[MagickPanda]

Hello there, I am an owner of 2 eletric vehicle, I kinda want to start a blog about electric vehicle/battery information. Just curious what is the major factor that affects battery capacity permanently, over time drop or over cycle drop?

According to the web cycling is the major issue, but from my real-life usage eperience the capacity/range per 100% SOC doesn't differ between EV with 30k KM and 130k KM, hence the question.

Thanks.

 

[EdH]

What cars do you have?

 

[MagickPanda]

BYD e5 2016(47.5kwh LFP) & BAIC ex5 2019(61.8kwh NMC)
Both are exclusive available in China though, since only very few Chinese EV's are available worldwide.-_-

This is BYD e5 2016:

This is BAIC ex5 2019:

What cars do you have?

 

[Rei]

There are all sorts of ways to calculate range and SoC so it's really hard to know without details of how those cars work.

 

[MagickPanda]

Most battery pack vendors do have a backend cloud server to store and moniter battery voltage in real-time.
Sadly most vendors don't make such information available to end users, though some cars do have a 'current voltage' to tell the sum of individual cell packs voltage.

There are all sorts of ways to calculate range and SoC so it's really hard to know without details of how those cars work.

 

[ScottC]

Instantaneous voltage reading on most battery types, but especially lipo are useless in determining state of health. Even a very badly degraded cell will show 4.2V for some hours after a full charge. However, when you discharge, you may see only 50% of rated capacity before voltage falls below 3V.

 

[Rei]

You really need something like LeafSpy to get enough information to make your own judgement.

 

[MagickPanda]

Thanks for the info, though I doubt LeafSpy will work on non-nissan EV cars.

Hmmm so there is no easy way to measure the estimated cell capacity drop?

Instantaneous voltage reading on most battery types, but especially lipo are useless in determining state of health. Even a very badly degraded cell will show 4.2V for some hours after a full charge. However, when you discharge, you may see only 50% of rated capacity before voltage falls below 3V.