SOC Setting?

I set mine for 70%, and begin to charge to a higher level a few hours before setting out for driving based on what I expect. I use 90-95% if I expect a leg higher than 180 miles actual, but otherwise tend to use 85% on trips. All the advice I have had suggests that if you do use range charging, or any state above 80% you should begin driving within an hour or so of reaching the high charge state. Other people know lots more than I do about this though.

A big exception for me is the occasional time when I must leave my car off a charger for an extended period. I have done this twice so far. The last time I charged to 90% before leaving my car for a one month trip and the car was at 60% on return, exactly 1% per day drop. Thus in future I'll probably charge only to 80% if I must do that again. My temperatures were South Florida spring, typically 23-30 Celsius. This is not a good idea as a regular thing but I do notice that the CPO and other company owned teslae (that must be the correct plural of Tesla?) also are not regularly connected so I surmise that there is no major harm in this. battery aficionados will have more well informed opinions.

Yet another point. I do have some experience with fairly long legs, Savannah-St Augustine, for example. I have done that 170 mile leg with range charging once, with 55 miles left at arrival, and at 90% once with 40 miles at arrival. Driving at 75 mph most of the time I used 320 kwm both times. That seems probably better performance than promised. I do not have enough experience or data top trust that yet. I recently drove Charlotte-Santee, 168 miles, after doing a 30 minute demo ride with four people in Charlotte that has a surfeit of launches and assorted other power guzzling behaviour. I had range charged prior to leaving my hotel. I drove 80 mph or so most of the way with a couple bursts to much higher speeds. The total distance I drove on the leg was 205 miles and I still had 35 miles rated range at Santee. In short, my P85D, anyway, seems to do better than the books say.

So 70% daily charge takes care of everything I normally do without dropping below 30%, including interminable South Florida bad traffic and imprudent use of P85D power reserve.

Final point, maintaining lower SOC on my charger save money because i use free ones and Superchargers for anything trip-related. Why I am penurious about it when we pay the prices we do is a mystery, analogous to shopping for best gas price when one is driving a Maserati, but I did that too.

Sorry about the long-winded reply. I guessed more information might be better than less, even though i do not have a huge amount of experience.

When I picked up my car, I specifically asked this question and was explicitly told 90%. I asked if it would better if I didn't need that much to just charge to say 80% and they said there is no harm in just leaving it at 90%. Of course, they also let me know about how low and high SOCs negatively impact the battery if left for some time.

benjiejr said:

When I picked up my car, I specifically asked this question and was explicitly told 90%. I asked if it would better if I didn't need that much to just charge to say 80% and they said there is no harm in just leaving it at 90%.

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I was also told by Tesla service to keep it at 90%. They said that's what they were told in their training. I believe the only reason for this recommendation is to avoid range anxiety. I'm charging to 60% on week days.

Advice from Elon directly:

Mats Remman @cairnz
@elonmusk My daily commute takes about 50% SOC. What would be best for the battery long term.. 90%->40% charge daily, or 80%->30% ? (85kWh)
25 March 2014

Elon Musk @elonmusk
@cairnz 80% to 30%
25 March 2014

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Lower SOC is better for battery longevity, but the tradeoff is you can't go on a long trip on a moment's notice.

Indeed, but going from 80 to 90 takes how long? Half an hour?

I always use the default of 90% but I set the charge time to finish not long before i leave in the morning so it never really sits at that SOC for very long anyways ...

We set ours to 64%. Basically from what I've read it's best to keep it around 50% so we set it to 64% because she uses 14% for her commute to work. So while she's at work it's at 50%.

Poll is flawed. There is no 50% option. I keep mine at 50% most of the time.

I picked up 2 year/31k mile old CPO three weeks ago. When I got in the car, it was set to 85% and the specialist demoing the car to me swiped it to 90%, then swiped it to 100% (he knew I was driving long distance to get home). I presume the previous owner had it at 85%. Given the car charges to 239 miles @ 90% and 255 miles at 95%, it sounds like I would get the 265 new rated miles if I charged to 100%. I left it at 90% for the first week, but given that I charge at home using 120v, I never make it there. Once I started charging at work, I just set it to 85% figuring that if it worked for the previous owner, it will work for me. Either way, I am not fussing about it.

I didn't vote. My daily commute is short (20 miles roundtrip, so about 10%?), I'm thinking of keeping it at 60%...

Since the Chevy Volt runs from a low of 23% to a high of 88%, and I had good luck with that car, the sweet spot of the range mid-point seems to be centered on 55%, so I am using 80% and trying to not go below 35%. All evidence is anecdotal.

I keep mine mostly symmetrical on the high and low end SOCs. If I have a 50-mile day planned, I try to go from 70% to 50%. If I have a 100 mile day planned, I try to go from 80% to 40%.

- K

I keep it at 80 or 90. Then - if a long trip is planned (>300 km) I let it go towards 100 during breakfast, just before I leave. It usually 93-97 when I finally leave. So I never let it at a very high SOC for a long time.

Now we have a Supercharger in different directions from my home, between 50 and 120 km distance. So in the future I might just dial it down to 60 over night. I still like to top it off during breakfast, as I turn on the heating or cooling at that time.

Electricity is provided by my solar on the garage during the day

When I first got my car, the only options were something like Daily (I believe at or just over 90%) and Trip (100%). So I used Daily for quite a while before the slider became available. I started charging to 70% and ending my day at 30% most of last summer. I had heard it was better to play in the center of the battery's range. I was shocked to find that when I needed a full 100% charge that I was getting about 20 fewer miles than I used to get. I was down in miles at the 90% mark too. Common opinions were that either the battery cells were out of balance and/or the algorithm that calculates range was out because the battery hadn't seen a full to empty cycle in a while. I resumed charging to 90% and did see about 4 or 5 miles of range "return" but no more. FWIW, at about 48,000 miles, I get 244 Rated Miles at 100%, down from 265 when the car was new. Either I have about an 8% reduction due to battery degradation, or the battery's ability to properly calculate range is still out of calibration a bit. I had Tesla run a diagnostic at my last annual, and they told me the battery was normal and within specs.

mknox said:

When I first got my car, the only options were something like Daily (I believe at or just over 90%) and Trip (100%). So I used Daily for quite a while before the slider became available. I started charging to 70% and ending my day at 30% most of last summer. I had heard it was better to play in the center of the battery's range. I was shocked to find that when I needed a full 100% charge that I was getting about 20 fewer miles than I used to get. I was down in miles at the 90% mark too. Common opinions were that either the battery cells were out of balance and/or the algorithm that calculates range was out because the battery hadn't seen a full to empty cycle in a while. I resumed charging to 90% and did see about 4 or 5 miles of range "return" but no more. .

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So do you regret changing to 70% and wish you had stayed going to 90% or do you think that had nothing to do with it?

My local in-and-around-town travel requirements are met with a 70% charge that drops to about 45-50% by the end of the day. However, about 2-3 times a month, I'll charge to 90-100% for trips to Jacksonville or Orlando (or beyond). Then when I store it during my out-of-town/country trips which can vary from 2 to 6 weeks, I set the slider to 50% and drop the amperage to 10.

1208 said:

So do you regret changing to 70% and wish you had stayed going to 90% or do you think that had nothing to do with it?

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I'm not sure. Everything I read and hear tells me that operating the battery in the middle of it's range should, in theory, be better for its health and that the lower numbers I'm seeing are really just an anomaly of the way the car calculates its range. Charging it to a higher value daily probably contributes to better calibration. At the end of the day, it's probably not worth overthinking it. I think 100% is to be avoided and definitely the car should not be left sitting at 100% for any length of time, and 0 should also be avoided.

chriSharek said:

Also, could those of you who are only charging to 50-60% have bought the smaller battery vehicle and saved some $? Just thinking out loud here - don't get defensive!

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I need bigger battery almost every weekend and could use bigger than 85kWh because we have only 2 superchargers so far in Finland.