goneskiian
Active Member
K-MTG
Sunshade Captain of TMC
I am serious, it is actually set to 87%. I didn't want to got the full 90% so I thought 87% would be the best route to go?
goneskiian
Active Member
Which is fine but why post in the thread titled "What's your 90%?". Set it to 90% once, report what it is, change it back to 87%.
Why are you afraid of 90%? More second guessing of the Tesla recommended daily setting?
It's not safe to charge to 90% if you don't have the sunshade installed
K-MTG
Sunshade Captain of TMC
ernies
Member
My new 90% has dropped to 226. Interestingly it did the 1:00 a.m. charge and then started up again at 2:00 a.m. to charge again. Hmmm....
90% is a good, safe limit to charge to on a daily basis. You should only charge to 100% just before a long trip, and you should never leave it charged at 100% for an extended period of time.
And I agree to that. I am not sure if Teslas do any balancing (like the leaf does) at the end of a 100% cycle. If there was balancing, I want to think a 100% miles reported would be a more accurate estimate of battery capacity than the 90% number.
I plan to do 100% just before a long trip and right after a long trip to get back to the routine mode. And in the routine mode I would do a 100% once a week.
Welcome any other thoughts on this.
I would recommend charging to 100% only when you need to for a long trip. Maybe once or twice a year, if you notice that your rated miles isn't accurate, then try to charge to 100% prior to a decent trip in order to "reset" the algorithm to more accurately predict range (You may also need to drain the battery as low as you safely can, just as @aesculus will likely suggest in a few minutes). Otherwise, I highly recommend charging to 90% or lower on a regular basis. Don't worry about balancing, it's my understanding that the balancing happens on a regular basis, not only when charging to 100%.
Charging the top part of the battery generates a lot more heat in the cells and creates a reaction where a solid forms around the anode/cathode. This solid reduces the range of the battery. In fact, this is what happens in a brand new battery. A thin layer of solid forms around the anode/cathode, but it then insulates the terminal, preventing more solid from forming. Once that thin layer forms, you'll lose a tiny bit of range, but it should stabilize. It's only at higher voltages/temperatures (charging to 100% and leaving it there) that the thin layer will grow, thus further reducing the battery's range.
Charging the top part of the battery generates a lot more heat in the cells and creates a reaction where a solid forms around the anode/cathode. This solid reduces the range of the battery. In fact, this is what happens in a brand new battery. A thin layer of solid forms around the anode/cathode, but it then insulates the terminal, preventing more solid from forming. Once that thin layer forms, you'll lose a tiny bit of range, but it should stabilize. It's only at higher voltages/temperatures (charging to 100% and leaving it there) that the thin layer will grow, thus further reducing the battery's range.
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aesculus
Still Trying to Figure This All Out
I thought you needed to get the SOC as low as you could before charging to 100% for the range adjustment/recalibration.
Anyway once that is done then the 90% should be more accurate too.
Anyway once that is done then the 90% should be more accurate too.
Thanks for this info. I am curious to learn more on this.. share any good links if you have while I will also do my search on this topic.
Professor Jeff Dahn has a great lecture on why/how batteries die. Tesla will actually begin to collaborate with Professor Dahn later this month.
Starting to become concerned here. I've charged to max three times so far and my 90% dropped after each 100% charge event. 231->229->227. I've driven down to 25%-30% after each 100% charge and drove within a couple hours of completing the charge. Each 100% charge still hits 253. Is the 90% just a software estimate of past driving behavior or is it tied to actual capacity?
ohmman
Plaid-ish Moderator
It's a software estimate that could also reflect capacity. Sorry for the ambiguity. The likelihood, however, is that it's just the software estimate. That's what people have seen with the Model S. You can do a pack "rebalance" to get the estimate more reasonable, but since that doesn't change your actual capacity, I don't see a reason to go through the process.
After 3 weeks of ownership, mine (P90D) has always and consistently shown 231 at 90%. I have on two, maybe three, occasions seen 232.
I have power savings on and always connected as on. I lose about one mile to vampire drain every 20~30 hours.
I have power savings on and always connected as on. I lose about one mile to vampire drain every 20~30 hours.
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