[Kevin Sharpe]

2018 Leaf 40kWh Battery Rapid Charging Issues

A number of owners of the new 40kWh Leaf are reporting very low 'rapid' charge rates (22-24kW) when undertaking a second charge on a road trip. The issue seems to relate to temperature in the passively cooled battery pack.

Here is a good overview of the issue and it might be something to consider if you're planning on using the 40kWh modules in a conversion

 

[AEM]

Hmm couldn’t you just add active air cooling to the battery pack in a conversion to reduce the amount of degradation/overheating during a fast charge? Liquid cooling would be better but more complicated in comparison.

 

[Kevin Sharpe]

Re: 2018 Leaf 40kWh Battery Rapid Charging Issues

Hmm couldn’t you just add active air cooling to the battery pack in a conversion to reduce the amount of degradation/overheating during a fast charge?

The problem with air cooling is it needs a lot of space (cooling fins, air ducts, filters, fans, etc) and that assumes you can get the heat out of the modules (remember the modules used in the 40kWh battery are twice as thick as the 24/30kWh modules).

 

[Tony Bogs]

Some battery chemistries do not perform well at elevated temperatures.

It all comes done to a balance between cost, range, convenience, lifespan and more factors that have to be considered when launching an EV in a certain price range.
Effective thermal management systems for battery packs that degrade severely at elevated temperatures are a major cost factor.

The exact cause of the limited ability to fast-charge is still unknown as far as I know, but this could be bad news for Nissan.

 

[Kevin Sharpe]

More of the same...

 

[Tony Bogs]

And the 30kWh pack is degrading rapidly according to this news item:
https://insideevs.com/nissan-leaf-30-kwh-battery-degrading-more-rapidly-than-24-kwh-pack/

24 kWh packs last a bit longer, but many of the packs of the early Leafs are getting close to their end of life.

 

[PAXtss]

I am curious about the charging parameters, Are these being charged to 100% or less. I have had knowledgeable people tell me that charging to 90% is the best for this type of battery.