Nissan does not recommend Trickle-Charge?

[planet4ever]

Hmm--So, i pug in wall then car? I thought i read the opposite on here.plug in car then wall?Which 1?

Think of it this way: The EVSE (the "brick" on the charging cord) is basically an electronic switch with some safety interlocks and checks. That switch cannot be turned on until the car says it's OK. So when the cord is not plugged in to the car, the switch is OFF. Plugging into the wall in that situation is like plugging in a lamp that is turned off. No problem. But if you were to plug into the wall when the switch was ON, it might suddenly start pulling 1,440 watts while you were still inserting the plug into the wall. Not good.

Now, in truth it's not quite that simple. In the first place, the EVSE itself does pull a few watts, so it's more like plugging in a night light. But no one has ever seen an electrical arc from plugging in a night light. (Well, OK, unless there was a short inside the night light.) And on the other end, the car doesn't tell the EVSE to turn the switch on until the two units have communicated a bit. The EVSE can't communicate until it has power, and it only gets power from the wall. So really, the only exposure would be if (say) you were starting to plug into the wall and suddenly sneezed, or heard a scream from your wife. You might have made the wall contact long enough for the EVSE and car to have their little chat, and then partially broken it, causing an arc. If your fingers were right there, that could be a bit unpleasant.

Ray

 

[davewill]

Hmm--So, i pug in wall then car? I thought i read the opposite on here.plug in car then wall?Which 1?

Think of it this way: The EVSE (the "brick" on the charging cord) is basically an electronic switch with some safety interlocks and checks. That switch cannot be turned on until the car says it's OK. So when the cord is not plugged in to the car, the switch is OFF. Plugging into the wall in that situation is like plugging in a lamp that is turned off. No problem. But if you were to plug into the wall when the switch was ON, it might suddenly start pulling 1,440 watts while you were still inserting the plug into the wall. Not good. ...

Can't happen. The EVSE's relays will be open when you plug it in, and they won't close until the EVSE powers up, puts out the proper pilot signal, and the car then signals back to close them. It truly doesn't matter what order you plug them in. Now, unplugging the car end first is vital. If you unplug from the wall while charging, it will cause arcing.

 

[planet4ever]

Can't happen. The EVSE's relays will be open when you plug it in, and they won't close until the EVSE powers up, puts out the proper pilot signal, and the car then signals back to open them. It truly doesn't matter what order you plug them in. Now, unplugging the car end first is vital. If you unplug from the wall while charging, it will cause arcing.

Good point on the unplugging end. In the final paragraph of my post (that you didn't quote) I basically said the same thing you did on the plugging end, but I did come up with a couple of unlikely scenarios where it might matter.

Ray

 

[Nubo]

unplugging the car end first is vital. If you unplug from the wall while charging, it will cause arcing.

+1, this is the important part. You don't want to pull the wall plug while it is conducting 12 amps. Unplug the car first and that will allow the EVSE to do its job -- breaking the circuit without an arc.

 

[johnrhansen]

What order you unplug should only matter if you are interrupting the charge while it is still in process. Once the charging is complete, there is no current to be interrupted, and no arc will be created. However people are creatures of habit, and it's good to do things in a way that is safe no matter what, and do it the same way every time. Use a checklist if you find yourself forgetting, or affix a big label to the power plug. DISCONNECT CAR FIRST.

 

[donald]

For my general edification, y'all seem to be talking about 'trickle-charging' in a consistent manner as if it was a well understood term, whilst as far as I am aware it is a technical term meaning something quite different and that is not to be used with Li-ion technology.

Please can you define what you mean by 'trickle charging'. Do you, simply, mean a low charge rate?

 

[dgpcolorado]

For my general edification, y'all seem to be talking about 'trickle-charging' in a consistent manner as if it was a well understood term, whilst as far as I am aware it is a technical term meaning something quite different and that is not to be used with Li-ion technology.

Please can you define what you mean by 'trickle charging'. Do you, simply, mean a low charge rate?

Yes. "Trickle charging" as used with the LEAF refers to using a 120 Volt, 12 Amp EVSE (in North America, at least). The one supplied with the car is often called the "trickle charge" cable or something like that. As used here "trickle charging" has nothing whatever to do with slow charging a lead-acid battery or anything like that. The term is intended to suggest how slow Level 1, 120 Volt, charging is compared to Level 2 charging or DCFC "quick charging". The term is used in the LEAF manual and has been adopted here.

 

[surfingslovak]

For my general edification, y'all seem to be talking about 'trickle-charging' in a consistent manner as if it was a well understood term, whilst as far as I am aware it is a technical term meaning something quite different and that is not to be used with Li-ion technology.

Please can you define what you mean by 'trickle charging'. Do you, simply, mean a low charge rate?

This is clearly spelled out in the owners manual, which can be confirmed trough any search engine. I specifically mentioned what this term means in the context of the Nissan LEAF it in my post upthread. While I'm also familiar with this term from another domain, I did not have trouble accepting its new meaning here. Why does this constitute such a problem and how much time do we intend to spend on this topic? Do you really believe that any manufacturer would recommend lead-acid style trickle charging for lithium-ion batteries?

Click to open

 

[donald]

Yes. "Trickle charging" as used with the LEAF refers to using a 120 Volt, 12 Amp EVSE

Thanks for the clarification.

 

[surfingslovak]

Yes. "Trickle charging" as used with the LEAF refers to using a 120 Volt, 12 Amp EVSE

Thanks for the clarification.

Happy to help, Donald.

 

[mapperboy]

I'm a new Leaf owner.
Sorry to crack open this old can of wormy posts about Leaf charging but here goes...

There's a lot of literature about recommended charging cycles, 'smart' charging and 'conditioning' circuit technology for the various battery chemistries (Lead Acid, NiCad, NiMh, Li Ion etc.) I can find absolutely no evidence that a slow trickle charge harms a Li Ion battery pack. The only caveat from most Li-Ion battery fact sheets and experts is that a trickle charge should not continue past the max charge state. Our Leaf trickle chargers do shut off the current when 100% charge is reached.

Primarily Nissan seems to be basing their 'Trickle Charging Is Not Recommended' statement in the owners manual more on corporate risk management, legal liability and bad press than any potential degradation or harm to the vehicles battery pack itself. There's a real fear by Nissan that the owners of homes or facilities of any age may have 110V outlets that are not properly grounded, in bad physical condition or not wired to a proper 15 A breaker and therefore potentially unsafe. This is in keeping with the curious statement also in the owners manual that the standard equipment 'trickle' charger SHOULD NOT be plugged into a 110V receptacle in a house or structure 40 years of age or older.

Wow, I'm glad Nissan knows the state condition of my recently upgraded 200 A service in my renovated 100 year old house as well as the new 60 A feed to my garage. Obviously this is more input from the Nissan legal dept to the owners manual copy-editors, again with the aim at reducing consumer litigation and bad press against Nissan. Where did they get that 40 years or older figure anyway.

My dealer's tech rep has told me that their theory about these owners manual trickle charge 'recommendations' are also driven by the potential unreliability of the trickle charge bricks themselves. I was told the service dept of my dealer has seen a few of the trickle charge bricks brought in by customers which have actually burned out and partially melted. BTW Nissan (in Canada at least) apparently refused to replace those burned out chargers claiming some kind of misuse must have taken place by the owner/user. In Canada a new Leaf replacement charger will set you back around $1,500 which is of course mostly because of the specialized, low volume captive market. I don`t recommend doing this but If you have experience with building electronics projects, take a look at what`s inside one of these bricks: http://www.instructables.com/id/313CONVERTING-A-2013-LEAF-LEVEL-1-12AMP-CHARGER-TO/?ALLSTEPS
This is definitely not $1,500 worth of plastic case, wire, cable and components.

Wonderful that we have so much misinformation, misdirection and rumour around certain aspects of the main critical power systems that power these EVs and that we are completely dependent on and owners!

I love my Leaf, but come on EV industry, get your act together and publish real facts about these vehicles and their electrical systems, not recommendations based on legalistic jargon and fears and myths.

 

[TimLee]

... Where did they get that 40 years or older figure anyway.

...

Not sure.

But I have replaced early Romex that was installed in late 1940s and in 1950s.
Absolutely unsafe.
A fire waiting to happen.

40 years is around 1975.
That may be when plastics technology improved enough for the insulation to be reliable for a long time.

I think Nissan was being prudent.
120V charging is only safe if you do the appropriate checks.

 

[LeftieBiker]

Not directly relevant, but the "brick" that plugs into the car is called an "EVSE" - an acronym for "Electric Vehicle Service Equipment." It is not a charger, just a kind of smart charging cable that provides the car's on-board charger with the appropriate supply of power, and a verified ground. The only external "chargers" are the DC fast chargers, which are the very large, heavy units that plug into a separate Fast Charge port (if present) on the car, and, bypassing the on-board charger, charge the pack directly at both high voltage and high current.

 

[RonDawg]

... Where did they get that 40 years or older figure anyway.

...

Not sure.

But I have replaced early Romex that was installed in late 1940s and in 1950s.
Absolutely unsafe.
A fire waiting to happen.

40 years is around 1975.
That may be when plastics technology improved enough for the insulation to be reliable for a long time.

I think Nissan was being prudent.
120V charging is only safe if you do the appropriate checks.

Personally I don't think that 40 year point is all that reliable either, because in the 1970's aluminum was widely used in both residential and commercial wiring. That is a big hazard as well.

 

[RonDawg]

My dealer's tech rep has told me that their theory about these owners manual trickle charge 'recommendations' are also driven by the potential unreliability of the trickle charge bricks themselves. I was told the service dept of my dealer has seen a few of the trickle charge bricks brought in by customers which have actually burned out and partially melted. BTW Nissan (in Canada at least) apparently refused to replace those burned out chargers claiming some kind of misuse must have taken place by the owner/user.

That's because in many if not most of the cases, there was misuse. Specifically, people rigging up some sort of adapter and plugging in the OEM L1 EVSE into a 200+ volt outlet, because "the internet said it was OK to do so."

There is a way to modify the L1 EVSE to be dual voltage (a company called EVSE Upgrade, owned by a member here, does just that for around $300) but these folks had just plugged these EVSE's directly into higher voltage without any such modifications, or with incorrect modifications.

Nissan USA as well as Canada is aware of this practice and there is a TSB instructing techs to open up the EVSE "brick" and look for telltale damage when someone complains that the OEM EVSE refuses to charge.

AFAIK there have been few legitimate complaints about the OEM EVSE being unreliable. There have been far more complaints about certain L2's like the GE WattStation causing problems.

 

[Nubo]

A lot of good things tend to happen (though not guaranteed) when someone sets up L2 charging for their EV

- dedicated circuit
- permanent or semi-permanent installation
- involvement of a qualified electrician and/or permit inspection
- general check of wiring/ breaker panel, load calculations, etc...
- adequate wiring for the application

In general, there's a much greater likelihood that the car charging will be taking place over a properly-wired and utilized circuit, compared to a 120V household outlet which is unlikely to be on a dedicated circuit.

If I were selling an EV, I'd certainly encourage use of L2 over L1.

That being said, I charged on Level 1 for a few months when we initially got the LEAF. But I did verify the wiring gauge, determined what other loads were on the circuit, and installed a new receptacle using side terminals instead of the common stab-in connections. And then checked for warmth during charging. Lots of people figure a plug is a plug....