Well my car was service over the weekend. The fine people at the Atlanta Service Center had it plugged into a 110. I could tell on my tesla app. I had been stuck on 236/237 rated range for a month or so. On the 110 it magically charged to 242. When I got it home I plugged it into my 14-50 outlet and it charged to 242. I wonder if the long 48 hour charge on the 110 conditioned the battery. It too about 48 hours to charge from where it was at.
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deonb
Active Member
My 236/237 were not "vampired." I have charged mid-day and that's what I was getting. It will be interesting to see what I get tomorrow morning off my own 14-50.
FalconNinetyD
Active Member
After 5000 miles, I typically see 237 or 238 in the morning, charging off of a NEMA 14-50. I'm out of town, and have had the car on a 120 outlet for the past four days. I'll check the range via my phone app in the morning. I assume it tops off based on the scheduled charging? We're on the east coast this week, with the car on the west coast, so if I check it when I wake, it shouldn't have too much vampire drain.
islandbayy
Active Member
Having worked with other non-vehicle lithium batteries, I will say in many cases a slow charge can provide more charge.
What happens in my opinion, is with a quicker higher capacity charge, the "surface charge" (Higher Voltage reading due to the electricity not being absorbed quick enough into the battery) can result in a pre-mature shutdown of the charger, and a poorer reading of total state of charge.
This is seen more with older lead acid batteries, but the larger the pack, the more noticeable it is.
I can use a Lead Acid battery as a example.
Car battery is "12 volts". Fully charged their about 12.8-13.2 volts depending on the specific type (flooded, Gel, AGM). Now, put it on a automatic charger (or any 12v charger for that matter), when that charger shuts off that the battery is full, the immediate reading is much higher then the normal maximum of 13.2. It could be as high as 15 volts for a short while.
This higher voltage trips the "I'm Full" function of the charger. Now, left for a while, this extra power that has not fully absorbed is either absorbed, or disapated.
That is one of the reasons that chargers taper off the charge amperage tword the end of a charge. It's called the absorption phase. Low current allowing a more accurate reading, more accurate reading allowing more power to get in the battery whenever possible.
I know the MS lowers charge current when plugged into a high capacity outlet, though, not to the point that the slow current coming out of a 110/120 line would be.
Hope that helps!
What happens in my opinion, is with a quicker higher capacity charge, the "surface charge" (Higher Voltage reading due to the electricity not being absorbed quick enough into the battery) can result in a pre-mature shutdown of the charger, and a poorer reading of total state of charge.
This is seen more with older lead acid batteries, but the larger the pack, the more noticeable it is.
I can use a Lead Acid battery as a example.
Car battery is "12 volts". Fully charged their about 12.8-13.2 volts depending on the specific type (flooded, Gel, AGM). Now, put it on a automatic charger (or any 12v charger for that matter), when that charger shuts off that the battery is full, the immediate reading is much higher then the normal maximum of 13.2. It could be as high as 15 volts for a short while.
This higher voltage trips the "I'm Full" function of the charger. Now, left for a while, this extra power that has not fully absorbed is either absorbed, or disapated.
That is one of the reasons that chargers taper off the charge amperage tword the end of a charge. It's called the absorption phase. Low current allowing a more accurate reading, more accurate reading allowing more power to get in the battery whenever possible.
I know the MS lowers charge current when plugged into a high capacity outlet, though, not to the point that the slow current coming out of a 110/120 line would be.
Hope that helps!
stopcrazypp
Well-Known Member
Like islandbayy says might be the slower charging providing a more accurate SOC estimate so the charger can charge more fully.
But given the results are repeatable when switching back to 14-50, I suspect it's more likely that the battery was better balanced after that slow charge on 110V. And it might not even have do with the 110V, but rather the long 48 hours plugged in.
On the Roadster, if you leave the car plugged-in when charged on Standard Mode, it'll automatically engage battery balancing. The Model S might have something similar.
But given the results are repeatable when switching back to 14-50, I suspect it's more likely that the battery was better balanced after that slow charge on 110V. And it might not even have do with the 110V, but rather the long 48 hours plugged in.
On the Roadster, if you leave the car plugged-in when charged on Standard Mode, it'll automatically engage battery balancing. The Model S might have something similar.
I too have seen my range drop (getting a max of 234 on standard charge now). I'm wondering if this conditioning theory is correct, how scheduled charging factors in? I only started having this drop after switching to scheduled charging. Does having the charge timer on affect when it can condition?
I had quite a similar experience. For the 1st 4000 miles, would regularly get to 242 - 244. Then for next 1000+ miles when charging, it would get 239 max. I took the charge down to about 10 miles left, and did a proper 90% charge on a NEMA 14-50 (instead of HPWC) and voila, back to 242-244. Wonder if there is indeed something to this "conditioning". I don't think it was vampire losses since I was physically there when the charge hit completed just to make sure ... but still got 239.
I know a few roadster owners that have put 50K miles on it with no appreciable drop off in charge. I will try my best to be less neurotic about it ... but I guess that's just the good/bad part of being an earlier adopter. :wink:
I know a few roadster owners that have put 50K miles on it with no appreciable drop off in charge. I will try my best to be less neurotic about it ... but I guess that's just the good/bad part of being an earlier adopter. :wink:
I just did 4.5 yesterday and my new full 90% charge was 232 this morning vs 242 for the 4.4 ~92% or so. the charge stops exactly at 90% now not over the line like it did before
mknox
Well-Known Member
As a point of reference, I have about 6,000 miles on the car and charge at 16 amps / 240 volts at home and 15 amps / 208 volts at work. I always get 242 miles of range on a Standard charge, although it will start to fall due to the "vampire" draw as it sits.
spatterso911
P100DL - Raven
I'm presuming you are still on either 4.3 or 4.4?? Can you share which version firmware you are running?? Thanks!
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