120v for some reason has more wear on the batteries, the least amount of wear from charging is a L2 charger so you're actually golden right now.

The confusion is that there's no "standards" for any of this and automakers even change their buffer capacities mid-model runs but generally speaking what you're doing now is like perfect charging etiquette.

As a bonus if you didn't already know, do your best to park in the shade when the temps are over 70F.

 

120v for some reason has more wear on the batteries,

Not sure I understand why this is so. Do you have a source?

 

Don’t wait to charge until you’re at 30%. GM is encouraging charging often precisely because running the battery down low adds risk. Running down to 60% or even 50% is probably okay if you want to charge less often.

 

But then they say to charge after each use. But needs to be outdoors and attended. WTH. I'm not doing it. I'm still running mine down to about 35% but only charging once a week as I've always done. Don't tell anyone though. But it's also indoors and overnight while I sleep (but time it so it's done about the time I need to use the car). I've only done it two or three times since this whole thing hit the fan. Not doing it every day like they are suggesting.

 

Maybe this as my rough draft of a checklist:

1. Park outdoors
2. Charge outdoors
3. Charge often
4. Do not charge above 90%
5. Do not discharge below 30% (approx. 70 miles)

Possible adds:

6. Unplug after charge is complete
7. Set charge start time to begin late in the night (say 3 or 4 AM) to avoid it being plugged in very long prior to waking
8. Do not charge unattended (contradicts 6 & 7 above)

Feel free to hack away on this.

 

6. Unplug after charge is complete

It's better not to unplug if possible, since GM's battery monitoring will continue for several hours if you leave it plugged in.

 

I think it is 4 hours. Also get the last final fix software. It may just brick your car which is actually good.

 

The recall says to charge more frequently, don't charge over 90%, don't charge overnight, don't let GOM go below 70 miles before charging (not sure why they didn't just mention green bars), don't park in the garage immediately after charging.

Not sure it's best practice, but I will charge as follows:

1. Charge every evening when I get home (I burn about 8-9 kwh a day... so ~1 hour or so)... I charge to 80%.
2. Back the car out of the garage for 3-4 hours after charging (my EVSE is in the garage unfortunately)
3. Move the car back into the garage before I go to bed.

 

Just got my real license plates. Thinking of having custom frames "Dragon powered, beware of flames"😇

 

I am charging my 2022 Bolt EVU (having 780 miles on it using my GE WattStation (I have two and an SPX 220 volt that I quit using) t hat charged bolt of my Volts (2012 and 2015.)

When the recall was announced for the Bolt, I quit charging my Bolt and had to "educate myself" about charging straggles (never worried about that with my Volts...)

I'm leaving my Bolt at around 70 to 75% charged. I might drive it two or three times per week since buying it about 5 weeks ago, and when I drive it, I might put 30 or 40 miles on it in one outing, or less than 100 miles per week.

I live on a ranch in Texas and it is WICKED HOT here, but I continue parking my Volt in a "cow shed" I restored, now having concrete floor, metal roof and the interior is lined with cedar planks. Regardless of parking the Bolt outside (tall dry grass here on the ranch) or inside my cow shed, if she "goes up in flames" and I am confident the Bolt will not do that, parking it outside is a greater risk than parking it in the cow shed where it isn't in the sun.

As I write this comment, it is 99 degrees outside in the shade, and I am "cool" with keeping my 2022 Bolt in the cow shed out of the sun.

What really concerns me though is how this will impact not ME but how it will affect GM.Prior to the last time GM got into a financial bind, I had somewhere in the neighborhood of 800 shares on GM stock. When the stock took a nosedive, THAT HURT. And although I don't own GM stock today, this company has been in business since 1908 and I want it going strong, long after I am gone. I'm NOT WORRIED about my Bolt...

 

My charging strategy since day 1 ( before any of the recalls) have been to charge between 25%-75%, but mostly 45%-75%. My commute allows me to do this from the most optimal summer days to the coldest days of a Canadian winter. I know that not everyone can do that, but I guess I'm lucky to be able to do that. I also routinely charge outside at 120 V.

 

I have low daily mileage requirements so I had only been doing L1 charging (8A) in my garage (townhouse, so building is shared and there's no driveway for parking). With the new recommendations, it seems my choices are:

1. L1 charge in my garage for ~2 hours (a bit more during weekends) when I get home every day. Then, find street parking after charging. (Best as far as limiting range of charge levels, but requires more daily effort to find parking by the time the charge is complete.)

2. L2 charge once a week for ~3 hours at nearby public charger. Street parking every day. (Less daily effort but goes against recommendation to charge often. Also, public charger is ~40% more expensive and not always available. Charger at work is more accessible but more expensive.)

I'll see how it goes. Maybe I'll do a bit of both. It would be nice if I already had an L2 charger at home but prior to this, it didn't seem worth the bother of getting approval from my neighbors/HOA (since it's a townhouse) and an inspection from the city.

 

If GM had worried at all about L1 charging being any kind of degradation issue they wouldn’t have supplied every single Bolt with a 120v EVSE as standard.

 

I've got a 240v evse I got at the same time frame I got my Bolt
I keep it in the driveway all the time as my wife's car is in the garage
An electrician wired my 240v every with a 20 foot long extension so it would reach my Bolt so I can plug it in
I usually charge it once a week and run the battery down to around 60%
This works for me, and I've been doing this for 5 month's now we without a problem

 

Lot's of great comments on 120 vs 240. How about 240 12amp vs 240 32 amp? In other words, is there any benefit to adding a full EVSE vs using the stock EVSE with a 240v adapter/plug? A single 240v 12amp plug is plenty for my wife and I to keep our Bolt and Volvo topped off with our normal driving.

 

The answer for that is it truly doesn't matter.

Oversimplified:

What we're talking about specifically is by nature unless you want to spend more money and make your system more complicated, if you design an electric circuit for 240v and x amps you will generate more heat if you pass 110/120v through that same system.​

​

Think about it this way: Low voltage (110/120) needs more power (current) to PUSH through the resistance of of the metal it's traveling over. Without that power it can't overpower the resistance inherent in any imperfect conductor. That resistance and loss is manifested in the form of heat which is the reason why you can't plug an air conditioner into a 100' 18 gauge wire without starting a fire. When you're starting out at 220/240 you inherently have more power in voltage and it doesn't succumb as much to the resistance in the conductor (metal).​

​

tl;dr: Do not worry about varying currents for a L2, it should have a negligible if any impact on your long term battery health.

 

Thanks. Looks like I'll be installing a 240v plug in my new (old) house then that I move into next week. Good thing is the panel is right there and plenty of room for an extra breaker.

 

Our strategy is to follow the recall instructions and keep the darn thing outside all the time, especially while charging, until we can get Chevy to buy back our Bolt or get new battery packs, whichever comes first. This is the second recalled Bolt we've owned, so we're pretty annoyed. They bought back the first one. We've asked them to buy this one too. If we can get that done, we're done with Bolt.

 

I didn't get the impression we had to keep it outside at all times. Just that we should park it outside immediately after charging.

 

GM can "fix" my Bolt, but they will have to fight me to buy it back.
I'll sic my donkey (Pablo) on them if GM tries to buy it back... and Pablo can be a real jack ass sometimes and as an added "bonus" he has really bad breath...

 

Doesn't slow charge encourage dendrites and DCFC burns them off?

 

No, no, and no. DCFC could, maybe, possibly, occasionally cause a dendrite to burn off instead of creating a short. It's not like there are constantly growing thin little dendrite strands that must be burned off from time to time. Any dendrite getting through the separator is a serious potential issue. Their growth is erratic and unpredictable. Thinking that you could just DCFC once in a while to burn them off is false.

 

What is far worse for the batteries than L1 or L2 is charging to a higher SOC than you need at a hot temperatures
I would be way more worried about this. Also high kW discharge at very low SOC.

 

120v 12A = 1.44KW. @80% efficient, 0.288KW loss as heat.
240v 32A = 7.68KW. @90% efficient, 0.768KW loss as heat.

But neither of these are considered fast charginng.

 

But this is heat generated in the on board charger, not heat due to current flowing through the internal resistance of the battery cells.

Your statements confuse the efficiency of the charging electronics with the efficiency of the electrochemical reaction in the batteries as they charge.

 

I charged to 80% from 46% last night in the attached garage, The charge session ended at 7 am, prior to which I got up and went for a walk, getting 2 miles away from the house in the process. After charge completion, the car sits in the garage, as it will until I next use it, which will probably not be today unless something comes up.

This is no different than what happened before being recalled, and still follows the GM guidelines. They said to charge to 90% and then park outside. It’s not to 90% yet, so it stays in the garage.

I can’t stop an asteroid from taking the planet out, and I’m not able to park my hinny on a different planet in the meantime. Life goes on, I refuse to let a car in any way trash it.

 

I don't think heat from ordinary charging has anything to do with the fires because there haven't been any fires while fast charging, which is when the batteries would be subjected to the most heating. Instead, the issue is electromagnetic forces within the cell that results in a breach in the separator and in an internal short and very high heat in that cell. As I understand it, the internal forces that cause plating and dendrites that can breach the separator rise with a high or low state of charge and these forces act over time. I think the best we can do is to follow GMs instructions and not charge past 90% and not discharge past 70 miles unless it's really necessary. I've always normally charged to 80% and normally don't drive more than about 120 miles a day but If I need to, I'll still charge to 100%, but I won't let it sit at that SOC for long and I'll try to avoid running it down, If it's possible.

 

Speaking for myself:

I charge at home, outdoors (though under a carport).

I have my JuiceBox set to a max of 16A, I chose this setting to split the difference between the heat/charging time debate. When I used to charge at a public L2 charger near my work it charged at 32A and I didn't really worry about it.

I use Target Charge Setting exclusively and I have it set to finish charging 3 hours after I actually leave for work in the morning. With the 16A setting mentioned above that works out to me unplugging when the battery is at ~70% SoC.

I've always interrupted my charges to keep my battery at lower SoC but previous to the recall I would only allow my car to charge to "full" (~90% with Hill Top Reserve active) about every 1000 miles, I did this primarily for the benefit of the cell balancing that occurs at the end of the charge cycle. I'm no longer doing this and currently at about 1700 miles since my last "full" charge and don't plan to have another until after I get my battery/modules replaced which I expect won't happen until some time in 2022.

Previous to the recall I charged when I got to ~100mi of range which was usually about 40% but now I plug in (for an early morning charge) if my battery SoC is below 50% when I get home. In reality this means I keep my battery between ~45% and ~70%.

 

I think people are getting this all wrong. Normal charging has negligible or no effect on battery fires. If so GM would be including this in their advice. If they are and I missed it, well do what they say. Charging to high voltages gives the bad battery more potential energy to self discharge through a short circuit, be it a torn tab, dendrites or folded separator.
This self discharge over time boils away the electrolyte and what was a micro short becomes a runaway thermal event.
It also creates physical stress between parts as the cell expands. What might be a minor problem at 80% becomes a fire at 100%

 

And I still have to follow up. Your quoted part is exactly what I've been saying:

Thus, if we keep the voltage constant and double the current, losses will increase by a factor of four.

The voltage on the battery regardless of L1 and L2 are the same. L1 has less current. Just as you highlighted, if more current is offered at the same voltage, the losses will increase.

As I've stated before, the efficiency difference between L1 and L2 is the accumulation of losses over time. L2 has higher instantaneous losses because the current is higher (at the same voltage). But since it runs much less time than L1, those losses overall are less.

See? Google is my friend too.

ga2500ev

 

Sorry man, this is beyond your understanding. This is the last round I'm going through this not because I don't have the patience to explain something to someone but you're very hostile and very sure of yourself and what I'm talking about isn't within something that's questionable or an "advanced" concept in electricity. It's literally the second thing you learn.

If you are at 110v 15 amps your losses will be higher and your dissipation in the form of heat greater than if you're 220v 30 amps over the same circuit. This is not within question because the losses are 2x higher in the 110v 15amps and you can arrive to that conclusion by plugging in the variables into the math to the Google link I provided.

Can I please get an electrician to speak up?

 

Hello? It's me...

 

What was this thread about again?

 

Charging practices, re-rail this please, I'm done with obtuseness.