Traction Battery Questions

Does anyone here have data showing that multiple full charges does a better job of cell balancing than a single full charge? I have been charging my 2013 to 80% almost all of the time, and just fully charge a few times per year. I wonder if there is any data to show that my cells could be getting badly out of balance, or if one full charge should restore the pack to balance.

Does anyone here have data showing that charging to 80% is better on the battery than full charge? It has been claimed that batteries lose capacity faster if resting with a full charge, but with the Leaf being in production for 5 years, I've yet to see any data quantifying the magnitude of the effect.

Thank you.

Bob

If the battery is going to be just sitting, it is best to have the charge level between 30% and 80%. Letting the battery sit at 100% charge for extended periods of time, especially in high heat, is very detrimental to the life expectancy. If the car is driven every day, there is nothing wrong with charging to 100% during the night, as long as the initial morning drive gets the charge level down around 80% (or lower).

If charging to 80% provides enough range for the daily driving needs, continue doing that. I would recommend a charge to 100% every two weeks to keep the cells balanced (followed by a drive to bring it down around 80%). LeafSpy can be used to get a reading on the health of the battery, and to see how well balanced the cells are.

Since the option to charge to 80% was removed for the 2014 and newer models, I doubt that their has been sufficient data gathered to show it extends battery life. The chemistry changes in the batteries (April 2013, for 2015 model year, possibly for 30kwh and newer packs) would also considerably skew the data gathered.

Answer is very short.
Yes, 80% charge will prolong battery life SLIGHTLY if it is not counteracted with deep discharge (below 20%).
This is more noticeable with hotter batteries (climate).

Yes, battery might get really unbalanced if charged to 80% and not discharged below low battery warning.
My battery capacity calculation drifted away for at least 5% after few months with no extreme charge states.
I ran out last 10% of charge with half the distance promised with very light foot
One heavily drifted cell is enough to bring the Leaf to the knees.

One full cycle will not balance perfectly. 3 full cycles is usually enough with at least 5 temperature bars.

I do at least one 100% charge every month and one deep discharge. No problems noticed.

Bob said:

Does anyone here have data showing that multiple full charges does a better job of cell balancing than a single full charge? I have been charging my 2013 to 80% almost all of the time, and just fully charge a few times per year. I wonder if there is any data to show that my cells could be getting badly out of balance, or if one full charge should restore the pack to balance.

Click to expand...

You can see your battery balance in Leaf Spy app for IOS or Android. Very easy to check, and really not an issue for 99% of the cars on the road.

You'd have to do something very very unusual to hit balance issues.

You live far enough north that heat isn't an issue so just drive it and don't leave it charged to 100% for more than a few hours at a time and don't let it get below 20% if you can help it and all is good.