 82 miles the next morning (for example)

Then you drive 60 miles all highway the following day, charge to 80%, it will show 75 miles then.

 

[GadgetGav]

From what I've read, the car is happiest between 20% and 80% - if possible keep the range between those two.

As for the miles "guesstimate" on the display, it re-calculates that based how you drive. Let's say you drive 60 miles one day in the city only, then charge to 80%, it will show 82 miles the next morning (for example)

Then you drive 60 miles all highway the following day, charge to 80%, it will show 75 miles then.

So you're saying my hypermiling trip in Eco mode has messed up my estimates for a while I managed to do 22 miles and only knock 4 miles off the estimated range!

 

[ellipsoid]

From what I've read, the car is happiest between 20% and 80% - if possible keep the range between those two.

I've also heard this in a bunch of places -- anyone have a definitive citation for this? Anything from VW?

I'm charging at 110V currently (hah!) and want to know how often I should charge, both to maintain my available range and to keep the batteries happy. I travel about 15-20 miles per day, total.

 

[RonDawg]

Anectodally, over at MyNissanLeaf it's believed that frequent but shallow discharge/charge cycles are more beneficial for the battery that fewer but deeper cycles.

In the case of my own Leaf, I still have all 12 capacity bars after 31 months and 25k miles. In my area I should have lost a bar by now. I believe my better-than-expected degradation has to do with the fact that besides keeping my car garaged both at home and at work I am charging everyday but only for a few kWH each time, rather than waiting for the battery to be nearly depleted.

For the first 3 model years, Nissan did put an 80% "Long Life Mode" setting, but took it out for MY 2014. The official reason was that Nissan said it wasn't necessarily beneficial, but many of us believe it's to get increased total range estimates from the EPA (who were reporting an average of the 80% and 100% charge settings). 2011-2013 was 75 miles, 2014 and later is 83 miles even though the battery capacity is the same. Further fueling that belief is the fact that new Leafs sold outside of North America still have this setting.

One thing you do want to avoid is leaving the car at 100% for long periods at a time. Leaving the car between 20% and 80% is recommended for long term storage (such as going away on a business trip or vacation).

 

[Electricbowtie]

Anyone notice the new website and app removed the ability to throttle back the charge max to only 10% increments? I would rather charge to 95% to 98% because some days need that extra range but want to protect the battery from 100% SOC degradation.

 

[GetOffYourGas]

Anyone notice the new website and app removed the ability to throttle back the charge max to only 10% increments? I would rather charge to 95% to 98% because some days need that extra range but want to protect the battery from 100% SOC degradation.

If it makes you feel any better, 100% isn't truly 100% - all EVs keep a buffer at the top and bottom of the battery. Moreover, if you car charge the car so that it's ready right when you need it, you will have very little time at 100%. And time at 100% is what you should be limiting. High SoC is not a kill switch for battery life, but rather increases the rate of degradation. So consider charging the car to 90%, and then topping off right before you leave (if you have the luxury of knowing).

 

[GetOffYourGas]

Here is a thorough reference with more than you ever wanted to know about batteries:

http://batteryuniversity.com/

Key things that kill batteries:
1) Heat!
2) Charge/Discharge rates (creates heat!)
3) High/Low states of charge
4) Charge/Discharge cycles
5) Time

 

[vetaldj]

I have some observation myself.

I usually keep at least "20 miles left" before charging. Average after full recharge was always 80-90 miles left. Very rarely I saw more then 100, it was not more then 105 miles.

Last week I was having bad luck with chargers and I did stuck in the middle of Costa Mesa with 2 miles left (8 physical miles left to home). First charge after that did add whooping 118 miles, all following - from 110 to 115 miles.

Not sure if this is somehow related but I definitely don't want to repeat this thing, running on few miles left doesn't worth it ... Anybody had this happen? Doesn't it useful sometime to flush it out completely to refresh or something?

 

[miimura]

I have some observation myself.

I usually keep at least "20 miles left" before charging. Average after full recharge was always 80-90 miles left. Very rarely I saw more then 100, it was not more then 105 miles.

Last week I was having bad luck with chargers and I did stuck in the middle of Costa Mesa with 2 miles left (8 physical miles left to home). First charge after that did add whooping 118 miles, all following - from 110 to 115 miles.

Not sure if this is somehow related but I definitely don't want to repeat this thing, running on few miles left doesn't worth it ... Anybody had this happen? Doesn't it useful sometime to flush it out completely to refresh or something?

I would guess that when you were down at the bottom of the battery you were driving much more conservatively and the car forced you down to Eco+ as well. That results in a better mi/kWh figure. That alone will make the gauge show more miles per tank after the next full charge. This is why it's called a Guess-O-Meter (GOM). The car is just guessing how far the car will be able to go based on past performance and current settings. It's really just a SWAG (silly wild assed guess). If you consistently drive like a granny, you will consistently see that number over 100 or 105 miles.

 

[GadgetGav]

Yes, I've found that one out-of-character drive can throw off the range estimate for the next time. It must average over a short timeframe - which is probably necessary for it to avoid saying you've got plenty left when you're actually out. I've noticed turning Max AC on cuts 10 miles from my range estimate immediately and if I turn it off a mile or two later, I get that back.

 

[garypen]

They will have to pry my Max AC from my cold comfortable fingers!