Thoughts on a Tesla Model 3

[Guest]

So, the ffe uses the 12v battery to power all the computer stuff when sitting (which is considered a design flaw with all the 12v issues it has) but the tesla uses the lithium battery for this? And there is that much stuff running in the backround to draw down the lithium battery that much? Is this correct?

 

[triangles]

jmueller065, I read that article about vampire drain. I think part of the problem is there is no "off" button on the Tesla. You literally get out and walk away when the phone key gets out of BT range the car locks and "shuts down." Apparently Tesla's TMS is always active. Although supposedly disconnecting the 12V does shut everything down and disconnects all loads on the HV battery.

Carbuff, I consider the "design flaw" of the ffe the fact that there is nothing to prevent misbehaving modules from drawing on the 12V when they should be off and no data logging of what didn't shut down when it should have. By design the FFE and for that matter any car with keyless entry must have a small load on the 12V battery since you can't monitor for the presence of a fob without power. Most cars can do this with well under a 50mA load on the 12V battery. Most automotive 12V batteries should last more than a month with this type of load.

Since heat damages a lithium battery I supposed I could live with some vampire drain in extreme heat but there's no excuse for it sitting in a 71F garage. Cold really doesn't harm a battery so there's no need to waste energy to heat the battery. The only cold consideration I am aware of is that you really should heat the battery before you charge it when it is cold to avoid battery damaging reactions that happen at subfreezing temps.

If the Tezlab app is accurate I lose about 14 miles of range per day the car just sits. :shock: That's almost 100 miles per week!!! Hopefully they can fix this with an OTA. If not, I found a key fob controlled 12V disconnect switch when I was at my wits end with my FFE 12V issues. I think this may be what I use with my Tesla to stop the HVB vampire drain when I park the car for extended periods of time. The 8.5mA draw on the 12V battery should not be a problem and if I put the battery on a tender, in theory I should be able to store it for years and only lose a few battery %. Not that I would, it's too much fun to drive.

 

[jmueller065]

Is that 14 miles of range lost for sitting an 8 hour workday, or 24 hours, or overnight? That is a pretty significant amount that would add up over a week or month.

 

[jmueller065]

Sabotage! LOL
https://www.cnbc.com/2018/06/18/elon-musk-email-employee-conducted-extensive-and-damaging-sabotage.html

Wow... pretty serious if they have proof, if not then its just paranoia!

 

[triangles]

Thanks I now have that Beastie Boys song going thru my head :lol:

That's 14 miles/24h. TBH I don't know that I trust that figure. The manual says 1% per day which is more like 3ish miles/24h which is still unacceptable IMHO. I have seen rumblings on another forum that the Tezlab app either exaggerates or causes increased vampire drain by pinging the car too often not allowing it to go to sleep. Below is what my app says for the past 7 days.

It also shows the past 30 days which looks the same to me but then again I've only had the app for about a week. I suspect it's also including the energy used for preconditioning as vampire drain. That would make a lot of sense as the tallest bar on the graph that I interpret as yesterday was the hottest with the most preconditioning.

When I first got the car I let it sit for 3 days and it lost several miles, probably about 10ish. I wasn't keeping track so I don't have exact numbers I just remember noticing I had about 10 fewer miles. I initially shrugged this off as a guess-o-meter error but now realize it was vampire drain. This seems to be more inline with 3ish miles per day or about 1% in the manual.

 

[jmueller065]

That is true the instrumentation you're using to measure the drain may have an affect on the system that should be accounted for.

 

[Guest]

Hey, as long as it doesnt burst into flames you should be ok.

http://money.cnn.com/2018/06/18/technology/mary-mccormack-tesla-fire/index.html

Maybe it was more sabotage? LOL.

 

[campfamily]

That is true the instrumentation you're using to measure the drain may have an affect on the system that should be accounted for.

Schrödinger's Cat?

Sorry, a bit early for quantum mechanics humor.....

Keith

 

[triangles]

Just found this in my email. apparently the app emails me a daily report. What was clipped just off the top of the screen grab is that I drove 78mi in the last 7 days. The 99% efficiency means my driving was just under what the guess-o-meter thinks I should have been able to drive. Then it breaks out how energy from the battery was used.

Looks like the sabotage was real! Disgruntled employee who didn't get the promotion he wanted. They must have caught him in the act or something.

 

[triangles]

So after having a Model 3 for a couple months I thought I'd post a little update. Probably the biggest difference between the way the TM3 and FFE drives is the regenerative braking. The FFE complicates things trying to blend regen with physical braking. With a Tesla things are a little more simple. You "throttle" the amount of regen by how much you lift on the accelerator. Full regen = no foot on accelerator. The brake pedal is simply just the physical brakes. Under typical driving with the TM3 you are going single digit speeds when you use the physical brakes to come to a complete stop. Almost 1 pedal driving. I absolutely love that creep can be disabled and the Hold function which allows you to take your foot off the brake pedal and not worry about rolling away. I still would like an easier way to freewheel as sometimes I like to just coast down to a stop and it's very difficult to find the spot where you aren't using any regen and aren't supplying any power to the wheels. Putting the car in neutral while a little awkward seems to work for this. There is a bar graphic right under the speedo that gives a quick visual cue as to the amount of regen or power being expended that makes controlling throttle and regen much more elegant.

And sadly while vampire drain is real with a Tesla, the 3rd party apps such as screen grabs I posted above seem to be wildly inaccurate and can actually cause greater vampire drain. I've stopped using all 3rd party apps and my car has done several OTA updates since then. So not sure what really happened but vampire drain is minimal for the brief times I don't drive it. I'll revisit this in the winter when I'm driving it less. I may end up installing a 12V disconnect as mentioned above for instances of long term storage or simply unhooking the 12V battery.

 

[Fat Focus]

I drove my 81 year old mother's TM3 the other day. It's certainly 2 or 3 times the car my Focus Electric is. Being 6-2, 250 it is not the easiest getting in an out, but it's comfy while driving.

 

[jmueller065]

So after having a Model 3 for a couple months I thought I'd post a little update. Probably the biggest difference between the way the TM3 and FFE drives is the regenerative braking. The FFE complicates things trying to blend regen with physical braking. With a Tesla things are a little more simple. You "throttle" the amount of regen by how much you lift on the accelerator. Full regen = no foot on accelerator. The brake pedal is simply just the physical brakes. Under typical driving with the TM3 you are going single digit speeds when you use the physical brakes to come to a complete stop. Almost 1 pedal driving. I absolutely love that creep can be disabled and the Hold function which allows you to take your foot off the brake pedal and not worry about rolling away. I still would like an easier way to freewheel as sometimes I like to just coast down to a stop and it's very difficult to find the spot where you aren't using any regen and aren't supplying any power to the wheels. Putting the car in neutral while a little awkward seems to work for this. There is a bar graphic right under the speedo that gives a quick visual cue as to the amount of regen or power being expended that makes controlling throttle and regen much more elegant.

And sadly while vampire drain is real with a Tesla, the 3rd party apps such as screen grabs I posted above seem to be wildly inaccurate and can actually cause greater vampire drain. I've stopped using all 3rd party apps and my car has done several OTA updates since then. So not sure what really happened but vampire drain is minimal for the brief times I don't drive it. I'll revisit this in the winter when I'm driving it less. I may end up installing a 12V disconnect as mentioned above for instances of long term storage or simply unhooking the 12V battery.

The Bolt is setup in a similar fashion: put it in "L" and its in one pedal mode: no creep and taking your foot off the accelerator generates 0.2G of deceleration/regeneration. You can double this to 0.4G by grabbing the regen paddle on the back of the steering wheel (the brake pedal always engages the friction brakes on the Bolt). There also is that sweet spot in the accelerator where you're just coasting but, like you describe, its a bit tricky to find it.

Once stopped, however, you're advised to keep your foot on the brake as the brake lights go off and, if on an incline, it won't hold the stop very well in the Bolt.

 

[triangles]

That makes me like the bolt more. I have no idea how many g's the TM3 regen is. Maybe someday I'll find an app for that. I forgot to mention that the "Hold" function keeps the brake lights illuminated so no one knows you took your foot off the brake. Thank goodness for the TM3 so I don't have to go thru the agony of contemplating buying a GM product. I honestly don't think I could bring myself to do it. Long story for hating GM but suffice it to say I'm not bitter and I don't hold grudges... :lol: If I didn't have friends that work there I'd be happy if they went bankrupt again and weren't bailed out.

I can't wait to see Ford's next EV. Hopefully they abandon the kludgy mixed regen/friction brakes. Except for the regen cutting out when hitting a bump I don't dislike the way the ford brake works other than not knowing for sure where the transition is which makes it hard to maximize regen.

I also forgot to mention that I tried supercharging. After driving from Toledo to the far side of Columbus and back I was down to 7% battery. The TM3 is advertised as being able to add 170 miles in 30 minutes. Well I added 40 miles in about 5 minutes! :shock: If my math is right that's 240mi/30min or 480 mi/hr and the first minute or so the power was slowly ramping up to 118 kW. I can't wait to go on a long distance road trip.

 

[Vibrursan]

Wow! I love to see so many fellow Tesla owners! I'm also waiting for mine to be shipped out, and I hope I made the right decision by trusting this company with my new baby. I heard it's called the best car shipping company, so I hope that those who said that are not wrong. It'd be horrible for it to get damaged on the way. I'm still worried about all the cons I read about it online, some of them even being the ones you listed here. I'm still looking forward to owning and driving it soon (not only because I'd look so cool just staying in the driver's seat while the car drives itself, haha).