Charging 220v or 110

[Saghost]

Okay, case closed. 120/240 it is. I think we all agree by now. Now back to my important question concerning VW eGolfs.

But I don’t have your answer.

I’m sure that in general there’s some overhead and the same principle should apply, but without active thermal management the overhead might be a lot smaller - and there could be an advantage to slower charging in hot weather, since it’ll let the pack stay cooler.

 

[user212_nr]

But I don’t have your answer.

I’m sure that in general there’s some overhead and the same principle should apply, but without active thermal management the overhead might be a lot smaller - and there could be an advantage to slower charging in hot weather, since it’ll let the pack stay cooler.

So which is better 220 or 120v?

 

[Saghost]

So which is better 220 or 120v?

220, 221, Whatever it takes.

For a Tesla, 240V is always better if it’s conveniently available.

I’m not sure that’s true for the eGolf in hotter weather, though.

 

[user212_nr]

220, 221, Whatever it takes.

I was kidding (by saying 220). 22 replies just because someone said "220 vs 110" in the title. I thought I'd pile on.

I don't understand why the discussion when its a simple typo/misunderstanding. This must not be the first time someone not familiar with electricity said 220v.

 

[nvx1977]

I ended up going the DIY route when installing my 14-50 circuit. My electrical experience before that was fairly low. I will say I was initially confused when starting my electrical education on youtube why some sites were referencing 110 vs 120 and 220 vs 240. I thought there must be a difference.

Turns out, nope. 110 and 220 are holdouts from old times, and as is typical in trade work, many people just say and do things because "that's how it's always been done". In software development, we call that cargo cult programming.

Me, I prefer to be accurate and remove ambiguity wherever possible, so I've always made it a point to say 120V and 240V, because that's the ACTUAL voltage (what a concept).

 

[08micev]

I charge my model 3 all time on a nema 5-20. 110/120v Works great!

 

[08micev]

-

 

[Dmagyar]

I traveled about 30 to 40 miles a day except for Saturday. Saturday probably 100 miles. Questions is what is the best alternative to charge my car. Charge my car Monday to Saturday to 90% using 110v and crank it up 100% on Sunday using the 220v or charge 90% up 3 times a week using the 220 volt?

Pretty sure that it's been 120/240 volts now for some time...catch up, please...

 

[jamnmon66]

Are you saying what is better for your battery or what is better for your lifestyle?

I don’t believe there is any issue with battery health with charging at 240v. The max you’ll do on the SR+ is 32 amp, so approx 7.6kW. As far as I know that’s entirely safe for the longevity of the battery. Keeping the charge somewhere between 70-80% is going to do a lot more for your battery health then ~1.4kW (120 volt 12amps) charging.

On a SR+ 70% should get you ~170 mi. Even with aggressive city street driving or cold weather you should be able to get 90 to 100 miles out of that.

So, probably get a 50 amp NEMA 14-50 installed and just use the standard mobile charger that comes with the car and plug it in every night with your charge limit set to approx 70%. Maybe bump it to 80 or 85% if there is snow on the ground or you’re in sub freezing temperatures. If you really wanted you could just charge every other or third day, but the vast majority of people just plug in every night.

Edit: To compare, if you’re worried about frequent supercharging events causing Tesla to throttle battery charging speed, that’s fairly rare AND when they do throttle it, it’s usually still 50-60kW or more. Max supercharging rate on SR+ is 100kW. So your “fast” home charging is less than 10% as fast as Tesla allows the battery to charge, and still ~15% as fast as Tesla allows a throttled battery to charge!

Plug in using the 240 every night if you can. A plugged in Tesla is a happy Tesla. Then systems can use wall power instead of flexing on your battery during the Plugged In Time.
For battery health having your battery spend most of its existence charged at or near 50% is best.

So, if you use about 20% capacity on any weekday. Charge to 70 or even 60 those days. That means most of the time your battery will be between the 40%-60% range. That's perfect for battery health. If you use 30-40% battery during a normal day then I would charge a bit higher to 70%. Which means your battery will spend most most of the time between 30 and 70%.

Still, I would bet that most of us are guilty of over charging our batteries. I am too but I always think to myself... I might have to drive somewhere, far and unexpectedly. But realistically how often does that happen.
However...
If you do typically unexpectedly travel I recommend gauging that in and charging extra for that.

Going below 20% can be very hard on the battery. Worse than being charged to over 80%.
The big reason for that is there are controls on how much charge a full battery or nearly full battery can take. Overcharging a full battery or charging it too quickly is bad for it . Also discharging a low battery aggressively is bad for it .... and there are less of controls on how aggressivly you can discharge a low battery. And by discharge I mean stomping on it and taking off.
Basically they want you to have full power when you stomp on the accelerator pedal at all battery ranges.

RandomX

Wish there was a way to vote best answer. These are the two best answers to the OPs post.

 

[Chetopalka@gma]

How much charging will it take for the inefficiency to cost more than the cost of the 240v install?

Thanks. So, I am curious to know how much it would cost in dollars, for example, to charge on 120 vs 240 to get 100 miles. Is the electricity consumption in watts the same or not? I have 2 Teslas and use both and I'm curious to know if I am wasting juice with the lower voltage charging. I don't want to do the math and not be sure that I am doing it correctly.

 

[RayK]

Thanks. So, I am curious to know how much it would cost in dollars, for example, to charge on 120 vs 240 to get 100 miles. Is the electricity consumption in watts the same or not? I have 2 Teslas and use both and I'm curious to know if I am wasting juice with the lower voltage charging. I don't want to do the math and not be sure that I am doing it correctly.

Note that I do not charge at home, so my answer is based on what I know / read here.

Charging at 120V is more wasteful than at 240V, from the perspective of getting electrons into the battery. There's a certain amount of overhead (current) that the car takes up and using 120V charging means that a higher portion of the supply goes there instead of the main battery. From the amount of power that's consumed, I'd say that charging at 120V is going to be slightly more than 240V mainly because it will take more time to get to your charge limit.

If you really want to know exactly how much energy is being used, you'll have to install a good (and accurate) power meter.