Full to Empty, maybe a stupid question

[Paul73]

I've had 2 years waiting for the Model 3 to read about batteries.

Charging very high causes a "rollover" failure, a sudden failure after fewer cycles, even if the degradation has been slow so far (the parasitic reactions cause contamination which gradually builds up, eventually blocking the electrode surface area and causing lithium plating and sudden collapse of capacity).

Every 0.1 V reduction in charge voltage roughly doubles the cycle life? Until the perfect battery exists I plan if I can to "hibernate" with a daily topup to 3.8 V per cell (approx 60% with Panasonic) for short trips, to try to preserve the capacity for 20 years.
Charging to a set voltage means error build-up of the estimated state of charge due to repeated shallow depth of discharge shouldn't matter.

Apparently there's a step increase in parasitic reactions above 60%, but not so bad as long as not left at a high state of charge for a long time? (even charging to 80% is much better than to 90%)

Small topups every 100 miles on long trips when possible e.g. 80%/40% for a shallow approx 40% depth of discharge, and usually charging at home with <=7 kW (C/10) should help the battery last.

With my phone I usually try to stay between 45% and 75%, and never below 20% (low state of charge increases internal resistance?)
(I set Accubattery on android to notify above 70%).

 

[Paul73]

I've had 2 years waiting for the Model 3 to read about batteries.

Charging very high causes a "rollover" failure, a sudden failure after fewer cycles, even if the degradation has been slow so far (the parasitic reactions cause contamination which gradually builds up, eventually blocking the electrode surface area and causing lithium plating and sudden collapse of capacity).

Every 0.1 V reduction in charge voltage roughly doubles the cycle life? Until the perfect battery exists I plan if I can to "hibernate" with a daily topup to 3.8 V per cell (approx 60% with Panasonic) for short trips, to try to preserve the capacity for 20 years.
Charging to a set voltage means error build-up of the estimated state of charge due to repeated shallow depth of discharge shouldn't matter.

Apparently there's a step increase in parasitic reactions above 60%, but not so bad as long as not left at a high state of charge for a long time? (even charging to 80% is much better than to 90%)

Small topups every 100 miles on long trips when possible e.g. 80%/40% for a shallow approx 40% depth of discharge, and usually charging at home with <=7 kW (C/10) should help the battery last.

With my phone I usually try to stay between 45% and 75%, and never below 20% (low state of charge increases internal resistance?)
(I set Accubattery on android to notify above 70%).

 

[animorph]

You'll have to wait significantly longer to charge from 40% to 80% than 10% to 50% during long trips. Not a total disaster, but not what I would want to do. It will be interesting to see the effects of these measures in 5/10/20 years and find out if it was worth the trouble.

 

[DJP31]

Small topups every 100 miles on long trips when possible e.g. 80%/40% for a shallow approx 40% depth of discharge, and usually charging at home with <=7 kW (C/10) should help the battery last.

The galactic miles some cars in the US and Scandinavia have racked up, with little appreciable range degradation, is enough for me not to worry about this.

 

[arg]

Note that the lecture linked above is over 5 years old, reporting research prior to that date, and the lecturer has been working for Tesla to improve their cells. So you might imagine that Tesla's cells and battery management algorithms have taken those factors into account.