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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health
- Thread starter KK_RedM3
- Start date
Great thread...Thanks much @gdgtgeek! I “use” the Stats app and have very little confidence in the stats it presents by virtue of the fact it chronically fails to record charge sessions. Out of 10 recent charge sessions at home only one or two showed up in the second page bar chart. It fails to log Supercharging sessions so how can anyone have any confidence in the efficiency numbers it displays?
Thanks for the heads up on Teslamate....I have to get it going....the data it collects and stats it produces look far more realistic IMHO!
Thanks for the heads up on Teslamate....I have to get it going....the data it collects and stats it produces look far more realistic IMHO!
ralph142
Member
I don't have any cool app graphs, but its clear from my weekly average wh/mi figures that once: 1.) the battery is cold, overnight temp 30-50 F, and 2.) I use the heater and defogging, my wh/mi goes up to 260-270 from 200 ish on the same daily commutes. so, roughly, 3000 wh during the summer to 4050 wh now. 33+% more. Translates into a home charging cost increase of 11 cents more a day (battery to wheels) tho so I not too worried. I warm the car up with the heater just before leaving and shift to seat heater and defogger on fan speed of 1, typically.
This week I started charging for the hour or so before I leave to see if warming the battery up has an impact.
MR, 18 areo, rwd, charging on a 120 v 15 amp circuit.
This week I started charging for the hour or so before I leave to see if warming the battery up has an impact.
MR, 18 areo, rwd, charging on a 120 v 15 amp circuit.
Amyshubby
Member
Does using the defogger warm the battery up differently (or better) than just turning on the heat?
ralph142
Member
I'm assuming that using the cabin heater doesn't heat the battery much, but that charging does. the defogger setting is just the ac directed to the windshield afaik.
scottf200
Well-Known Member
By chance I was looking at temp vs eff today. Using TeslaFI they have data for that. Drives --> Temperature Efficency: 'temperature' page URL link: TeslaFi.com Tesla Model S X 3 Data Logger
Yellow is an est(imate) for a Model 3 LR based on the relative losses I get on my X (My son has a LR Model 3).
I used the Wh/Mile at each temperature via TeslaFI to create a simple 'ratio' column compared to the Xs 'rated' Wh/Mile which I achieve in the 70-90s.
Hopefully the parenthesized note in the column header clarifies where that column's data came from).
Yellow is an est(imate) for a Model 3 LR based on the relative losses I get on my X (My son has a LR Model 3).
I used the Wh/Mile at each temperature via TeslaFI to create a simple 'ratio' column compared to the Xs 'rated' Wh/Mile which I achieve in the 70-90s.
Hopefully the parenthesized note in the column header clarifies where that column's data came from).
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scottf200
Well-Known Member
I realized my son and I have access to each others TeslaFI.COM so I grabbed his current data. He is a little more south than me so gets milder weather.
Data on the *right* of the black line is *actual* 2018 Model 3 LR data.
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Dariushd
Member
Just hit 240 at this time at 80% charge coming up from 18%. A total loss so far of 12 from its peak. The degradation continues at about the same pace so far.
My charge strategy is to 80% with a couple times to 100%. Sometimes I plug in daily sometimes I go a couple to a few days before charge. One poster suggested switching it up to charging to 90% for a while. I’ll try it, why not. I’ve spoken to a few Tesla service folks and there is absolutely no typical answer from anyone. What’s the best way to track this stuff, TeslaFi or something as opposed to be just posting numbers occasionally here?
My charge strategy is to 80% with a couple times to 100%. Sometimes I plug in daily sometimes I go a couple to a few days before charge. One poster suggested switching it up to charging to 90% for a while. I’ll try it, why not. I’ve spoken to a few Tesla service folks and there is absolutely no typical answer from anyone. What’s the best way to track this stuff, TeslaFi or something as opposed to be just posting numbers occasionally here?
I’ve had teslafi for my S. Just added the 3 - should have done it earlier to have the record.
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Mentioned this in the performance degradation thread but figured I’d add it to the master thread. There’s a lot of talk regarding real vs imagined battery degradation, bms miscalculations and suggestions on how to prevent that. For those that only drive 40miles/day and only use up 15-20% of battery a day, it seems the best way to prevent BMS miscalculation is to not charge every day, use more of the battery and don’t short charge. But could we be screwing ourselves in the end? Was reading Tesla warranty info and noticed this. “See your owner documentation for important information on how to maximize the life and capacity of the Battery, failure to follow these recommended battery maintenance and charging procedures shall void this Battery and Drive Unit Limited Warranty.” Tesla recommends keeping it plugged in and is pretty much the only part of the battery section in the manual that’s capitalized and bolded. “Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it.“ So instead of worrying about bms miscalculation should we just plug in everyday? even if you only drop a couple percent or risk Tesla screwing us for potential warranty replacements If we don’t?
Allistah
Member
Interesting thought about leaving it plugged in all the time. I think there is a lot of information around these things and I'm hell bent on figuring this out a bit. We travel around 120-140 miles every weekday so I have to plug in every night. I'm going to go back to 90%. I started setting it lower to 85%, then 70% but I don't think that was a good idea based on the knowledge I've read about letting the battery balance itself. Who knows if that's right or not, people argue about that too. lol
Pavlo_Y
Member
Mine shows the same! It started right after I had drained battery to about 7%.
Feb 2019 build M3 LR AWD
Allistah
Member
I'm just sharing a thought that I think would be cool if we could get to this point. If we could figure out what a "best practice" is of sorts for charging that would really help combat the range loss that people see. For example, our car gets driven about 120-150 miles every day. I was lost in what the right "charge to" point was. I started at 90% since that was the default, then lowered it to 85, then 75, thinking I was doing the right thing. All the while I rarely if ever ran it up to 100%. Maybe only twice in almost 6 months. Now the range has been extended so our range loss is around 10% (322 max and we currently have 189).
Since we drive the car quite a bit, it would be cool if we could come up with some sort of starting point for a recommended charge schedule that would help people keep their ranges high and that would be good for the battery. You could also say to just drive it, but what fun is that? We have such an incredible piece of technology to work with - it would be really cool if we had almost like "Recommended Charging Profiles" that people could use as starting points if they drive x or y amount of miles a day that would give them best practices for the battery and also to help them keep up their max ranges opened up to where they should be. I'm currently in the process of figuring this out for our car and if I get anywhere with it, I'm going to share that schedule. If you drive between x and y miles a day, start with this schedule, if you drive between v and w miles a day, start with this schedule. I don't know, just thinking our loud. I'm excited at what I may learn about our car. Thanks for listening to me rant about this stuff.
Since we drive the car quite a bit, it would be cool if we could come up with some sort of starting point for a recommended charge schedule that would help people keep their ranges high and that would be good for the battery. You could also say to just drive it, but what fun is that? We have such an incredible piece of technology to work with - it would be really cool if we had almost like "Recommended Charging Profiles" that people could use as starting points if they drive x or y amount of miles a day that would give them best practices for the battery and also to help them keep up their max ranges opened up to where they should be. I'm currently in the process of figuring this out for our car and if I get anywhere with it, I'm going to share that schedule. If you drive between x and y miles a day, start with this schedule, if you drive between v and w miles a day, start with this schedule. I don't know, just thinking our loud. I'm excited at what I may learn about our car. Thanks for listening to me rant about this stuff.
I have 2018 M3D long range, only getting about 300 miles at 100%. Tesla said batteries are good. I only drive about 30-40 miles per day (retired). I charge every night to between 50 and 80%. Car sits in unheated Minnesota garage over winter undriven but plugged in charging to 80% for several months. Is this affecting charge capacity? What should I be doing differently?
Allistah
Member
Based on everything that I've read over the past week, it appears that you should charge to 90%, always, and keep it plugged in. Someone even asked "What if I just drive around the block or other short distance?" The answer was to still plug it in at 90% every night anyways.
Seems like that is the standard number now. I was going lower, which was fine for the battery but I guess what that can do is leads to further reported loss of max miles when at 100%. From what I understand, the more you keep the batter in the middle, the more it loses touch with where the top and bottom of the battery is and has a hard time giving a more accurate max range type of thing. Hope that makes sense. I've since switched back to 90% and have done a couple 100% runs so I'm going to work with it over the next couple weeks to see if I can get it back up to max range. It doesn't suddenly just go back to max range (which is 322 for me now), it happens over time from what I've read in these forums. The fact that it's a slow mover back to max range is why it trips people up - I think people charge once or twice to 100% and then it doesn't do anything and they think it doesn't work. I'm not convinced.. I think it takes a couple weeks of doing a schedule of charges with a couple 100% charges happening once a week or something while charging to 90% the rest of the time. I don't know, just my own theories at this point. I'm working on it with our own car so we will see what I can do with it.
I doubt going to 90% is going to fix anything for you. Based on this chart (which I pulled from someone else's post), I think going down to a SOC lower than 50% and charging up relatively high will be more likely to help, because that will give the BMS a larger voltage difference to work with.
I have very little data to back this up, but I think the general recommendation should be:
- Center your typical use around 60% to maximize battery longevity, if possible.
- 1+ times per month, include a charge session from <40% to >90% for BMS calibration.
- Never let the battery sit at > 90%, especially in hot weather.
Allistah
Member
The problem is that trying these things takes so much time that people often give up and say it doesn't work, etc. I think it will take a few weeks to get things fixed for people and finding out a solution could take a long time. I'm willing to stick with it, I think it's important - but again, takes a lot of time. I've done my two 100% runs at home already and am now charging to 90%. Only on the first day so at the end of the week I'm planning on stopping at a SuperCharger and going to 100% there and then doing it again in another week with 90% charges at home. Will see what happens..
I'd also love to find out some information around this whole "anything above 93% kicks in the BMS calibration". If that's the case, would be interesting to charge to 95% for a few nights and see what that does. Lots of questions! lol
So if lettingtthe battery drop below 50% and charging to 90% nightly is recommended, what does someone who only drives 30-50 miles a day do? Do they let it go without charging for a few days until the battery % drops below 50%? Or do they just plug it in and charge to 90% every night no matter what the charge level dropped to?
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