GCR: Tesla range not degraded by frequent fast-charging, study finds

[GRA]

https://www.greencarreports.com/news/1140640_tesla-range-not-degraded-by-frequent-fast-charging

. . . Recurrent, which produces battery health reports for used EVs, studied fast-charging on over 12,500 Tesla vehicles in the U.S. Cars that were fast-charged at least 90% of the time were compared to cars that were fast-charged less than 10% of the time. Analysts found "no statistically significant difference in range degradation" between the two groups.

Recurrent noted that it is currently conducting similar research for non-Tesla EVs, and said it's still difficult to quantify the effect of frequent fast-charging on batteries over longer periods of time exceeding five or more years.

Further analysis could prove Tesla to be the exception, but for now analysts believe any EV with sufficiently robust thermal, voltage, and battery management systems can protect its battery from damage due to fast-charging.

Earlier studies, looking at models that were more susceptible to heat buildup, found that total miles makes more of a difference than the amount fast-charged. More recently, research has found that, as long as you avoid charging in extreme temperatures and charging all the way to 100%, fast-charging isn't as damaging as previously thought.

Recurrent echoes that advice, telling EV drivers not to fast-charge in extreme heat, to precondition batteries before fast-charging in cold weather, and to avoid fast-charging to a very high state of charge. The company also recommends not fast-charging from a very low state of charge. In both extremes of state of charge, higher battery resistance could cause damage. . . .

Coverage of the same study but with graphs, here: https://insideevs.com/news/683961/fast-charging-vs-slow-charging-study-ev-range-degradation/

 

[knightmb]

I do see the reasoning behind it because in lab studies, rapid charging the Lithium battery over and over does decrease it's capacity over time with temperature and state of charging causing more capacity damage as well, but the lab tests are doing rapid charges over and over more frequently than a typical driver would and from the years of LeafSpy data I've read here on the forum, my Leaf batteries which have hundreds and hundreds of rapid charges over the life of the Leaf were in no more worse condition that a lot of other forum members who had never done rapid charge sessions and took much better care of their batteries than I did. I've long suspected that the rapid charge is probably going to cause more damage when done in more frequent and continued succession versus doing a lot of rapid charges, but spread out more over time. Just my thinking though, I'll wait for some other scientist to put that data together for a better report in the future.

 

[cwerdna]

Haven't had time to look at the OP but apparently, 75 and 90 kWh Tesla packs get "nerfed" after too much Supercharging: https://teslamotorsclub.com/tmc/threads/90-and-75-battery-packs-getting-nerfed-early.152322/.

2016 S75D from service center visit:
Confirmed low DC charging speeds in vehicle logs. Investigated cause and confirmed the battery management system has slowed the maximum charge speed due to high repeated use of DC charging.
This is a normal function of the battery to avoid loss of range caused by high DC charge use.
The DC charge limiting is set to start at 2625 kWh and reaches maximum derating at 13125 kWh. Your vehicle is at 15635 kWh as of the end of charge on the 17th.
The charge speed will not reduce further but continued DC charging will not cause a slow loss of range. This is a designed function to maintain the longest battery life possible. There is no defect.

 

[DougWantsALeaf]

Knightmb, I think your analysis is sound.

The only gen2 Leafs which have really been challenged battery wise are those in livery/hard rideshare service.

 

[WetEV]

I do see the reasoning behind it because in lab studies, rapid charging the Lithium battery over and over does decrease it's capacity over time with temperature and state of charging causing more capacity damage as well, but the lab tests are doing rapid charges over and over more frequently

I wonder about average, minimum and peak charge levels, temperatures and lots of other complications. The original report is at:

https://www.recurrentauto.com/research/impacts-of-fast-charging

I'd still expect faster capacity loss with DCQC, but not lots faster.

 

[charliecasillas]

I do see the reasoning behind it because in lab studies, rapid charging the Lithium battery over and over does decrease it's capacity over time with temperature and state of charging causing more capacity damage as well, but the lab tests are doing rapid charges over and over more frequently

I wonder about average, minimum and peak charge levels, temperatures and lots of other complications. The original report is at:

https://www.recurrentauto.com/research/impacts-of-fast-charginggeometry dash subzero

I'd still expect faster capacity loss with DCQC, but not lots faster.

I have a wonder about EV batteries. I'm new and I cannot understand well. Can you explain more about the software and hardware protections in EV batteries?