Charging procedure of Chevy Bolt EV

Level 2 charging is always preferable to level 1 for several reasons. However, if one doesn't have access to L2, then L1 is a decent get-by.

As I've noted, we have three EVs, two charge L2 and the third charges L1.

The main advantage is ability to recharge faster when you need it. However, this aside L2 has some additional advantages...

1. Level 2 is generally more efficient

example: https://avt.inl.gov/pdf/fsev/SteadyStateLoadCharacterization2015Leaf.pdf
Leaf charging efficiency 78% at 120V, 90% at 208V

2. L2 allows you more flexibility to schedule charging since the charging interval is shorter. Even if time-of-use charging is not a factor for you (it isn't for me), then L2 allows you to charge "just in time" for departure. This lowers the average charge state of the battery and prolongs battery life.

www.nrel.gov/docs/fy12osti/53817.pdf

DucRider said:

Plus, I'm reasonably sure Chevy will make the same recommendations for the Bolt as the Spark EV:

Do not allow the vehicle to remain in temperature extremes for long periods without being driven or plugged in. It is recommended that the vehicle be plugged in when temperatures are below 0°C (32°F) and above 32°C (90°F) to maximize high voltage battery life.
In order to maintain maximum range from the battery, fully charge the battery at each charge event. It is not recommended to partially charge the battery.

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(emphasis added)

That is an odd recommendation. It flies in the face of what we know about Lithium batteries, and that Michael alludes to when he says:

michael said:

L2 allows you to charge "just in time" for departure. This lowers the average charge state of the battery and prolongs battery life.

http://www.nrel.gov/docs/fy12osti/53817.pdf

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In fact, in all lithium batteries that I'm aware of, charging to full is more stressful than charging to, say, 80%. Nissan even has a "long life mode" in which they charge only to 80% (although it was removed from 2014 on in the US for stupid regulatory reasons, it remains in the cars elsewhere).

DucRider said:

Note: 8 A is the default L1 charge rate on many EV's, you may need to change that setting if you have a circuit that will support a higher continuous load.

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The only EVs I know of that default t 8A are the Volt/ELR. I don't know of any non-GM EV that has this "feature". So it hardly follows that "many" EVs charge at 8A. Of course, the Bolt is a GM product so it would make sense if it too defaults to 8A.

michael said:

Level 2 charging is always preferable to level 1 for several reasons. However, if one doesn't have access to L2, then L1 is a decent get-by.

As I've noted, we have three EVs, two charge L2 and the third charges L1.

The main advantage is ability to recharge faster when you need it. However, this aside L2 has some additional advantages...

1. Level 2 is generally more efficient

<span>example: https://avt.inl.gov/pdf/fsev/SteadyStateLoadCharacterization2015<a href="http://www.mynissanleaf.com" class="interlinkr">LEAF<span class="tip">Visit the LEAF Forum</span></a>.pdf</span>
<span><a href="http://www.mynissanleaf.com" class="interlinkr">LEAF<span class="tip">Visit the LEAF Forum</span></a> charging efficiency 78% at 120V, 90% at 208V</span>

2. L2 allows you more flexibility to schedule charging since the charging interval is shorter. Even if time-of-use charging is not a factor for you (it isn't for me), then L2 allows you to charge "just in time" for departure. This lowers the average charge state of the battery and prolongs battery life.

http://www.nrel.gov/docs/fy12osti/53817.pdf

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Agreed on both points. I never argued that L1 would necessarily be preferable but only that it would be sufficient. And recommending someone install an L2 at home isn't necessarily bad. Although a strong blanket assertion that they will need L2 can certainly deter a prospective buyer. I also disagree that L2 is *always* preferable to L1. Here are two advantages of L1:

1) Cost. L2 can cost a few hundred to a few thousand dollars to buy the EVSE and wire the circuit. It can get much higher if major rework is necessary. By contrast, L1 can often be done for "free". All EVs currently on the market come from the factory with an L1 charge cord. Many people have access to a 15A / 120V circuit. All that's left to do is to plug in the car.

2) Stress. This likely won't be an issue with the Bolt, but it's worth pointing out. L2 is 3-6x faster than L1. That means it puts 3-6x as much current into the battery. Since Power is proportional to the square of current, the heat generated in the battery will be 9-36x as great. This absolutely makes a difference in Leafs, even in moderate climates like upstate NY. It noticeably heats up the battery while charging, which can cause damage and capacity loss. Again, likely not an issue with the Bolt because of its cooling system. But since you said L2 is "always" better than L1, I thought I'd mention this.

GetOffYourGas said:

It flies in the face of what we know about Lithium batteries, and that Michael alludes to when he says:

michael said:

L2 allows you to charge "just in time" for departure. This lowers the average charge state of the battery and prolongs battery life.

http://www.nrel.gov/docs/fy12osti/53817.pdf

Click to expand...

In fact, in all lithium batteries that I'm aware of, charging to full is more stressful than charging to, say, 80%. Nissan even has a "long life mode" in which they charge only to 80% (although it was removed from 2014 on in the US for stupid regulatory reasons, it remains in the cars elsewhere.

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Just how Li batteries work and degrade is a bit of a mystery even to scientists working on them, and different chemical and design variations create different strengths and weaknesses. Not a ll Li batteries are created equal. The one universal truth is - "Heat Kills". Some chemistries are more resistant to heat, and many improvements have been made since that 2012 study you posted. Nissan themselves have released their new "Lizard" battery that is less susceptible to heat degradation (and may be part of the reason they dropped the "charge to 80% recommendation - along with being able to get a higher EPA "apples to apples" range rating). With no thermal management, Nissan (and VW) need to rely on the user to take extra precautions to preserve battery life. Other manufacturers have elected to use various types and degrees of active thermal management to control the biggest factor in battery degradation - heat.

Honda Fit EV FAQ said:

Q: Will "topping off” every night damage the battery?
A: No, "topping off" will not damage the battery.

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No Honda Fit EV owner has reported ANY range degradation - even at 50K + miles. The Fit EV uses Toshiba SCiB batteries, has active air cooling, 7.2 kW L2, but no QC capabilities. The Toshiba batteries have other tradeoffs, but have been fantastic in range retention. Might be partly why Honda is sending the returned Fit EV's back out for a second round of leases (2 years on the used ones).

Plus, the Battery Management Systems never allow you to charge the battery to 100% - or discharge to 0%. The State of Charge we see is % of usable pack size - some manufacturers are more conservative on what they let you use, some are more aggressive. Sometimes those numbers are available, sometimes not.

The BMW i3 has 18.8 kWh usable from a 21.6 kWh pack. Soul EV 27/30.5, Volt is reported to be 14/18.8, B-Class 28/36 (pre 2015? )

GetOffYourGas said:

The only EVs I know of that default t 8A are the Volt/ELR. I don't know of any non-GM EV that has this "feature". So it hardly follows that "many" EVs charge at 8A. Of course, the Bolt is a GM product so it would make sense if it too defaults to 8A.

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Volt, ELR, Spark EV, i3, i8, B-Class all default to 8A (or did at some point - that may have changed). Tesla allows you to set the charge rate, and will in fact reduce it automatically if it senses a voltage drop. There was a garage fire a couple years ago that started in the outlet where the Tesla charge cord was connected (240v in this case). A loose connection or corrosion created greater resistance, the outlet overheated and eventually caught fire. I think Tesla implemented the charge rate reduction after the fire.

As a side note, the J1772 standard allows for thermal detection at the handle/car connection, but it is not always implemented. Honda released an update to the Fit EV that allowed it to charge at a reduced rate rather than stop the charge completely when excess heat was detected. This is/was common on Blink EVSE (public and private) that had defective handles with incomplete crimps resulting in poor connections.

Hopefully a simple, non-technical question - I have a Voltage with a 208v. charger. Will I be able to use this charger for my Voltage AND Bolt? Will the plug be compatible? Thank you!

rbauman said:

Hopefully a simple, non-technical question - I have a Voltage with a 208v. charger. Will I be able to use this charger for my Voltage AND Bolt? Will the plug be compatible? Thank you!

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Yes

rbauman said:

Hopefully a simple, non-technical question - I have a Voltage with a 208v. charger. Will I be able to use this charger for my Voltage AND Bolt? Will the plug be compatible? Thank you!

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It should be compatible with Bolt EV.

GetOffYourGas said:

Airports are tricky because you could be leaving your car there for a week, yet need to have a full charge when you return. In those cases, you'd either want some sort of valet service to move cars around, or an L1 system that is cheap enough to scale with demand.

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Nashville airport is no trouble.

Park at 3rd party parking facility. They charge your car while you are away. Return to charged car.
The alternative is to park at Airport parking lot and use CHAdeMO unit either as you arrive or as you leave.

michael said:

That's fine until someone comes along who needs to charge up and finds another car plugged in.

I believe if you don't need a charge, don't occupy the spot. And move your car as soon as practical after charging is complete

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Experience teaches me the ABC's of charging.

Always be charging.

There is that unexpected trip you need to make shortly after reaching your destination. Then you regret not taking the extra charge when you had the opportunity.

I leave a note inside the car with the time when its OK to unplug and cell number.

JPWhite said:

GetOffYourGas said:

Airports are tricky because you could be leaving your car there for a week, yet need to have a full charge when you return. In those cases, you'd either want some sort of valet service to move cars around, or an L1 system that is cheap enough to scale with demand.

Click to expand...

Nashville airport is no trouble.

Park at 3rd party parking facility. They charge your car while you are away. Return to charged car.
The alternative is to park at Airport parking lot and use CHAdeMO unit either as you arrive or as you leave.

Click to expand...

I think you misunderstand my point. I'm talking about installing infrastructure, not using it. Unless that third party moves your car when you are done? Otherwise what happens when you get there and all plugs are in use, with the cars' owners gone for a week, and all cars are done charging?

GetOffYourGas said:

JPWhite said:

GetOffYourGas said:

Airports are tricky because you could be leaving your car there for a week, yet need to have a full charge when you return. In those cases, you'd either want some sort of valet service to move cars around, or an L1 system that is cheap enough to scale with demand.

Click to expand...

Nashville airport is no trouble.

Park at 3rd party parking facility. They charge your car while you are away. Return to charged car.
The alternative is to park at Airport parking lot and use CHAdeMO unit either as you arrive or as you leave.

Click to expand...

I think you misunderstand my point. I'm talking about installing infrastructure, not using it. Unless that third party moves your car when you are done? Otherwise what happens when you get there and all plugs are in use, with the cars' owners gone for a week, and all cars are done charging?

Click to expand...

When you arrive at the 3rd party parking facility they take care of parking your car, charging your car. They will even take a gas car for an oil change if you ask them/pay them to do so. There is no need for the airport to build infrastructure. The 3rd party parking lots take care of business, typically have quicker shuttle service, covered pickup location so you don't get wet walking to your car. A few bucks cheaper per day as well.

The Airport just needs enough infrastructure for transient traffic. Some L2's and an L3 or so in short term parking and they are good to go.

JPWhite said:

GetOffYourGas said:

JPWhite said:

Nashville airport is no trouble.

Park at 3rd party parking facility. They charge your car while you are away. Return to charged car.
The alternative is to park at Airport parking lot and use CHAdeMO unit either as you arrive or as you leave.

Click to expand...

I think you misunderstand my point. I'm talking about installing infrastructure, not using it. Unless that third party moves your car when you are done? Otherwise what happens when you get there and all plugs are in use, with the cars' owners gone for a week, and all cars are done charging?

Click to expand...

When you arrive at the 3rd party parking facility they take care of parking your car, charging your car. They will even take a gas car for an oil change if you ask them/pay them to do so. There is no need for the airport to build infrastructure. The 3rd party parking lots take care of business, typically have quicker shuttle service, covered pickup location so you don't get wet walking to your car. A few bucks cheaper per day as well.

The Airport just needs enough infrastructure for transient traffic. Some L2's and an L3 or so in short term parking and they are good to go.

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sounds like a great service! That's pretty much exactly what I had in mind when I mentioned a valet service in my original quote. Certainly a solution to the problem!

JPWhite said:

When you arrive at the 3rd party parking facility they take care of parking your car, charging your car. They will even take a gas car for an oil change if you ask them/pay them to do so. There is no need for the airport to build infrastructure. The 3rd party parking lots take care of business, typically have quicker shuttle service, covered pickup location so you don't get wet walking to your car. A few bucks cheaper per day as well.

The Airport just needs enough infrastructure for transient traffic. Some L2's and an L3 or so in short term parking and they are good to go.

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I disagree. L1 is perfect for long term parking. With L2 or even DCFC, you need to wait while the car charges (plugging in to either of those while on a trip is a waste of resources). With L1, you get to the parking lot, unplug the car and go.

The valet charging model works, but 3rd party parking location, convenience and price varies wildly at different airports. At PDX, the off-site lots are actually a little higher than the airports economy lot. None offer any EV charging service. If they did start offering charging, L1 would likely be the most cost effective solution..

PDX parking
Economy lots (24 free L1 EVSE's) $10/day
Long term garage (no EVSE's) $21/day
Short term garage (6 free L2's - almost always full) $27/day
Valet $30/day - free charging

Off site (Thrifty, etc) ~$11/day - no charging available

DucRider said:

JPWhite said:

When you arrive at the 3rd party parking facility they take care of parking your car, charging your car. They will even take a gas car for an oil change if you ask them/pay them to do so. There is no need for the airport to build infrastructure. The 3rd party parking lots take care of business, typically have quicker shuttle service, covered pickup location so you don't get wet walking to your car. A few bucks cheaper per day as well.

The Airport just needs enough infrastructure for transient traffic. Some L2's and an L3 or so in short term parking and they are good to go.

Click to expand...

I disagree. L1 is perfect for long term parking. With L2 or even DCFC, you need to wait while the car charges (plugging in to either of those while on a trip is a waste of resources). With L1, you get to the parking lot, unplug the car and go.

The valet charging model works, but 3rd party parking location, convenience and price varies wildly at different airports. At PDX, the off-site lots are actually a little higher than the airports economy lot. None offer any EV charging service. If they did start offering charging, L1 would likely be the most cost effective solution..

PDX parking
Economy lots (24 free L1 EVSE's) $10/day
Long term garage (no EVSE's) $21/day
Short term garage (6 free L2's - almost always full) $27/day
Valet $30/day - free charging

Off site (Thrifty, etc) ~$11/day - no charging available

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As with most things automotive YMMV.

At Nashville you can park for $8/day at a 3rd party lot. Their valet price is the same as self park.
https://www.flyawayparking.com/coup...5gHGmlQ0a4o6tv_AsObdm25ZH45ZPZTI30aAmSx8P8HAQ

I helped the manager at this location pick out some Clipper Creek EVSE's after he realized charging EV's using a 120v outlet wasn't scalable as he was receiving more and more charging requests from Tesla owners. They are very EV friendly.

I didn't realize until reading the customer reviews on their website that they offer free parking if your flight is cancelled.

In Nashville at least I see no reason to use airport parking unless I'm picking someone up.

I occasionally use the airports L3 unit in short term parking if I need a boost. It's just $3 a pop.

The plugs charging station and networks all need to work together for every electric vehicle the technology teams need to communicate with this as different types of charging apparatus is not a good thing electric vehicles need to be easy and efficient for their users

We need an open charge Point protocol for communication between EV charging stations and the central management Network much like our mobile phone networks have