I have a refreshed 70D, i.e., a 75kW battery...does that allow charging to a slightly higher level than one would have on a pre-refresh 70D, while having the same impact on battery health? In other words, is charging to 86% on a refreshed 70D the same, battery-health-wise, as charging to 80% on a pre-refresh 70D?
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I have a refreshed 70D, i.e., a 75kW battery...does that allow charging to a slightly higher level than one would have on a pre-refresh 70D, while having the same impact on battery health? In other words, is charging to 86% on a refreshed 70D the same, battery-health-wise, as charging to 80% on a pre-refresh 70D?
A 100% charge might be good for recalibration of what the car thinks it's range is, but I believe you only need to hit 93% to activate the balancing bleeders.
Really, it's just that simple. The liquid cooling keeps the cells from overheating. The small size of the cells means that they keep a more even temperature than the large cells used in some EVs. I wouldn't worry too much about the 93%. Generally, you'll do it often enough when you take trips.
I'd just set it to the maximum daily range and not worry about it. It's diminishing returns. The amount of life you save by going lower diminishes as you go lower. e.g. There's a big difference from 100% to 90%, a small difference between 90% and 80%, an even smaller difference between 80% and 70% and so on. I don't know that anyone outside Tesla knows the actual amounts (as best I can tell, I'm down about 3% in three years and over 70K miles).
If you're going to store it for a long time (I'd suggest long time = minimum eight weeks) then set the slider to the lowest position and keep it plugged in. Some folks like to plug it into 110V for long term storage, but I doubt that's necessary.
GlmnAlyAirCar
Active Member
This is not true to my knowledge. 1 cycle (0 to 100% to 0%) is equivalent to 60%-70%-60% 10 times. There are reasons to avoid the top (and probably bottom) 10%, but that is another issue.
GlmnAlyAirCar
Active Member
AZ Desert Driver
Rare combination
I charge to 100% every month or two to both balance and recalibrate the algorithm. I was told by a Tesla engineer this was best for my particular battery pack. Also, although I plug in every night I don't recharge to 90% until I'm between 50%-60% SOC. I've been following this process for about 3 months with very good results.
HankLloydRight
No Roads
I set the daily charge for 50% which allows me to plug in daily without kicking off the charger. When I see it go below 60% I reset the charge limit to 90% so it will do a scheduled recharge that night. That means I charge maybe once or twice a week.
Johan
Ex got M3 in the divorce, waiting for EU Model Y!
Why do you plug in when you are above your charge limit? In case the vampire drain works up an unexpectedly high apetite that night?!?
I always thought that "a plugged in Tesla is a happy Tesla" and wouldn't the car be pulling from the 12 volt if it was not plugged in? Not too worried about massive vampire drain. If none of that is true then I wouldn't plug in every night.
Johan
Ex got M3 in the divorce, waiting for EU Model Y!
I'm 99% sure it doesn't charge the 12V battery from the wall socket, only from the big battery and only when the contactor is enganged which is, I believe, during 1) driving and 2) charging (of the big battery). So in other words you plugging in the car to the wall socket when you are above your set charge limited accomplishes nothing. The only two instances where it would turn out smart to do this is:
1) You realize at night that you will need a 90% or 100% charge the next day, through the remote app you bump up the charge limit and the car starts charging (without the need for you to go to the garage to physically plug in)
2) Something happens and you need to suddenly leave, leaving the car unattended for a long time, during which the vampire drain eventually makes you reach your charge limit.
HankLloydRight
No Roads
This is what I was getting at with the plugging-in-but-not-charging routine. I would add a third scenario, though: If you want to pre-heat or pre-cool the car before departure, that would better be served from the house power and not the main battery.
12V circuits always pull power from the 12V battery. The DC-DC convertor tuns on every few hours to recharge the battery from the main bus. The rest of the car always pulls power off the main bus. To feed in power from the wall, that power runs through the charger into the main bus, which will also turn on every x hours, depending on how much vampire draw you have. That could be a day, or a week, etc.
This is why the 12V batteries die so often.
HankLloydRight
No Roads
Ok, this doesn't make sense to me (not that it doesn't make sense at all, just doesn't to me), but this seems like overkill. If you are plugging in every night anyway, I would just set the charge to 70% or 80% and leave it at that all the time -- except when I need to do a range charge for a long trip.
I leave mine set to 70% most of the time, and plug in every day.. some days it charges for 30 minutes, other days maybe an hour or three depending on how much driving I've done the day or two before (yes, sometimes I forget to plug in and it doesn't charge that night).
I'm not sure I see the logic is resetting it to 90% once a week just so it doesn't "charge every day". When Tesla said "a plugged in Tesla is a happy Tesla" I think that's what they meant -- that recharging to a set % every night is OK.
Canuck
Well-Known Member
Where did you speak to a Tesla engineer? I find this alleged advice very odd since anyone with a basic knowledge of how lithium ion batteries work would never say cramming in electrons is good for the cathode in a lithium ion battery. It makes no sense since the more electrons you put into a lithium ion battery (after about 80% especially), the more the cathode degrades. Now, I know Tesla's 100% is not each individual cell battery's actual 100%, but it's high enough that Tesla tells you not to go past their 90% unless needed for range. They say that because high charge levels hasten capacity loss.[88]
How can you know good results after 3 months? It takes longer than that to start to notice cathode degradation. That like saying my three year old child is nice and healthy and will live a long life even though I feed him McDonald's every day.
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I agree the plugging in and not charging routine doesn't make sense and it isn't best for the battery. If you only do enough driving every day to knock off 7% of your charge, then set the charge to 60% and leave it there and plug in every night. You'll go from 60 to 53% daily and back up to 60 every night when you charge. This is better for the battery than exercising 40% of it's range weekly plus it's better to not charge to 90% unless you have to. Yes 100% is WAY worse than 90% but 60% is still better than 90% as long as you don't need to dip too low.
Also, say you do 4 cycles of 50 to 60% over 4 days(i.e. 1 10% range cycle per day). This is better for the battery than 1 40% range cycle every 4 days.
FYI, the 90 cells are identical in size to the 85 cells. The reason they have more capacity(5kw) is because there is some silicon on the anode which allows the anode to absorb more lithium ions than the carbon only based anode. As such, the silicon infused anode will physically expand more in size than the carbon only anode which means if you charge the 90 kWh battery to 100%, you are physically deforming the inside more than charging the 85 to 100%. Anode fracturing occurs from changing the size. This is why smaller more frequent cycles that add up to a range of x% are better than 1 single cycle that adds up to x%.
