Battery Degradation- I know it’s the Telegraph, but….

The underlying research has been published before and is regularly updated. The takeaways are not a surprise:
  • actively cooled batteries are the best
  • regular DC charging is not good
  • cars with decent buffers to start with perform better
  • apart from the passively cooled Nissans, the rate of degredation isn't an issue, particularly not for the first owners
What's not included is the effect of regular deep discharges. If, say, you use 45% of the battery capacity per day the battery will last longer recharged daily from say 35-80% than every second day from 10-100%.
 
No two car designs are alike though, everything is built to a price.
 
BugEyed said:
The underlying research has been published before and is regularly updated. The takeaways are not a surprise:
  • actively cooled batteries are the best
  • regular DC charging is not good
  • cars with decent buffers to start with perform better
  • apart from the passively cooled Nissans, the rate of degredation isn't an issue, particularly not for the first owners
What's not included is the effect of regular deep discharges. If, say, you use 45% of the battery capacity per day the battery will last longer recharged daily from say 35-80% than every second day from 10-100%.
Click to expand...
I have done 14k miles in 10 months with mostly DC rapid charging, SOH is still 100%.
 
The early model LEAF gets somewhat criticised yet real world experience showed that it far exceeded expectations over time. It was the LEAF that demonstrated that battery life would be considerably better than the 5 years or so that was the basis for battery lease rather than outright ownership. Renault for one ONLY offered lease as the option for the battery.

When I 1st looked at going electric the industry was expecting typically 5 years for the battery. I wanted to work out how much I would have to put aside per month to buy a battery after 5 years as an alternative to refuelling an ICE car each month. I found it nigh on impossible to get a price for any vehicles battery that I could then "chop up" into 60 monthly payments. I found that lease costs were on a par with the amount of fuel I was buying so there would have been no real saving switching to electric.

The Nissan experience particularly in Norway was that a) battery life as a whole was better than expected and b) cell pack replacement was much more viable as a method of extending battery usage than initially had been considered.
 
I have a 2017 30 kw first gen Leaf Tekna with 35k miles, still at 100% (Bought used 2 years ago for £13,000). Car looks are.... Interesting, but its a pocket rocket the size of a VW Golf and I really enjoy driving it (does about 120 miles in summer, 100 miles winter). I only charge at home overnight on Octopus go, its saved me a fortune.
The MG LR EV is to replace our diesel Verso, Im not parting with the Leaf :)
 
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My Wife's 8 year old LEAF is at 82% of its original capacity, down from 84% when she bought it 5 years and 48,000 miles ago. The early high degredation we put down to the original owner keeping it at 100% charge all of the time. The range of 65 miles on a cold wet winter's night is "sufficient" although she does take the MG5 LR sometimes for larger loads and distances.
 
BugEyed said:
My Wife's 8 year old LEAF is at 82% of its original capacity, down from 84% when she bought it 5 years and 48,000 miles ago. The early high degredation we put down to the original owner keeping it at 100% charge all of the time. The range of 65 miles on a cold wet winter's night is "sufficient" although she does take the MG5 LR sometimes for larger loads and distances.
Click to expand...

We had a 24kwH 2012 Leaf for 2 years between 2016 and 2018 and it really suffered with degradation. It lost 2 'bars' while we had it, not sure how that relates to SOH.

Unfortunately there wasnt really an option not to charge to 100% as the battery was so small and we therefore wouldn't get the range required. I'm pretty sure this was true for many owners.

Fortunately, with considerably larger packs there is more scope to limit SOC to maintain battery health.
 
To clarify, charging to 100% is not a "bad thing", but leaving the car at 100% for an extended period is.
In terms of range and mileage it depends on how you use it. My Wife manages around 12,000 miles a year but spread over most days, so typically 40 miles per day. This avoids both needing to charge to 100% or deeply discharging the battery. But her car would not suit someone only using a car for 100 mile trips at the weekend where a bigger battery (say 35-40 kWh) is needed. Whether I justify the 60kWh of the MG5 LR with a similar normal daily mileage and only monthly jaunts over 200 miles is open to debate.
 
I drive about 100 miles every 7 days I then charge up to 100% preferably on a sunny day when I can get a few Kw free. Only use my 7Kw Zappi charger which then balances the battery. The last 15 minutes the input to the car drops progressively until it reaches 100%.
I am always ready for an emergency journey to wherever.
I have had the car since January and just done 3000 miles. This car should see me out.
 
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