Suggestion for Charging and Conditioning

Suggestion for Charging and Conditioning

I live in Toledo, OH, where it has been pretty cold. I drive about 25 miles a day and set my charger to "trickle feed" the battery overnight. By the time I wake up, the battery is charged and the car is off, and no longer charging. Although I have a semi-heated garage, the interior of my Model S P usually reads in the low 50 degrees when I get ready to condition it in the morning prior to going to work.

Here's the issue I have, and one I think can be corrected pretty easily via software:

When I start conditioning my car via my mobile app, the car draws power from the battery, even though it is plugged into the wall! I believe that this occurs because the car is in the "off" mode after the battery has fully charged. It would make more sense that when I start the conditioning process with the car plugged in, that the car should recognize it is plugged in, and subsequently "turn on" and draw power from the grid and not the battery.

Let me know if you all have been having the same experience and whether or not this update would be helpful for you as well.

DouglasR | 5 marzo 2013

Until they update the software, use the app in the morning to switch charging to range mode while you heat the cabin. That will start the car charging again, and you won't lose range while the cabin is heating. Stop the charging if the car begins to add too many miles so that the battery does not degrade.

nickjhowe | 5 marzo 2013

Pure speculation on my part, but if it IS drawing current from the battery initially, then there must be some benefit in terms of battery life for doing this. Those Tesla battery engineers are pretty damn amazing.

Captain_Zap | 5 marzo 2013

@Douglas R

My understanding is that we are supposed to use the Range Charge mode very sparingly.

DouglasR | 5 marzo 2013


I agree, but I believe the point of the advice is to avoid charging too close to 100%. My suggestion is to turn charging off when rated miles creep up too far. For example, if the rated miles have dropped to 230 by morning, turn on both range charge and cabin warming via the app. Have your morning coffee, keeping an eye on the charging progress, and turn off charging if and when rated miles get up to 245 (probably about 45 minutes). I don't think that should harm the battery.

However, to be on the safe side, we should probably ask a Tesla engineer, as I am clearly just speculating.

petero | 5 marzo 2013

Forgive my ignorance but with a 25 mile, daily, commute, why bother trying to maximize your charge? The garage temperature is conducive enough and unless drjain is going to be driving up a steep hill at 250mph … he/she will have range to burn.

Brian H | 5 marzo 2013

It's not using "Max" that's the problem. That just lifts the lid. It's actually filling up to or near the top which is damaging (unless, some say, you immediately start driving and drawing down). DR is just suggesting a little while to warm the cabin. If you can drop the Amps while doing so, that makes it even better!

drjain06 | 5 marzo 2013

Thanks for the feedback. @petero, you're right, I dont't need the range on a daily basis, but thought being able to condition from the grid would be a way of extending the range on the car overall, especially if you are planning on taking a longer trip. Loving the car so far!

drjain06 | 5 marzo 2013

Also, it would be nice to have the option of adjusting the amps for charging from the mobile app. Right?

drp | 5 marzo 2013

I am not sure what everybody is talking about with "range" charge. The only settings I have are standard and maximum charging. Range and ideal are just simple displays that are pretty much irrelevant.

drp | 5 marzo 2013

I agree that there should be a mobile app for adjusting the amps. I tend to trickle charge overnight at just about 10A.

drp | 5 marzo 2013

Sorry, In the second post above I meant to say "rated range and ideal range are just simply displays…"

noel.smyth | 5 marzo 2013

I park outside in the cold nightly with about 170 rated miles left after a typcal commuting day. I set the amp to 12 and let it trickle all night so it finishes right around when i leave in the morning. when it finishes too soon I do switch to max and start charging while I eat breakfast. this works to get the battery nice so I have regen from the get go. looking forward to a software update to be able to schedule charging - hopefully by setting the desired finish time!

Brian H | 5 marzo 2013

Normal = range
max = ideal

Brian H | 5 marzo 2013

Incorrect, above. Brain vapor lock. \:[

They are measures with different bases. Normal is 90% of full. Max is full. Range is an estimate of "full" = 265, while ideal estimates full as 300 miles.

Interesting that, depending on driving style, some find each to be relevant/informative/realistic. While some find both to be hopelessly optimistic.

nickjhowe | 5 marzo 2013

@drp - the terminology has evolved over the last few months and includes overlapping and confusing definitions.

There is 'Normal' capacity and 'Max Range' (or 'Range') capacity - as shown in the car and the mobile app. These are measures of what the SoC (State of Charge, i.e., %full) the battery is when it stops charging.

Depending on who measures it, what measure you use, and what day of the week it is, 'Normal' is between 91 and 96% of 'max' capacity. There is some question as to whether 'max' capacity really is 'max'. It is quite possible than an '85kWh' battery isn't really 85 at all and might be nearer to 90KWh - with Tesla 'hiding' the top 5KWh to dynamically replaced failed cells, optimize charging efficiency, etc. etc. There also seems to be c.5KWh at the bottom of the battery 'below' 0miles to provide a 'limp home' range of c. 14-15 miles. Whether this is the same 5KWh as the 'hidden' capacity, or whether it is really unicorn tears is a mystery to all except the TM battery engineers.

Rated, Projected, Ideal and Instant are all measures of consumption OR range, as measured in Wh/mile or miles (or the metric equivalents). 'Rated' relates to the EPA measure of 265 miles at max range charge. Ideal is based on the Tesla measure of 300 miles. Projected is a pre-4.0 firmware measure based on average (or ideal) consumption. Instant is based on the last measurement period (10 seconds?)

There might be others as well, and I might have messed some things up due to poor memory. Confusing, huh?

Brian H | 5 marzo 2013

Yeah, the "ideal" was also the EPA, originally. It was a 2-cycle city/highway measure. "Range" is the new 5-cycle test, with hard accel and braking, and some 80 mph spurts. It's what now is referred to as the EPA standard. Interestingly, especially given some recent owner reports, early beta testers were reporting beating (in normal mixed driving at home) the 300 standard by 5+%.

DouglasR | 5 marzo 2013

@nickjhowe -- the term used is "Standard," not "Normal" in the charge settings.

Also, there is a "Range" setting for driving, which limits AC and cabin temperature in order to maximize range.

nickjhowe | 6 marzo 2013

my bad

edavis008 | 6 marzo 2013

In order to trickle charge daily, I just use a 110v outlet. Juice up with my 50 amp plug when needed. Works for me.

jbunn | 6 marzo 2013

We are overthinking this. The car charges to its set limit, then stops. It starts again when it drops a few miles below the set limit. It cycles back and forth indefinatly. Run the heat long enough, and the car will start charging on its own.

I intend to max charge only when needed. Given that 100 percent charge reduces the life of the battery, and the battery has a warranty, it makes sense to me that the car records the number of times max charge is enabled. I would hate to look like a compulsive max charger, when im just heating the cabin.

kayalir | 6 marzo 2013

I experienced the same thing that @jbunn describes. Plugged my car in last night. Woke up this morning to 182 rated miles (60kwh battery at Standard Charge). That's about 6 miles below full capacity because of the vampire drain that happens while the car sits after the car stops charging. Turned on the heat to Hi. Once the range dropped to about 179 or so I noticed it started charging again. Turned off the heat once cabin reached ideal temp and let the car continue to charge.

Brian H | 6 marzo 2013

Just switching to Max Range doesn't cause any problems. Only if you let it go all the way. So it gives more control than just waiting for the SOC to drop far enough. That might take quite a while.

jbunn | 6 marzo 2013

That is true, however im a bit paranoid of tripping any count related to max charging. IF it tracks count, when does it increment? On initiation, or on completion? I dont know, but just want to be cautious.

DouglasR | 6 marzo 2013

@jbunn -- I just read somewhere in these threads (they've been coming fast and furious, so I don't remember where) that, while TM does not recommend routine Max charging, it will have no effect on warranty issues. For what it's worth.

Pungoteague_Dave | 6 marzo 2013

Brian, We have seen speculation that using max range temporarily to heat the battery does not cause problems. That is logical, but how do we know? We do know that faster charging reduces battery life, so I wonder if using the max range setting to bump the battery temp would not be just as bad. My sense is that slow and steady, without going full, is the best way to condition the battery for the long haul.

Brian H | 6 marzo 2013

Today, in Norway, Elon said using Max charge all the time will reduce range slightly. So though it isn't recommended, you can do it with no effect on warranty. And they expect the batteries to still be usable after 10 years. And in the lab they've run them up to 300,000 mile equivalent and they're still in the acceptable range.

So quicher fussin'.