Question about fast charging

[ObjetDart]

I tried using our one local DC fast charger today for the first time. Mostly just out of curiosity.

It worked great, and it was free, which is nice. The only thing that surprised me was that the fast charge did not stop automatically at 80%, which I thought it was supposed to do in order to protect the battery from damage. I stopped it manually at 89%.

So, is fast charging supposed to stop automatically at 80%? I'm actually not sure where I got that idea in the first place.

 

[TonyWilliams]

If you started the charge above 50%, then it will normally charge to 100%.

If below 50%, then it will charge to 80%.

Of course, every charger works a bit differently.

 

[ObjetDart]

Ah, OK. I think it was just above 50% when I started.

Is fast charging above 80% considered to be worse for the battery than trickle charging above 80%?

 

[LEAFfan]

Ah, OK. I think it was just above 50% when I started.

Is fast charging above 80% considered to be worse for the battery than trickle charging above 80%?

I've QCd hundreds of times to 97-98% (rare to get 100%) with my previous 2011, and it still lost less capacity than most others. If you QC no more than two times a day in cooler weather it won't hurt your pack. High ambient heat over time is much worse on pack degradation.

 

[DaveEV]

If you started the charge above 50%, then it will normally charge to 100%.

The OP has a '13 LEAF. They always QC to 100% unless the charger is set to charge to somethig less.

If you QC no more than two times a day in cooler weather it won't hurt your pack. High ambient heat over time is much worse on pack degradation.

Keep in mind that a 20 minute QC will raise pack temperatures by about 10F. This is no different than sticking your car in 10F higher ambient temperatures for a good 12 hours that it takes for the battery to cool back down to regular temps.

I would expect that if you did 2 QCs daily, you would easily double your rate of capacity loss.

It is wise to only QC to the charge level that you need to comfortably reach your next destination to minimize wear and tear on your battery.

 

[cracovian]

The QC station also drastically reduces your amps as the battery gets fuller, so charging over 80% is usually not much faster (if at all) than a regular L2 at this point.

 

[ObjetDart]

Thanks for all the great tips, they are really helpful!

 

[LEAFfan]

If you started the charge above 50%, then it will normally charge to 100%.

The OP has a '13 LEAF. They always QC to 100% unless the charger is set to charge to somethig less.

If you QC no more than two times a day in cooler weather it won't hurt your pack. High ambient heat over time is much worse on pack degradation.

Keep in mind that a 20 minute QC will raise pack temperatures by about 10F. This is no different than sticking your car in 10F higher ambient temperatures for a good 12 hours that it takes for the battery to cool back down to regular temps.

I would expect that if you did 2 QCs daily, you would easily double your rate of capacity loss.

It is wise to only QC to the charge level that you need to comfortably reach your next destination to minimize wear and tear on your battery.

Sorry, no way that's true. I had QCd twice in a day many times, and the only reason my pack degraded was the high ambient temps over time. Many LEAF drivers lost more capacity than I did and they never used any QC. Please don't spread that misconception.

 

[LEAFfan]

The QC station also drastically reduces your amps as the battery gets fuller, so charging over 80% is usually not much faster (if at all) than a regular L2 at this point.

That's correct except for 2013s. I can QC to 90% in 30 minutes from LBW, sometimes in even less than 30 mins.

 

[DaveEV]

Sorry, no way that's true. I had QCd twice in a day many times, and the only reason my pack degraded was the high ambient temps over time. Many LEAF drivers lost more capacity than I did and they never used any QC. Please don't spread that misconception.

These are facts:

QC = higher battery temps.
Higher battery temps = faster capacity loss.

If you wish to argue otherwise, feel free.

 

[LEAFfan]

Sorry, no way that's true. I had QCd twice in a day many times, and the only reason my pack degraded was the high ambient temps over time. Many LEAF drivers lost more capacity than I did and they never used any QC. Please don't spread that misconception.

These are facts:

QC = higher battery temps.
Higher battery temps = faster capacity loss.

If you wish to argue otherwise, feel free.

Those are definitely not facts for here. Where you got that isn't accurate. Also, "faster capacity loss" doesn't mean the same as you previously posted. We have actual proof here with actual cars that show QCing will not degrade your pack nearly as much as HAH over time unless u QC many times within a short period of time.

 

[DaveEV]

We have actual proof here with actual cars that show QCing will not degrade your pack nearly as much as HAH over time unless u QC many times within a short period of time.

What proof? Are you talking about your anecdotal experience?

 

[TonyWilliams]

We have actual proof here with actual cars that show QCing will not degrade your pack nearly as much as HAH over time unless u QC many times within a short period of time.

QC = higher battery temps.
Higher battery temps = faster capacity loss

What proof? Are you talking about your anecdotal experience?

I don't think you'll be able to explain away that simple fact that charging at ANY speed heats up the battery.

Also, the faster you charge, and the higher the SOC% while charging will heat up the battery even more.

We know what heat does to these cells.

Seems pretty simple, wouldn't you say?

 

[LEAFfan]

We have actual proof here with actual cars that show QCing will not degrade your pack nearly as much as HAH over time unless u QC many times within a short period of time.

QC = higher battery temps.
Higher battery temps = faster capacity loss

What proof? Are you talking about your anecdotal experience?

I don't think you'll be able to explain away that simple fact that charging at ANY speed heats up the battery.

Also, the faster you charge, and the higher the SOC% while charging will heat up the battery even more.

We know what heat does to these cells.

Seems pretty simple, wouldn't you say?

Go back a few posts, where it was posted that QCing is worse on the pack than HAH over time. There was no disagreement about QCing heating the pack. Again, when many drivers lost bars here, it was NOT from QCing. It's surprising how some posters have either forgotten those facts or have chosen to ignore the facts.

 

[surfingslovak]

LEAFfan, human memory is famously selective. There are apparently many new owners and posters here too.

 

[LEAFfan]

LEAFfan, human memory is famously selective. There are apparently many new owners and posters here too.

Yes, of course, but I was talking about the posters that have been posting since the lost bar thread. I didn't want to name names.