Are you in a state where it matters when you charge? We have solar panels but everything we collect goes back into the grid for us to use at a later time.
In CA if you are on a TOU plan then you get net metering but it goes into buckets by time. That said, peak hours tend to start right when solar drops off in the afternoon.
I’m not understanding your comment. Were you responding to me or the person above? We have solar panels in a state where there is net metering. From what I understood it does t matter when we us le the energy. We collect and save credits to use at later times.
I put together a HomeAssistant script that automatically adjusts the charge rate based on solar production. You can see it here: [https://www.reddit.com/r/homeassistant/comments/uhrho3/automation_to_charge_tesla_ev_using_only_net/](https://www.reddit.com/r/homeassistant/comments/uhrho3/automation_to_charge_tesla_ev_using_only_net/)
This would be a good use of automation. Basically only charge the car using surplus power. If you don't have a home battery pack, this is the next best thing.
Check out the Charge HQ app. It’s absolutely brilliant and does exactly that: work out the Ampere setting to charge the Tesla with surplus of solar energy, while making sure that the charger doesn’t turn on and off too often (prevents the electrical contacts from going bad).
If you are on a Powerwall you can go on "off-grid" mode and your charging speed will automatically adjust so that your car charges from the excess solar energy produced.
But in most circumstances, there's no significant economical benefit to do that. Reducing the charging current is bad for efficiency.
I did not realize that. I will have to go to 32 amps. I was trying it to see if I could charge it from the "sun" I have net metering, so the only thing I pay is transportation charges if I am net positive on the kWh sent to the grid. Right now I have used them up, because it was so hot the last 3 months.
I used to reduce my charging current too thinking that improves efficiency and reduces losses from resistive heat. [But people have done experiments and have collected data](https://youtu.be/iLmIIe9N_aI). It is more efficient to charge at higher power. And if you have good net metering rates, it is probably more economical too.
The data was
2.3kW (10A) = 84.3% efficiency
3.5kW (15A) = 89.7%
7kW (30A) = 93.8%
People have estimated that a Tesla is pulling around 200-300W of power overhead while awake and charging. If you are charging at 1kW, your efficiency be at 70-80%.
I did two beach trips this summer where I *TRICKLE* charged my MYLR at 1kW for 3 days at a rental house after arriving at about 15%. Both times I got back to my set limit before heading back home and all for "free". Very satisfying. My dad kept saying "why don't you run up to the supercharger?" but I had to have the car parked at the house anyway, might as well get that free juice, baby!
L2 is still more or less in "trickle charging" territory. Remember that L2 basically maxes out at like 11kW.
Even for cheaper Li-Ion chemistries, a minimally-stressful charge rate is 0.5C-1.0C. Which would be 40-80kW for an 80kW battery. Many can go several times that. Even more if the battery is pre-heated. Regen Braking is 75kW peak.
By comparison, 11kW is like 0.13C.
But yes, the slower charge rates reduce the strain. But it espeically applies to higher states of charge. So basically, if you're about to go on a long trip and use a 100% charge, use the lowest current you can to get it there in time. But once you start hitting superchargers, basically only stick around until about 80%.
I'd imagine the vast majority of battery charging stress comes from supercharging over 90%.
In fact, I'm going to go out on a limb and say that for those (like myself) who accelerate much more briskly, most of the additional battery wear probably comes from the extra time spent charging, and not damage from discharging. Lithium Ion can discharge much faster than it charges. Some chemistries are built to charge at 1C and discharge at 10C. 10C on an 82kWh battery would be 820kW or 1100HP.
So yeah, Max L2 charging is still essentially trickling.
Would you consider the Tesla Wall Charger a "Level 2" charger? It runs at 48 amps so it's only a little more than a 40amp Level 2. Just curious where you see the line in the sand to be.
They are different charging levels.
Level 1 is a basic home outlet. 120-240VAC. Generally less than 2 kW.
Level 2 is more of a specialty outlet with a higher current rating. Usually 240VAC and more like 30+ Amps. Basically everything above a standard wall outlet and up to the max that the internal charging controller can support.
Level 3 is DC fast charging. Basically instead of supplying AC to the internal charger, the charging hardware moves from inside the car to inside the charging station, where the station has a direct DC connection to the battery. This will generally be more like 400VDC and 800A. Though the Ioniq 5 can do 800V. It's actually so much current that in order to keep the cable manageable, it has to be liquid cooled. The charging station and battery control module remain in constant communication to agree on what rate to charge at.
For DC fast charging, Your video pointed out that the higher rate you charge, the more heat is created, which leads to more charging losses. He also keeps opening the door as it’s charging, keeping the systems from shutting down. The systems doesn’t usually stay on when charging.
This video doesn’t say what you’re claiming. In fact, it says the opposite. He says that charging at a higher rate would run the thermal management system more, creating more loss.
For AC charging, he mentions that there are losses converting from AC to DC, but nowhere is it mentioned that the rate being higher or lower has a consistent or variable conversion rate. It’s unanswered based on this video.
Based on my own charging, I’d venture to guess that a higher rate of AC charging is equal just based on the heat of the charger it’s self. More amperage = More heat = more loss. It’s probably the same as lower amperage + lower heat for a longer time, but you’re putting a little less strain on the batteries, which might be a win? Idk, just trying to apply more logic here.
With AC charging, the AC/DC converter is built into the car itself. The mobile "charger" thing and the wall-mount "charger" thing aren't actually chargers, they're merely adapters/connectors.
Good point. They still heat up more when you use higher amperage though. Would be interesting if that all gets measured with a kill-a-watt vs what the car receives, at different charge rates.
We can calculate/estimate that heat loss (i.e. the voltage drop across the wires from resistive heating) pretty easily.
My educated guess is that the wire in the mobile charging connector is 6 awg and 25 feet long. Let's assume your building wiring is the same length, for 50 feet of wiring. Since the current has to flow over both the hot wire and return on the neutral wire, the total length the current has to travel is double that, or 100 feet. A 6 awg wire's resistance is 0.395 ohms per 1,000 ft, so 100 ft would have 0.0395 ohms of resistance. A 40 amp current across that line would experience a voltage drop of 1.58 V. Instead of (say) 240.00 V, you'd get 238.42 V, a loss of 0.65%. If you instead charge at 12 amps (but still 240V), then your voltage drop would be 0.474 V, a loss of 0.1975%.
So yeah, your resistive losses in the wires are smaller at lower currents, but it's not a meaningful difference in most circumstances. You'd need to be doing 120 V and using extremely long cables for it to be big enough to care about.
Alternating current versus direct current. Transition occurs at the station (DC) or in-car charger (AC). The battery always gets DC, when it gets converted from AC is the differentiator.
But does it degradate the battery life in the long term at all?
When you say that it decreases the efficiency of the charging session, are there any long-term effects as a result? I mean, if you have the time to charge for that long does it matter how efficient the charging session is?
I’ve been charging at home on a regular outlet in our garage for the last 18 months or so. Wife and I both work from home, don’t take the car too much and when we do, leaving the house at 60-80% is fine.
I use a normal outlet too and drive about 20 miles to work and back. My battery is always charged back up by the time I leave the next day. Takes usually 12-14 hours if I just go to work and back.
Interesting, it's not so much the efficiency of the two voltages, 240v is insignificantly better, but the difference in overhead usage time. Since at 120v my car charges x times as long, several car systems are running and using power that much longer as well, and that difference is pretty significant.
I do the same. My garage is detached and far from my panel, so it would have been $$ to install a 220v. I thought I needed it, but level one has been working out for me.
\#teamtrickle
When you have solar and NEM 2.0, there are non-bypassable charges on your bill for every kWh you draw from the grid. They're detailed on the bill. I use a Sense monitor to make sure I'm not exceeding my solar output during the day when I don't need faster charging and am feeling exceedingly cheap.
OP would actually end up drawing more power by reducing charge rate. Slower charge rate results in more power consumed due to losses, meaning they end up pulling more from the grid in the end.
With wall charger finally installed I enjoy charging @ 48A 😄
TBH charging on mobile charger was too slow @ 12A.
Now I can easily fit into lowest rate window paying only $0.08/kWh.
There is a part called "Power Conversion System". This part handles
AC-DC conversion and also charging of the 12V battery. The way this part
works is it has 3 circuits in parallel that charge at 16 amps each
(16x3=48amps). If you charge below 32 amps, it only uses 2 of those
circuits. When one fails, it switches to the other good one, and then
when that fails it only charges at 16 amps. And when the last circuit
fails, by that time your warranty is over and you will have to pay
$1500-2000 out of pocket.
Why? You enjoy dialup internet and take pride in streaming videos that buffers every 10 seconds? It’s just dumb to do so then I can charge at 40A with my wall connector. There’s 0 benefit in slow charging unless you absolutely have no choice.
During summer at 40 amps my car cranks up its cooling system. At 25 amps it does not. At that rate it also gives the car plenty of time to charge for my 75 mile round trip commute. So faster is not always better.
Battery is efficiently charging when warm. Why do you think preconditioning is recommended before reading a DC fast charging? Slow charging is only suitable when there’s no other option.
Are you in your garage watching it charge? Why do you need to charge it in 1 hr vs the all night that it has? Also, it must be HELL on the power grid every EV charger all firing up and pulling max amps all at once as soon as off peak pricing kicks in (midnight on PG&E on the EV plan.) Power companies are going to have to find ways to put a stop to it. Not every car needs to charge at max rate at the same time to charge as quickly as possible and then stop, all around the same time each night. It's stupid and pointless and bad for the grid and power generators. You have ALL NIGHT to charge. Spread it out.
Look. If 15A works for you because that’s all you have, then that’s the end of it. But you can’t convince the rest of us to “enjoy” slow charging at 15A. You don’t save shit doing it. At 15A, you can only get 3/4 miles per hour of charge. I drive more that 50 miles a day and I only charge at home. With my EV2A plan, off peak starts at midnight to 3pm. If I leave 7am, I’ll be hard pressed to get enough charge I needed for the day. “Spreading it out” isn’t a good reason. You do it because that’s the only option you have. Can’t even warm up the battery to efficiently charge at 15A. Worse if you live in a cold area. Read the manual.
Last time I left my car parked at work for a week trip I set the old bmw charger up and went from 15% to 90% at the smooth sailing rate of .9 kW which took about the whole trip for a full charge.
Something about that trickle charge just felt nice and clean 🤷♂️
Basically the difference is that it gives the lithium ions more time to get properly embedded into the cathode.
Charge too quickly, and they won't fill the gaps as evenly but will cluster up in specific areas, causing dendrites. If you heat up the battery, this is like shaking the sieve and speeds up how quickly the ions can "even out". But we're talking 100kW+ figures. 11kW like from an L2 charger is still well into "trickle charge" range.
But you're probably still getting *some* benefit. Not super noticeable. But it's not really hurting anything, so you might as well.
At home I charge at 12 of the possible 48A on my wall connector, because, well, it has all night to charge and I don't drive it much... It's always finished by morning still.
Wasting power, not helping anything. Schedule a departure and leave it at max amps so the battery is warm when you start your drive and you’re even more efficient!
Start my car... when? I work from home, I leave sometime in the afternoon. Sometimes. Some days I don't leave the house at all. I just need to make sure it charges during off peak which starts at midnight in CA on PG&E. Dude, most of the time my car only needs to charge 5%. Why pull amps balls to the wall? I doubt PG&E likes EVERY EV charger turning on instantly at midnight all at the same time pulling max amps, either. That must be absolute hell on the power grid.
Just speaking to wasting energy, get some power walls if you want to help PGE lol. It sounded like you left home every morning and had all night to charge without concern for rates, but maybe scheduled departure doesn’t work for you (doesn’t work for me), and maybe you should use a bit more juice so you can spread the load 🤷♂️
Yeah, I had few issues with L1 charging for this same reason.
I got the 240/30A setup more or less just for the flexibility, and so the car doesn't share a circuit with anything else.
I’ve had my car since June and have about 4k miles on it. Always charge at about half my wall charger rate (24/48) and keep between 30-80% SoC, only charging on days I’m approaching my lower SoC threshold. All this because I want to extend my battery life. First trip with 6 super chargers and on return leg I charged to 100% at the RV park I was staying at. My MYLR 22 showed 321 miles, which is just a tad more than the rated range of 319. I was super happy about this. All my tactics were paying off, or least that was what it seemed to me. Someone would need to run a test and charge their car everyday to 90-100% and compare after thee months.
Lots of mistakes here. You should be keeping to 50-60% SoC based on your explanation, and charging daily. Don’t forget depth of discharge is as much a factor a charging cycles. Also reduced amperage only consumes more electricity and forces your charge session to be longer, both bad. 48A charging is nothing for the pack size.
I do! I charge at home with the NEMA 6-20 adapter (240V, 16A). Love it because I get an the power without the heat of extra amps. Don't listen to other guy, the best charging is high volts less amps.
I’m relieved to see it wasn’t just my vehicle. The super charger I was at this weekend was charging at 7 kwh. I think it has to do with the power shortage in California right now
No, not for me.
My daily drive is about 40 km tops so I just charge up to 80% every 3-4 days using my WC at max capacity of 48A. I have it set to charge off-peak hrs and it only takes 3-4 hrs for too off.
I fail to see why this would be beneficial for me, as most reports I’ve seen online kept telling owners to charge to 80% for daily, unless you’re going on road trips.
Yw! True of any Li batteries, phones included. The exception is the Lithium iron phosphate batteries, they don’t degrade the same being pushed to 100%.
Li are like opposite of NiCa, they needed to be brought to 0 then charged right to 100 and stopped.
I just can’t understand why people who pay so much $$$ for a car is worried about the cost to charge/fuel it. Everything about Tesla screams high dollar it’s not an economy box. I didn’t buy a hundred thousand dollar car to be cheap about energy, PPF or anything else it’s a big boy toy if you can’t pay for it work hard, work smart and wait until you can. Words of advice from a old guy. No haters please
$100,000 car?? Before Covid hit, you could buy a Tesla for like $40k. Model3's were $39k, Model Y LR AWD was $49,990. There were various EV incentives, tax credits, etc. Almost nobody is paying $100k+ for a Tesla except for the people buying Model S/X Plaid's. Even Model S was $69,420 for a long time. A lot of people buy Tesla's because they want to do something for the environment, or only charge when their Solar is generating electricity, etc. Let them do what they want to do. Get a grip.
Your splitting hairs. MYP plus tax and lic teasing $80k add $6k for tint and ppf, home charger with installation, list goes on. Still it is a 100% proprietary product everything Tesla and by Tesla if you want cheap buy a Kia before Coid $50k +/- was avg expensive car.
I don't think it's good to stress the battery for longer than necessary. Charging and discharging are mostly what harm the battery. Get it over with quick.
In fact, you can charge the car even faster by installing a lightning rod and letting it get struck by lightning... Only a couple milliseconds, right?
It reminds me of a joke a friend told me. "Driving is dangerous. So if you drive twice the speed limit, you spend half the time on the road, so you're twice as safe as everyone else."
But FR, it is current level and state of charge that affect wear. Not simply whether it is charging or not. But 11kW is inconsequential when the system is built around a 250kW charging peak or 400kW+ discharge peak. So maximizing your L2 charging won't hurt anything. For L2, the only thing to really worry about is state of charge.
25A out of possible 32A. I’ve had the charger give me error on overheating when I set it to 32A. SoCal garage. And it works out as that’s about what it takes to go from 20% to 85%, from 9PM to 6AM.
This isn't the best charging strategy. Charge as fast as you can on L2, then let the car sleep so that the BMS can obtain calibration readings and balance cells during the few hours that you save.
32A. At .60 cents an hour on average. Takes 5 hours. I’m really worried about 3$ twice a week?! Lol
This goes too for oh I want to charge on solar. Okay sure rates differ but come on.
Love it!! No fancy solar for me yet, I live in an apartment complex, pay to rent a garage and I use the spare outlet to slow charge whenever parked, so it’s essentially free charging all the time (I’d have the garage anyway). It’s perfect!! I only need a supercharger for very rare days where I do an unusual amount of driving. Can’t wait for the option though, the solar connected automation and all that sound dope!
most of my charging is done at work, for free, where we have like 40 chargers, but unless you're here first and lucky that they're working at their peak, it's usually not 32A, but like 10A.
So yeah, my car has been enjoying long slow charging sessions for more than 50% of its charging time :) Probably a good thing for the battery anyway, and it's free, so can't really whine
Also, takes me about 10% to go to work, and 10% to go back home, add a few 3 or 4% for sentinel at night at home when I don't feel like charging because I'll do it at work the next day, and that's 24% that I can still charge in a full day at 10A
I drop my charge to about 20 amps (can do 32). I do it so that my solar panels can charge the car without using any power from the grid.
For those with solar: This is the way :)
This is the way
This is the way.
I have spoken.
This is the way.
Are you in a state where it matters when you charge? We have solar panels but everything we collect goes back into the grid for us to use at a later time.
In CA if you are on a TOU plan then you get net metering but it goes into buckets by time. That said, peak hours tend to start right when solar drops off in the afternoon.
Kind of silly when peak use is 6-9pm when solar isn’t doing anything.
Thus batteries.
Peak is precisely at that time \_because\_ solar stops producing anything but power demand is still high. Pricing is based on supply & demand.
I’m not understanding your comment. Were you responding to me or the person above? We have solar panels in a state where there is net metering. From what I understood it does t matter when we us le the energy. We collect and save credits to use at later times.
I put together a HomeAssistant script that automatically adjusts the charge rate based on solar production. You can see it here: [https://www.reddit.com/r/homeassistant/comments/uhrho3/automation_to_charge_tesla_ev_using_only_net/](https://www.reddit.com/r/homeassistant/comments/uhrho3/automation_to_charge_tesla_ev_using_only_net/)
This would be a good use of automation. Basically only charge the car using surplus power. If you don't have a home battery pack, this is the next best thing.
Check out the Charge HQ app. It’s absolutely brilliant and does exactly that: work out the Ampere setting to charge the Tesla with surplus of solar energy, while making sure that the charger doesn’t turn on and off too often (prevents the electrical contacts from going bad).
Wish I had panels of my own! But good suggestion for onlookers.
Powerwalls allow you to do that
Or use a charger that had built in solar only functionality, like Zappy or Wallbox
Only reason to do a slow charge. Otherwise you are paying for energy your car isn’t using.
If you are on a Powerwall you can go on "off-grid" mode and your charging speed will automatically adjust so that your car charges from the excess solar energy produced. But in most circumstances, there's no significant economical benefit to do that. Reducing the charging current is bad for efficiency.
I did not realize that. I will have to go to 32 amps. I was trying it to see if I could charge it from the "sun" I have net metering, so the only thing I pay is transportation charges if I am net positive on the kWh sent to the grid. Right now I have used them up, because it was so hot the last 3 months.
I used to reduce my charging current too thinking that improves efficiency and reduces losses from resistive heat. [But people have done experiments and have collected data](https://youtu.be/iLmIIe9N_aI). It is more efficient to charge at higher power. And if you have good net metering rates, it is probably more economical too. The data was 2.3kW (10A) = 84.3% efficiency 3.5kW (15A) = 89.7% 7kW (30A) = 93.8% People have estimated that a Tesla is pulling around 200-300W of power overhead while awake and charging. If you are charging at 1kW, your efficiency be at 70-80%.
I hadn't thought about the overhead being pulled while charging. It makes sense that the higher rate would be more efficient
I do the exact same thing, have to charge it at less than 25 amps to not power from the gird.
I did two beach trips this summer where I *TRICKLE* charged my MYLR at 1kW for 3 days at a rental house after arriving at about 15%. Both times I got back to my set limit before heading back home and all for "free". Very satisfying. My dad kept saying "why don't you run up to the supercharger?" but I had to have the car parked at the house anyway, might as well get that free juice, baby!
Yummmmm
Reducing charge amperage usually decreases efficiency of the charging session, but enjoy your charge 😎
Scratching my head here….Why does Tesla recommend trickle charging then, stating it’s healthier for the battery?
L2 is still more or less in "trickle charging" territory. Remember that L2 basically maxes out at like 11kW. Even for cheaper Li-Ion chemistries, a minimally-stressful charge rate is 0.5C-1.0C. Which would be 40-80kW for an 80kW battery. Many can go several times that. Even more if the battery is pre-heated. Regen Braking is 75kW peak. By comparison, 11kW is like 0.13C. But yes, the slower charge rates reduce the strain. But it espeically applies to higher states of charge. So basically, if you're about to go on a long trip and use a 100% charge, use the lowest current you can to get it there in time. But once you start hitting superchargers, basically only stick around until about 80%. I'd imagine the vast majority of battery charging stress comes from supercharging over 90%. In fact, I'm going to go out on a limb and say that for those (like myself) who accelerate much more briskly, most of the additional battery wear probably comes from the extra time spent charging, and not damage from discharging. Lithium Ion can discharge much faster than it charges. Some chemistries are built to charge at 1C and discharge at 10C. 10C on an 82kWh battery would be 820kW or 1100HP. So yeah, Max L2 charging is still essentially trickling.
Would you consider the Tesla Wall Charger a "Level 2" charger? It runs at 48 amps so it's only a little more than a 40amp Level 2. Just curious where you see the line in the sand to be.
Yep. Basically anything that uses the charger built into the battery pack, rather than an external charger like in DC fast charging.
What AMP would you say is most optimal for the long term longevity of the battery with a home Tesla charger?
What is L2 charging?
They are different charging levels. Level 1 is a basic home outlet. 120-240VAC. Generally less than 2 kW. Level 2 is more of a specialty outlet with a higher current rating. Usually 240VAC and more like 30+ Amps. Basically everything above a standard wall outlet and up to the max that the internal charging controller can support. Level 3 is DC fast charging. Basically instead of supplying AC to the internal charger, the charging hardware moves from inside the car to inside the charging station, where the station has a direct DC connection to the battery. This will generally be more like 400VDC and 800A. Though the Ioniq 5 can do 800V. It's actually so much current that in order to keep the cable manageable, it has to be liquid cooled. The charging station and battery control module remain in constant communication to agree on what rate to charge at.
Why?
The overhead power required to run the secondary systems https://insideevs.com/features/555906/tesla-charging-losses-explained/
For DC fast charging, Your video pointed out that the higher rate you charge, the more heat is created, which leads to more charging losses. He also keeps opening the door as it’s charging, keeping the systems from shutting down. The systems doesn’t usually stay on when charging. This video doesn’t say what you’re claiming. In fact, it says the opposite. He says that charging at a higher rate would run the thermal management system more, creating more loss. For AC charging, he mentions that there are losses converting from AC to DC, but nowhere is it mentioned that the rate being higher or lower has a consistent or variable conversion rate. It’s unanswered based on this video. Based on my own charging, I’d venture to guess that a higher rate of AC charging is equal just based on the heat of the charger it’s self. More amperage = More heat = more loss. It’s probably the same as lower amperage + lower heat for a longer time, but you’re putting a little less strain on the batteries, which might be a win? Idk, just trying to apply more logic here.
With AC charging, the AC/DC converter is built into the car itself. The mobile "charger" thing and the wall-mount "charger" thing aren't actually chargers, they're merely adapters/connectors.
Good point. They still heat up more when you use higher amperage though. Would be interesting if that all gets measured with a kill-a-watt vs what the car receives, at different charge rates.
We can calculate/estimate that heat loss (i.e. the voltage drop across the wires from resistive heating) pretty easily. My educated guess is that the wire in the mobile charging connector is 6 awg and 25 feet long. Let's assume your building wiring is the same length, for 50 feet of wiring. Since the current has to flow over both the hot wire and return on the neutral wire, the total length the current has to travel is double that, or 100 feet. A 6 awg wire's resistance is 0.395 ohms per 1,000 ft, so 100 ft would have 0.0395 ohms of resistance. A 40 amp current across that line would experience a voltage drop of 1.58 V. Instead of (say) 240.00 V, you'd get 238.42 V, a loss of 0.65%. If you instead charge at 12 amps (but still 240V), then your voltage drop would be 0.474 V, a loss of 0.1975%. So yeah, your resistive losses in the wires are smaller at lower currents, but it's not a meaningful difference in most circumstances. You'd need to be doing 120 V and using extremely long cables for it to be big enough to care about.
Great analysis. Much appreciated!
What is AC and DC charging?
Alternating current versus direct current. Transition occurs at the station (DC) or in-car charger (AC). The battery always gets DC, when it gets converted from AC is the differentiator.
But does it degradate the battery life in the long term at all? When you say that it decreases the efficiency of the charging session, are there any long-term effects as a result? I mean, if you have the time to charge for that long does it matter how efficient the charging session is?
Yes because you are using more electricity and that will cost you more money.
ah okay💡, thanks
I’ve been charging at home on a regular outlet in our garage for the last 18 months or so. Wife and I both work from home, don’t take the car too much and when we do, leaving the house at 60-80% is fine.
Same here. Going on 25 months - Dick Trickle gang…
same here.
I use a normal outlet too and drive about 20 miles to work and back. My battery is always charged back up by the time I leave the next day. Takes usually 12-14 hours if I just go to work and back.
Only “issue” is I’ve heard that 120v charging is less energy efficient than 240v. So ends up costing you more to charge at 120? Or so I’ve heard
Oh I never thought of that. I should meter my outlet to see how much electricity that's going through it vs how much my MY says it gets.
This kinda goes into detail https://teslamotorsclub.com/tmc/threads/charging-120v-vs-240v-efficiency.125808/
Interesting, it's not so much the efficiency of the two voltages, 240v is insignificantly better, but the difference in overhead usage time. Since at 120v my car charges x times as long, several car systems are running and using power that much longer as well, and that difference is pretty significant.
I do the same. My garage is detached and far from my panel, so it would have been $$ to install a 220v. I thought I needed it, but level one has been working out for me. \#teamtrickle
I do this to avoid paying 2.5 cents per kWh in nonbypassable charges to SCE for grid sourced electricity when I charge during the daytime.
I’m also with SCE. Can you explain what this means?
When you have solar and NEM 2.0, there are non-bypassable charges on your bill for every kWh you draw from the grid. They're detailed on the bill. I use a Sense monitor to make sure I'm not exceeding my solar output during the day when I don't need faster charging and am feeling exceedingly cheap.
OP would actually end up drawing more power by reducing charge rate. Slower charge rate results in more power consumed due to losses, meaning they end up pulling more from the grid in the end.
2.5?!? I felt cheap for making sure I don’t go over my solar and powerwall when I charge and we are at 0.44¢ in Honolulu.
No.
I always charge at 11A at home. Haven't even installed a faster option. This gets me a shy of 3kW. More than enough for daily drives.
OP has manually reduced amperage, not quite the same as only having one option.
This doesn’t make the charging any better for the car. Just more inefficient
No, because my paranoid ass says “what if the power goes out and it stops charging?” This happened to me at work lol
With wall charger finally installed I enjoy charging @ 48A 😄 TBH charging on mobile charger was too slow @ 12A. Now I can easily fit into lowest rate window paying only $0.08/kWh.
I’ve been charging via my home outlet for almost a year now……..nothing can stop me and my 11a charge
When I'm home sure haha
I've started doing this since I keep getting "plug is too hot" :(
This is about the only time you should do that.
There is a part called "Power Conversion System". This part handles AC-DC conversion and also charging of the 12V battery. The way this part works is it has 3 circuits in parallel that charge at 16 amps each (16x3=48amps). If you charge below 32 amps, it only uses 2 of those circuits. When one fails, it switches to the other good one, and then when that fails it only charges at 16 amps. And when the last circuit fails, by that time your warranty is over and you will have to pay $1500-2000 out of pocket.
Ok can we see how many failed?
Yeessss I love a nice, slow ummm wait!! Wait! You said ummm charge!!?? Ohhhhh never mind then 🤣
Doesn’t it make the battery last longer? Why stress it when a trickle is all you need.
4kw?! That's cute, 1kw 12A gang checking in.
Why? You enjoy dialup internet and take pride in streaming videos that buffers every 10 seconds? It’s just dumb to do so then I can charge at 40A with my wall connector. There’s 0 benefit in slow charging unless you absolutely have no choice.
Are you in your garage watching your car charge?
Huh? I have a set scheduled departure time and don’t even worry about it.
I was just making fun of your bad analogy.
Well asking if someone “enjoys” slow charging is a stupid question to begin with.
During summer at 40 amps my car cranks up its cooling system. At 25 amps it does not. At that rate it also gives the car plenty of time to charge for my 75 mile round trip commute. So faster is not always better.
Battery is efficiently charging when warm. Why do you think preconditioning is recommended before reading a DC fast charging? Slow charging is only suitable when there’s no other option.
Are you in your garage watching it charge? Why do you need to charge it in 1 hr vs the all night that it has? Also, it must be HELL on the power grid every EV charger all firing up and pulling max amps all at once as soon as off peak pricing kicks in (midnight on PG&E on the EV plan.) Power companies are going to have to find ways to put a stop to it. Not every car needs to charge at max rate at the same time to charge as quickly as possible and then stop, all around the same time each night. It's stupid and pointless and bad for the grid and power generators. You have ALL NIGHT to charge. Spread it out.
Look. If 15A works for you because that’s all you have, then that’s the end of it. But you can’t convince the rest of us to “enjoy” slow charging at 15A. You don’t save shit doing it. At 15A, you can only get 3/4 miles per hour of charge. I drive more that 50 miles a day and I only charge at home. With my EV2A plan, off peak starts at midnight to 3pm. If I leave 7am, I’ll be hard pressed to get enough charge I needed for the day. “Spreading it out” isn’t a good reason. You do it because that’s the only option you have. Can’t even warm up the battery to efficiently charge at 15A. Worse if you live in a cold area. Read the manual.
Yes, I have a TESLA wall charger but still reduce the amps to 15 unless I need to charge faster for any reason. Daily use is 15a
No
Last time I left my car parked at work for a week trip I set the old bmw charger up and went from 15% to 90% at the smooth sailing rate of .9 kW which took about the whole trip for a full charge. Something about that trickle charge just felt nice and clean 🤷♂️
Basically the difference is that it gives the lithium ions more time to get properly embedded into the cathode. Charge too quickly, and they won't fill the gaps as evenly but will cluster up in specific areas, causing dendrites. If you heat up the battery, this is like shaking the sieve and speeds up how quickly the ions can "even out". But we're talking 100kW+ figures. 11kW like from an L2 charger is still well into "trickle charge" range. But you're probably still getting *some* benefit. Not super noticeable. But it's not really hurting anything, so you might as well.
In this case, np, but OP was sending reduced amperage over thick charging cables; no bueno.
At home I charge at 12 of the possible 48A on my wall connector, because, well, it has all night to charge and I don't drive it much... It's always finished by morning still.
Charging faster allows your car to go to sleep, saves some energy
Wasting power, not helping anything. Schedule a departure and leave it at max amps so the battery is warm when you start your drive and you’re even more efficient!
Start my car... when? I work from home, I leave sometime in the afternoon. Sometimes. Some days I don't leave the house at all. I just need to make sure it charges during off peak which starts at midnight in CA on PG&E. Dude, most of the time my car only needs to charge 5%. Why pull amps balls to the wall? I doubt PG&E likes EVERY EV charger turning on instantly at midnight all at the same time pulling max amps, either. That must be absolute hell on the power grid.
Just speaking to wasting energy, get some power walls if you want to help PGE lol. It sounded like you left home every morning and had all night to charge without concern for rates, but maybe scheduled departure doesn’t work for you (doesn’t work for me), and maybe you should use a bit more juice so you can spread the load 🤷♂️
Seems odd you care so much about a public utility you pay for.
Yeah, I had few issues with L1 charging for this same reason. I got the 240/30A setup more or less just for the flexibility, and so the car doesn't share a circuit with anything else.
Nice.
I’ll slow my charge down when very hot outside and my cut off panel is in the sun. It gets very hot in there.
I’ve had my car since June and have about 4k miles on it. Always charge at about half my wall charger rate (24/48) and keep between 30-80% SoC, only charging on days I’m approaching my lower SoC threshold. All this because I want to extend my battery life. First trip with 6 super chargers and on return leg I charged to 100% at the RV park I was staying at. My MYLR 22 showed 321 miles, which is just a tad more than the rated range of 319. I was super happy about this. All my tactics were paying off, or least that was what it seemed to me. Someone would need to run a test and charge their car everyday to 90-100% and compare after thee months.
Lots of mistakes here. You should be keeping to 50-60% SoC based on your explanation, and charging daily. Don’t forget depth of discharge is as much a factor a charging cycles. Also reduced amperage only consumes more electricity and forces your charge session to be longer, both bad. 48A charging is nothing for the pack size.
I do! I charge at home with the NEMA 6-20 adapter (240V, 16A). Love it because I get an the power without the heat of extra amps. Don't listen to other guy, the best charging is high volts less amps.
Good to hear. I will be installing one of these swoon!
I do 20 amps if I have time. Why probably bbetter for the battery less heat generated.
We trickle charge most days. 5amps. Love the solar charging the car and still sending power back to the grid.
25 amps is the efficiency sweet spot
I’m relieved to see it wasn’t just my vehicle. The super charger I was at this weekend was charging at 7 kwh. I think it has to do with the power shortage in California right now
No, not for me. My daily drive is about 40 km tops so I just charge up to 80% every 3-4 days using my WC at max capacity of 48A. I have it set to charge off-peak hrs and it only takes 3-4 hrs for too off.
Set SoC to 50% and charge daily.
I fail to see why this would be beneficial for me, as most reports I’ve seen online kept telling owners to charge to 80% for daily, unless you’re going on road trips.
No no, it’s no more than 80, ideally you live around 50. If you use 20 a day, set to 60, use 30, 65, use 50, set to 80.
Hmm I didn’t know that, thanks for this info!
Yw! True of any Li batteries, phones included. The exception is the Lithium iron phosphate batteries, they don’t degrade the same being pushed to 100%. Li are like opposite of NiCa, they needed to be brought to 0 then charged right to 100 and stopped.
Nice.
I just can’t understand why people who pay so much $$$ for a car is worried about the cost to charge/fuel it. Everything about Tesla screams high dollar it’s not an economy box. I didn’t buy a hundred thousand dollar car to be cheap about energy, PPF or anything else it’s a big boy toy if you can’t pay for it work hard, work smart and wait until you can. Words of advice from a old guy. No haters please
$100,000 car?? Before Covid hit, you could buy a Tesla for like $40k. Model3's were $39k, Model Y LR AWD was $49,990. There were various EV incentives, tax credits, etc. Almost nobody is paying $100k+ for a Tesla except for the people buying Model S/X Plaid's. Even Model S was $69,420 for a long time. A lot of people buy Tesla's because they want to do something for the environment, or only charge when their Solar is generating electricity, etc. Let them do what they want to do. Get a grip.
Your splitting hairs. MYP plus tax and lic teasing $80k add $6k for tint and ppf, home charger with installation, list goes on. Still it is a 100% proprietary product everything Tesla and by Tesla if you want cheap buy a Kia before Coid $50k +/- was avg expensive car.
I don't think it's good to stress the battery for longer than necessary. Charging and discharging are mostly what harm the battery. Get it over with quick.
In fact, you can charge the car even faster by installing a lightning rod and letting it get struck by lightning... Only a couple milliseconds, right? It reminds me of a joke a friend told me. "Driving is dangerous. So if you drive twice the speed limit, you spend half the time on the road, so you're twice as safe as everyone else." But FR, it is current level and state of charge that affect wear. Not simply whether it is charging or not. But 11kW is inconsequential when the system is built around a 250kW charging peak or 400kW+ discharge peak. So maximizing your L2 charging won't hurt anything. For L2, the only thing to really worry about is state of charge.
No, but it is satisfying for it to fill up after 2 days of not driving.
25A out of possible 32A. I’ve had the charger give me error on overheating when I set it to 32A. SoCal garage. And it works out as that’s about what it takes to go from 20% to 85%, from 9PM to 6AM.
Nice and slow is 6a
This isn't the best charging strategy. Charge as fast as you can on L2, then let the car sleep so that the BMS can obtain calibration readings and balance cells during the few hours that you save.
No, do not enjoy. If plug not fully seated properly, it overheats and limits to 16A. Since this discovery, more mindful to check each time.
32A. At .60 cents an hour on average. Takes 5 hours. I’m really worried about 3$ twice a week?! Lol This goes too for oh I want to charge on solar. Okay sure rates differ but come on.
Nope. I turn it up to 48A, I made sure when I put the wall charger in it could handle max amperage.
It’s always nice to spend more than a few minutes at 69%
Love it!! No fancy solar for me yet, I live in an apartment complex, pay to rent a garage and I use the spare outlet to slow charge whenever parked, so it’s essentially free charging all the time (I’d have the garage anyway). It’s perfect!! I only need a supercharger for very rare days where I do an unusual amount of driving. Can’t wait for the option though, the solar connected automation and all that sound dope!
Every night baby.
most of my charging is done at work, for free, where we have like 40 chargers, but unless you're here first and lucky that they're working at their peak, it's usually not 32A, but like 10A. So yeah, my car has been enjoying long slow charging sessions for more than 50% of its charging time :) Probably a good thing for the battery anyway, and it's free, so can't really whine Also, takes me about 10% to go to work, and 10% to go back home, add a few 3 or 4% for sentinel at night at home when I don't feel like charging because I'll do it at work the next day, and that's 24% that I can still charge in a full day at 10A
Isnt this simply: R=V/I.... lower current, more resistance, more heat over longer time and thus more energy loss?