Speak EV - Electric Car Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
40 Posts
Discussion Starter #1
What degrades the battery most ;

a) Quick Charging all the time
b) Granny plug charging all the time
c) Another scenario

Thanks!
 

·
Registered
Joined
·
1,906 Posts
What degrades the battery most ;

a) Quick Charging all the time
b) Granny plug charging all the time
c) Another scenario

Thanks!
With Leaf, there is a linear predictable age related 3% average degradation. Besides that rapid charging all the time will definitely up the degradation rate.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

·
Registered
Joined
·
40 Posts
Discussion Starter #3
Thanks. I notice from LeafSpy that my battery has only had 7 QC and over a 1000 L1 - could that be what has contributed to the 96% SoH after 36k miles? A happy coincidence maybe that the previous owner never used public chargers?
 

·
Registered
Joined
·
233 Posts
What degrades the battery most ;

a) Quick Charging all the time
b) Granny plug charging all the time
c) Another scenario

Thanks!
Using the granny cable a lot will have been good for the battery. It will be pushing in a slow, steady rate of charge into the battery. Far better than lots of rapid charges which can definitely be bad and cause early degradation. Another thing you didn't mention is leaving the battery at a very high or very low state of charge for too long. That can be equally as harmful as high temperatures or too much DC charging for example.
 

·
Registered
Joined
·
1,906 Posts
Thanks. I notice from LeafSpy that my battery has only had 7 QC and over a 1000 L1 - could that be what has contributed to the 96% SoH after 36k miles? A happy coincidence maybe that the previous owner never used public chargers?
Another factor worth keeping in mind is that no 2 Li-ion cells are alike.
Taking care of charge (and discharge) rates will increase the life of pack.

Two Leaf purchased on the same day are likely to have very different SoH over a period of time.

To add to confusion, various versions of Leaf HV battery controller calculate SoH differently.

4A & 4B variants were reporting massive losses and Nissan issued firmware updates. 6A variant tend to be overly generous.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

·
Registered
Joined
·
40 Posts
Discussion Starter #6
Thanks for the replies. I am guessing that 7.2kW home chargers fall somewhere in the middle or to the lower range for degradation?
 

·
Registered
Joined
·
233 Posts
Thanks for the replies. I am guessing that 7.2kW home chargers fall somewhere in the middle or to the lower range for degradation?
It will be less than that anyways, either 3.3 or 6.6 depending on what charger you have built in to your car. I would generally consider all AC charging to be low risk to degrading the battery, as long as you also are mindful of my previous post about not charging to 100% and leaving it like that for days/weeks for example.
 

·
Registered
Joined
·
40 Posts
Discussion Starter #8
Thanks. Must admit am feeling slightly better about all this now I know a bit more and have had great answers on the forum. Mostly I can charge at home but a few time a year I will have to use public chargers for longer journeys.
 

·
Registered
Joined
·
1,906 Posts
Granny charger isn't right for long term usage.
It is a fire hazard unless the wiring is dedicated - capable of 10A continuous.

3.3 & 6.6kW like 2.4kW granny charger have no impact on overall degradation.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

·
Registered
Joined
·
233 Posts
Thanks. Must admit am feeling slightly better about all this now I know a bit more and have had great answers on the forum. Mostly I can charge at home but a few time a year I will have to use public chargers for longer journeys.
The occasional public charge is absolutely fine. Even multiple in a row, getting the battery temperature into the red zone is mostly fine if it isn't a regular usage pattern. I wouldn't consider that particularly harmful and have done the above before with trips like Edinburgh>Oswestry>London>Newcastle in just over 24 hours of DC charge after DC charge, and only motorway driving and minimal time for me to eat or sleep between it to give not much time to cool back down. There was no long term impact on my SOH after that or a few other long journeys I have done with my 30kWh LEAF.
 

·
Registered
Joined
·
40 Posts
Discussion Starter #11
My granny charger is a on a dedicated outdoor socket and behind a separate 32A mcb however I am getting a Rolec fitted in the next week or so...
 

·
Registered
Joined
·
1,906 Posts
My granny charger is a on a dedicated outdoor socket and behind a separate 32A mcb however I am getting a Rolec fitted in the next week or so...
Excellent. I debated a dedicated housing for brick but if granny charger. In the end however dedicated 7kW point was far easier option.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

·
Registered
Joined
·
151 Posts
Its not the dedicated wiring that is the issue with the granny charger (though that can be an issue) its the fact that it doesn't have a dedicated earthing rod and your car can be at a different potential to the house (in terms of earths) or so I have heard from some more knowledgeable folks than myself.
 

·
Registered
Joined
·
1,972 Posts
Its not the dedicated wiring that is the issue with the granny charger (though that can be an issue) its the fact that it doesn't have a dedicated earthing rod and your car can be at a different potential to the house (in terms of earths) or so I have heard from some more knowledgeable folks than myself.
The earthing issue is that in the event of a broken Neutral/Earth conductor fault on the incoming supply to your house, a dangerous voltage difference can arise between the house earth and the outside ground you are standing on. Inside the house this is not a problem, as the within the house the incoming gas and water pipes etc are (should be) connected to the house earth, so everything inside the house is at the same potential; the danger arises if you are outside some distance from the house, when there could be the dangerous potential difference between the car body and the ground you are standing on.
 
1 - 14 of 14 Posts
Top