Battery based electric vehicles of today and tomorrow.

[Gale Hawkins]

(re: faster battery charge rate increases wear)

But “back then” they were talking about 0.5C, 1.0C, and rates up to 5C. Where C = battery amp-hour capacity / hour.

1C is charging a 1Ah battery at 1A.

My 85 kWh Tesla on 9.6 kW at home is 0.113C, trickle charging by old time rules.

115 kW at Superchargers is still only 1.35C which is only held a few minutes. Quickly drops to 70 kW and keeps falling. Even “many years ago” 1C was considered to be a conservative fast charge rate so long as cell warming was monitored. Today most all battery packs (cellphone, power tools, computer, etc) contain a thermistor for the charger to monitor warming.

Today's concern is dendrite growth in lithium ion batteries.

 

[Grumpycat]

Today's concern is dendrite growth in lithium ion batteries.

So you are saying 0 growth at 0 charge but more the faster one charges? I don’t think so. More likely there is a range of minimal wear. And as with sulfation for wet lead acid, an electronic conditioning which mostly reverses.

Is different but the point remains, a NiMH cell can not be trickle charged at 0.1C the way NiCAD or wet lead-acid can. The NiMH deteriorates. The proscribed charge technique by the cell manufacturer is 1C until a specified voltage is reached for the cell temperature. Thereafter pulse a 1C charge to “trickle”, at perhaps 5% to 10% duty cycle.

Self anointed pundits have been proven wrong in claiming Moore’s Law was going to apply to EV battery capacity. They still shout from the highest tower every time a “breakthrough” supposedly occurs. I think the public has wised.

Such pundits were proclaiming “EVs will never be viable until we have a battery the size of a gas tank with similar range” And not only that but forthcoming breakthroughs would make that come true in only a few years! That “Musk and Tesla are idiots for building a 1400 pound battery plus 3600 pound car to carry it 265 miles because it will be outdated and outclassed in only a few years.”

“Everybody knew” consumers only “needed” 80 mile EVs like the Nissan LEAF and BMW i3.

Tesla has disappointed the pundits for not doubling range every 18 months. Tesla has had an excellent range for 10 years. Tesla is focusing on manufacturing, materials, and battery life. Not so much the sexy topic of range which simple minded influencers understand.

All other manufacturers are expecting someone else to invent batteries for them. Expecting someone else to build charging stations for them. TSLA is grossly overvalued but no one else seems to have a clue as to what is needed.

 

[Gale Hawkins]

Heat can eat most any form of electronics. Tesla side steps the denritic growth problem because they use active battery temperature management.

The Nissan Leaf as of today still have zero active battery temperature management. It seems as of the 2018 model both of those current lithium ion batteries chemistry does much better and denritic really growth is not problematic but still I would not fast charge one on DC.

My 2016 30 kWh failed after 25K miles. The 2020 40 kWh replacement State Of Battery is dropping more like 2% a year with the 12 volt connected and Zero % if parked with 12 volt battery disconnected so I put a blade disconnect switch on the battery.

I'm going LFP if that is an option next time because they do not have the dendritic issue.

 

[Gale Hawkins]

This could impact cheap China EVs and tractors and other steel products that we depend on parts-wise etc.

 

[airbiscuit]

Heat can eat most any form of electronics. Tesla side steps the denritic growth problem because they use active battery temperature management.

The Nissan Leaf as of today still have zero active battery temperature management. It seems as of the 2018 model both of those current lithium ion batteries chemistry does much better and denritic really growth is not problematic but still I would not fast charge one on DC.

My 2016 30 kWh failed after 25K miles. The 2020 40 kWh replacement State Of Battery is dropping more like 2% a year with the 12 volt connected and Zero % if parked with 12 volt battery disconnected so I put a blade disconnect switch on the battery.

I'm going LFP if that is an option next time because they do not have the dendritic issue.

What function does the 12v battery serve, and how does disconnecting it when parked improve longevity?

 

[Gale Hawkins]

What function does the 12v battery serve, and how does disconnecting it when parked improve longevity?an

12v function same as on an ICEV. As to why it eats into SOH I don't know and I only found out because it has been parked for 14 months. The shop that was to do the dash removal to install passenger air bag last month didn't get to it.

Maybe it is spooky action at a distance that Albert Einstein talked about.

 

[airbiscuit]

had to look up spooky action at a distance. Hard to wrap your head around.

 

[Gale Hawkins]

had to look up spooky action at a distance. Hard to wrap your head around.

Thanks to the confusion and a craziness of the past 2 years I finally got a grip on Quantum mechanics to some degree.

 

[Hay Dude]

This could impact cheap China EVs and tractors and other steel products that we depend on parts-wise etc.

Interesting article. Just goes to show China has massive problems, too.

 

[Gale Hawkins]

This covers some GM business changes magement wise.