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Here is an interesting post from a taxi firm in Cornwall. They have 5 or 6 (can't remember which!) Nissan Leafs. They have installed their own rapid charger to charge them and the cars get rapid charged 2-3 times every day. If there was to be any evidence that rapid charging, in itself, damages the battery or significantly reduces its life, then surely it would show up there?

C&C taxis posted this today on Twitter:

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Nissan started out saying that we should all try not to rapid charge as they were uncertain of the effect but more recently they have been clear what they consider to be acceptable. Nissan say no more than 365 rapid charges per year (average of one per day).

This is evidence that even upwards of a 1000 charges in a year hasn't done this car much harm.

I have always said... don't rapid charge if you don't need to but do it when you do need it safe in the knowledge that you are unlikely to be doing it any significant harm. I may need to reassess that opinion to be even less conservative. I will rapid charge when I want and not worry about it now.

The caveat though is battery temperature. Charging many times a day, especially to more than 80%, will increase the temperature of the battery and that could have a significant detrimental effect. Keep the temps down and it looks like rapid charging itself may not be the issue we all thought it to be.
 

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The life of the cells seems to be related to the number of full cycles (ie fully depleated to fully charged) the more times this takes place the shorter the life. Some vehicles have BMS that actively try and balance the cells at the final fully charged voltage, but when the pack is substantially depleated some cells will be more badly depleated than others these can get damaged but still perform OK for most of the usage cycle. When a pack isnt put through this extreme cycling such problems dont get chance to become a problem. Cold is another issue, Lifepo4 or Lion dont line 0c (ish) and dont charge as well and dont discharge as well. Some vehicles use heating of the pack to get over this. But that heating takes a long time to permeate through the whole physical pack, down to the centre of each cell plate. If you charge as soon as you finish driving the pack will still be warm and will take a better charge. Leave it to cool down and charge on eco7 and you wont get as good a charge. So doing a number of rapid charges in the day, means they probably dont get fully charged or fully depleated, they get charged and discharge in a warmer state, (Not too hot as arizona has shown to give problems). Just the usage in which they seem to work at their best .
If you want these cells to live long, one approach is never to fully / maximum charge the cells, it also lessens the chance of any cell going high voltage on charge as they age. Rapid charge shuts off earlier / at a lower voltage to ensure the cells dont get driven over voltage. To get the higher current through the cells, you have to apply a higher voltage, to get the last 20% into the cell at a higher rate would take the cells into a very high voltage situation, hence the stop at around 80% on rapid charge.
If they constantly took the packs right down to the maximum depleation point I do think they would be heading towards problems, I doubt that they do that.
 

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I am not the battery "Geek" my husband is but I will tell you our cars are often run down to nothing, even to turtle mode. Other times they are drip fed on the Rapid charger during the course of the day. Some are Rapid charged to 80% then put on a level 2 charger to top them to 100% so they can do one of our long contracts.
 

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I am not the battery "Geek" my husband is but I will tell you our cars are often run down to nothing, even to turtle mode. Other times they are drip fed on the Rapid charger during the course of the day. Some are Rapid charged to 80% then put on a level 2 charger to top them to 100% so they can do one of our long contracts.
Excellent information Michelle, thanks for sharing! (And, welcome).
 

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I am not the battery "Geek" my husband is but I will tell you our cars are often run down to nothing, even to turtle mode. Other times they are drip fed on the Rapid charger during the course of the day. Some are Rapid charged to 80% then put on a level 2 charger to top them to 100% so they can do one of our long contracts.
Do you guys have a "Leaf-Spy" or "Leaf-DD" for monitoring the capacity & health of the batteries in your 6 high-mileage Leafs? 70k miles sounds like a UK record as of now!
Time spent at high temperature (and at high SOC as well) seem to be far more of an issue than the miles driven, number of charges, and/or rapid charging to 80% twice a day.
 

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Do you guys have a "Leaf-Spy" or "Leaf-DD" for monitoring the capacity & health of the batteries in your 6 high-mileage Leafs? 70k miles sounds like a UK record as of now!
Time spent at high temperature (and at high SOC as well) seem to be far more of an issue than the miles driven, number of charges, and/or rapid charging to 80% twice a day.
Yes we run Leaf Spy. Not all of our Leafs are High mileage as we have bought them over the course of 16 months, the last one a couple of months ago.
I believe our 70k is the highest mileage UK built leaf. The cars are charged back up to 100% during the day.

Our first Leaf (our only Japanese built Leaf) name is Sparky.
 

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I have just worked out you need to have about 500 solar PV panels on your office roof (or out in a field like in Germany)... To supply two rapid chargers recharging 6 Leafs doing 250k miles per year... Hope that helps?
 
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I have just worked out you need to have about 500 solar PV panels on your office roof (or out in a field like in Germany)... To supply two rapid chargers recharging 6 Leafs doing 250k miles per year... Hope that helps?
Yes we had worked that out and it wouldn't be very cost effective!
The 6 Leafs should do in excess of 300k in a full year. Though EV 7 and 8 are joining us shortly.
 

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Yes we had worked that out and it wouldn't be very cost effective! The 6 Leafs should do in excess of 300k in a full year. Though EV 7 and 8 are joining us shortly.
Great to hear your business is so successful. But your annual cost of electricity must be ~£8,000. Wow!
 

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Great to hear your business is so successful. But your annual cost of electricity must be ~£8,000. Wow!
But to put that into perspective compare it to the cost to fuel the diesels they are replacing.
 
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But to put that into perspective compare it to the cost to fuel the diesels they are replacing.
Yes, more like £38,000 per year for diesel. Annual saving is thus ~£30,000. You can buy two more Leafs with that...
 
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Your Maths are way out.....but we had to buy the 6 Leafs and the charging infrastructure....there's more to it than just electric.
 

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Start a Milton Keynes branch, they've got the government paying for taxi charging rapids! ;)
From a public point of view that's terrible. Our council wouldn't let you use their 16amp charger if you were desperate. They have had the funding for public chargers for a year, when we will actually see them is another matter but we are self sufficient anyway.
Are there many EV taxis in MK?
 

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There are no EV taxis in Milton Keynes.
You have a council with as much common sense as ours. Maybe it's to encourage Taxi /private hire firms to make the change?
 

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You have a council with as much common sense as ours. Maybe it's to encourage Taxi /private hire firms to make the change?
I wouldn't even want to guess what they're thinking.

I think EV taxis are a brilliant idea, what better way to "meet" EVs than that? But I think your approach is better all round,

Surely seeing someone actually making it work is better than short-term council supported infrastructure and free-charging, that's just giving totally false, tax-payer funded economy and a potential future disaster.
 

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There are no EV taxis in Milton Keynes.
But there are EV taxis in West London that use the Ecotricity M4 rapid chargers near Heathrow. I suggested a fair use policy (of say 10 rapid charges per month max) be introduced by Ecotricity, but Ecotricity (bless them) said it's OK at present, and to be fair, the hard-working young entrepreneurs do move off the Hounslow Rapids when visitors from the West need to stop by and rapid charge en-route to & from London.
 
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