-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
What should my ideal charge percentage be?
- Thread starter Al Sherman
- Start date
Three60guy
Member
As I read this thread, I too wondered about the software limited charging condition of a battery. I have a software limited 70D in a physical 75KW battery. When I charge to 100% my battery actually only charges to a maximum of 93%. This magic number appears to be the one mentioned which turns on battery balancing. Hmmm. So, how well does that work? Does it actually work? Do we, as some have told me, have to bring it in to Tesla Service to actually get a true battery balance once a year?
My take on what I have read is I have "less" to worry about because I would never reach 100% of my battery ever unless I purchase the extra 5KW option for over $3000. To me that isn't a good choice. What do the experts think here? Does a software limited charge hurt my battery over the long term because I can not reach true battery balancing? Am I wrong to conclude that a software limited 70D is actually a good thing to really hang on to over the long term because I will never reach that dreaded high rate of charge of 100%? Should I conclude that I need to follow the exact same protocol when charging my battery compared to those who do not have a software limited battery?
These are real concerns. Many have this type of battery when you consider those who have a 70D and now 60D software limited battery Teslas. For my money, the answer to how to properly charge your battery is one of the most important aspects of Tesla ownership. I learned this when I was a Prius owner and learned that Toyota limited the range of battery use as well. So, the idea of limiting the range of charging between low and high states has been pounded into my head for 10 years. My first Prius was in 2006. So, I totally understand how important the idea of "proper" charging is. But after I purchased my Tesla S70D I also understood that the fine art of proper charging was going to be potentially different than for those who did not have a software limited version. I just have not concluded I have the final answer. That is why I read with interest this thread.
I hope the "experts" are still reading this thread. I hope they shed their insights for those of us with this kind of Tesla battery system.
Cheers
I have one of the last 85Ds with about 11,000 miles now. I have done 2 range charges in the car's life (one to 100% and one to about 97%.) Most days I only charge to 50% and when it is really hot, I keep it between 20 and 40%, except when I need more. I am ashamed to admit it, but as one funny post said I breastfeed my battery.
I have never seen the battery "out of balance". I have the Visible Tesla software, and I consistently get the equivalent of 275.2 miles on a full charge or the appropriate fraction. For example, when I do a 50% charge I always get 137.6 miles, which is exactly half of 275.2. I don't know if this was something on the early cars, but again, I have never seen where my battery gets a different range at the same charge percent.
I have never seen the battery "out of balance". I have the Visible Tesla software, and I consistently get the equivalent of 275.2 miles on a full charge or the appropriate fraction. For example, when I do a 50% charge I always get 137.6 miles, which is exactly half of 275.2. I don't know if this was something on the early cars, but again, I have never seen where my battery gets a different range at the same charge percent.
50% on a daily basis will throw the pack out of balance and it will appear that you have lost a lot of range. 90% does no harm based on the many posts in this group. Neither does the occasional 100% charge--just don't leave it sit at 100%. The 50% is really for long periods when you're not driving the car.
All you need to do is resume charging at 90% and it slowly go back into balance. A 100% charger will rebalance the pack faster, but it's only suggested that you charge to 100% if you anticipate needing all the range and don't leave it at 100% for too long.
The procedure I use is running it down to 10% then a full 100% charge. The balancing kicks in around 93%.
The balancing circuits activate at 93%, so just charge to more than that. Once activated they will stay activated until complete regardless of charge level or trip length. (WK057 did a lot of research and experimentation to find this out). My experience is that it takes several cycles to regain the "missing" miles.
I have a question related to this thread. Regarding the 60 kWh option, it basically is the same battery hardware as the 75 kWh, but has limited range on a software level. Does this mean that 60kWh users should always charge to 100% since it's already at 80% when it's 60 kWh? Has anyone thought about this?
AustroTom
Member
We just got our S60 about 6 weeks ago (2,800 miles so far), and we were told by a service technician and sales staff that it is ok to charge the 60 to 100% pretty much always, as the last 15KW are dormant.
So that's what we do, (unless somebody comes along and refutes this claim
)
So that's what we do, (unless somebody comes along and refutes this claim
)
roblab
Active Member
Since we don't need to charge to full, I charge to 90%. Since the car limits charging speed somewhat severely as the battery fills up, it seems obvious that it doesn't like full charge. The car also tells you that charging over 90% is for trips. I guess you can fill to 100% allatime, but since the battery is the most important and expensive part of the entire car, most Tesla owners try to be gentle with it. Many people who buy a used Tesla from an individual want to make sure the battery has been babied.
Roblab, you're talking apples and oranges. Your 90 has a 90 kWh battery so you appropriately avoid charging it to 100% except for trips. AustroTom's 60 has a 75kWh battery. When he charges to 100% it's really only 80% of the full battery. If and when he pays to unlock the full 75kWh, then he'll want to only charge to 90% too.
My 2 cents. I read through this thread and many others and there are many different opinions. I emailed my service guy at Tesla and his response was, "plug in nightly if possible, full charge isn't a problem on occasion - charge to 80% for daily driving when range is not needed."
I know that is one tech's opinion that works for Tesla and others may say different. However, that sounds reasonable to me so that's what I'm going with.
I know that is one tech's opinion that works for Tesla and others may say different. However, that sounds reasonable to me so that's what I'm going with.
AustroTom
Member
Again, are you referring to software locked batteries (60/75KWH), or full battery range vehicles?
whttiger25
Member
We just got our S60 about 6 weeks ago (2,800 miles so far), and we were told by a service technician and sales staff that it is ok to charge the 60 to 100% pretty much always, as the last 15KW are dormant.
So that's what we do, (unless somebody comes along and refutes this claim
The easiest way to determine if 100% SOC in a new 60 is really 100% or 80% (i.e. if the dormant end of the battery is on the top or bottom) is to look at the rate of charge at a supercharger as you approach 100%. If it is higher, i.e. 15-20kw, then there is definitely a lot of room above the 100% SOC. If it slows to a crawl, then you are at the battery's true 100%.
I'm sure this has been tested by someone but searching the forum is sometimes harder than just getting an answer from someone willing to reply quickly, or if you have actually used a supercharger to charge to 100% and have anecdotal evidence.
I suppose it is also possible the dormant end is split between the top and bottom. That would be odd but possible. Anyway, the max rate of charge the battery is taking as it hits 100% is useful info and one could look at charge rate curves (charge rate vs SOC%) for the 75 battery to determine how exactly the dormant portion is allocated.
Similar threads
